Frequenzgenauigkeit von Silizium-basierten mikroelektromechanischen, passiv kompensierten Resonatoren für Kraftfahrzeug-Anwendungen - Schön, Florian (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2010)

From Radio Telemetry to Ultra-Low Power Sensor Networks - Tracking Bats in the Wild - Dressler, Falko; Ripperger, Simon; Hierold, Martin; Nowak, Thorsten; Eibel, Christopher; Cassens, Björn; Mayer, Frieder; Meyer-Wegener, Klaus; Kölpin, Alexander (IEEE Communications Magazine, 2016)
Sensor networks have successfully been used for wildlife monitoring and tracking of different species. When it comes to small animals such as smaller birds, mammals, or even insects, the current approach is to use extremely lightweight RF tags located using radio telemetry. A new quantum leap in technology is needed to overcome this limitation and enable new ways to observe larger numbers of small animals. In an interdisciplinary team, we are working on the different aspects of such a new technology. In particular, we report on our findings on a sensor-network-based tracking solution for bats. Our system is based on integrated localization and wireless communication protocols for ultra-low-power systems. This requires coding techniques for improved reliability as well as ranging solutions for tracking hunting bats. We address the technological and methodical problems related to system design, software support, and protocol design. First field experiments have been conducted that showcase the capabilities of our system.
UnivIS-Import:2015-10-26:Pub.2015.tech.IMMD.IMMD4.fromra

Front-end implications to multi-standard cellular radios: State-of-the-art and future trends - Vazny, Rastislav; Pretl, Harald; Maurer, Linus; Weigel, Robert (IEEE International Ultrasonics Symposium, 2010)
The present work discusses the implications to the RF front-end for multi-standard multi-band cellular radios by analyzing noise and linearity specifications of the active circuits as well as isolation and insertion loss limits of the involved passive elements. Optimal adjustments of pertinent trade-offs and an outlook into future requirements and trends are presented.
elib2cris::1512001600,vazny2010a
Keywords: Transceivers; cellular radio; RF front-end; multistandard multiband cellular radios; Reconfigurable architectures; RF-Transceiver; digital front-end; 3G mobile communication

Full Physical Layer Simulation Tool to Design Future 77 GHz JCRS-Applications - Lübke, Maximilian; Su, Yanpeng; Cherian, Athira Jess; Fuchs, Jonas; Dubey, Anand; Weigel, Robert; Franchi, Norman (IEEE Access, 2022)
Vehicular communication systems get more and more attention with the upcoming fifth and sixth generation. Hereby, the focus lies on the development of the co-design or co-existence of communications and sensing. So called joints communications and radar sensing systems are seen as one key technology of 6G. As joint systems will have shared waveforms and hardware platforms, there is a huge benefit in cost and space which is one essential argument for the automotive industry. However, to design such a system for new applications like platooning or intersection assistance a physical layer has to be set up to represent the real physical layer properly. The proposed system design closes the lack of such a simulation tool and allows for full physical layer simulations, including e. g. the hardware non-idealities and the channel model for 77 GHz. The whole signal processing chain of the physical layer is built up and will be integrated in the higher layer state-of-the-art simulation frameworks like Veins or Artery in the next step. The communications design is developed in Simulink, whereas the sensing part is discussed. The proposed communications architecture covers several transmission approaches (serial, parallel), a CDMA based spreading, a radio frequency representation, the channel (simulated in a 3D-Ray-Tracing-tool) and the receiver structure (e. g. the synchronisation or the channel estimation). Several design criteria are discussed, like the serial or parallel design architecture, the maximum ratio combining or the phase and frequency compensation method. The whole system architecture is freely available (https://doi.org/10.5281/zenodo.6482565) and in consequence, the different signal blocks and parameters can be enabled or disabled for evaluations according to future design criteria requirements. <br

Full-Wave Analysis of Surface Acoustic Wave Propagation in Planar ZnO-Diamond-Si Structure - Roesler, Ulrike; Weigel, Robert; Meier, Hans; Russer, Peter (Proc. 8th European Frequency and Time Forum, 1994)
elib2cris::1512001600,roesler1994

Fully Integrated Remote Radio Head and Improved Data Transmission for Inductive Power Transfer Systems - Sanftl, Benedikt; Trautmann, Martin; Weigel, Robert; Kölpin, Alexander (2018 IEEE Radio and Wireless Symposium (RWS), 2018)

Fully Integrated Voltage Controlled Oscillator for Novel High-Precision Local Positioning System - Ußmüller, Thomas; Weigel, Robert (European Wireless Technology Conference, 2008)
This paper describes a voltage controlled oscillator optimized for application in a local positioning system. Instead of the traditional VCO topologies an improved version of the Colpitts-oscillator in common-gate configuration has been built. The VCO has a very good figure of merit of -186 dBc/Hz. It has a center frequency of 6.1 GHz and the measured phase-noise is -117 dBc/Hz at an offset frequency of 1 MHz. The power consumption of the presented VCO is only 5 mW.
elib2cris::1512001600,ussmueller2008c

Fully Integrated W-CDMA IF Chip-Set for UMTS Mobiles - Thomann, Wolfgang; Fenk, Josef; Hagelauer, Richard; Weigel, Robert (Radio Frequency Integrated Circuits (RFIC) Symposium, 2001)
A fully integrated Si bipolar IF-receiver and IF-transmitter with on-chip synthesizer for use in third-generation variable duplex W-CDMA mobiles is introduced. Both devices incorporate an IF-synthesizer with on-chip VCO tuning and tank as well as 5th order baseband filters and comply with ARIB W-CDMA and UMTS standards. The devices are mounted in a small outline, 32 pin, leadless surface mount package.
elib2cris::1512001600,thomann2001a

Fully integrated W-CDMA IF-receiver and IF-transmitter including IF-synthesizer and on-chip VCO for UMTS mobiles - Thomann, Wolfgang; Fenk, Josef; Hagelauer, Richard; Weigel, Robert (Proceedings of the Bipolar/BiCMOS Circuits and Technology Meeting, 2000, 2000)
A fully integrated Si-bipolar IF-receiver and IF-transmitter with on-chip synthesizer for use in third-generation W-CDMA mobiles is introduced. Both devices incorporate an on-chip IF-synthesizer with on-chip VCO tuning and tank as well as fifth order baseband filters and comply with ARIB W-CDMA and UMTS standards. The devices are mounted in a small outline, 32 pin, leadless surface mount package
elib2cris::1512001600,thomann2000
Keywords: VCO; UMTS

Fully integrated W-CDMA IF receiver and IF transmitter including IF synthesizer and on-chip VCO for UMTS mobiles - Thomann, Wolfgang; Fenk, Josef; Hagelauer, Richard; Weigel, Robert (IEEE Journal of Solid-State Circuits, 2001)
A fully integrated, dual intermediate frequency (IF) receiver and an IF transmitter, each with on-chip IF synthesizer, for use in third-generation wide-band code division multiple access (W-CDMA) mobiles has been implemented in a standard, high-frequency, Si-bipolar process with an fT of 25 GHz. The IF receiver (318 MHz) and IF transmitter (285 MHz) include a complete phase-locked loop (PLL) and on-chip voltage-controlled oscillator (VCO) with integrated varactors and transformers. The VCOs are used for on-chip local oscillator (LO) generation and operate at four times IF, 1272 MHz and 1140 MHz, for Rx and Tx, respectively. Fully integrated, active, analog base-band filters further increase functionality and integration level. In the receiver, a channel select filter, composed of a fifth-order Chebyshev lowpass filter and a first-order all-pass filter, is implemented. In the transmitter, a fifth-order Butterworth low-pass filter functions as a reconstruction filter. Both devices operate on 2.7-3.3-V supply. The designs comply with ARIB W-CDMA and UMTS standards. Each chip is mounted in a small outline, 32-pin, leadless surface mount package.
elib2cris::1512001600,thomann2001c
Keywords: Analog base-band filter; analog integrated circuit; decibel-linear IF VGA; dual IF receiver; IF synthesizer; IF transmitter; on-chip VCO; UMTS; W-CDMA

Fundamentals and System Design Challenges in Radar-Based Vital Sign Sensing - Michler, Fabian (IEEE Radio and Wireless Symposium (RWS), 2023)

Funksystem mit Reaktanzmischern für Magnetresonanzanlagen - Martius, Sebastian (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2012)

Funktionalisierte Mikrowellenübergänge in eWLB-Technologie - Seler, Ernst (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2015)

Fusion of Nonintrusive Environmental Sensors for Occupancy Detection in Smart Homes - Zimmermann, Lars; Weigel, Robert; Fischer, Georg (IEEE Internet of Things, 2018)
We presented an approach to detect and count occupants using a fusion of environmental sensors from an indoor air quality measurement system. Environmental sensors, as opposed to motion detectors, are nonintrusive, easy to install, low cost, detect nonmoving occupants, do not have dead spots, and can even infer the number of occupants. For this paper, we conducted measurements of carbon dioxide, volatile organic compounds (VOCs), air temperature, and air relative humidity in four student apartments for a total of 49 days. We extracted features from the environmental sensors and selected subsets using correlation-based feature selection. Subsequently, we performed a comparison of the supervised learning models repeated incremental pruning to produce error reduction, naïve Bayes (NB), C4.5 decision tree, logistic regression, k-nearest neighbors, and random forest. We further proposed a method to greatly reduce time and effort of collecting training data in residential buildings. The results indicated that the predictive power of VOC sensing is comparable to that of carbon dioxide. With a simple NB classifier, our approach detected occupancy and estimated the number of occupants with an accuracy of 81.1 % and 64.7 %, respectively.
Keywords: Temperature sensors; Temperature measurement; Air quality; Sensor systems; Intelligent sensors; Humidity; Environmental sensing; indoor air quality; occupancy detection; sensor fusion; smart homes; supervised learning; volatile organic compounds (VOCs)

Future Challenges in R&D with respect to mobile communication basestations - Fischer, Georg (European Microwave Interest Group meeting at European Commission, 2008)
elib2cris::1512001600,fischer2008a

Future of SAW/BAW Devices in Mobile Radio - Maurer, Linus; Ruppel, Clemens; Weigel, Robert; Vazny, Rastislav (International Symposium on Acoustic Wave Devices, 2012)
The popularity of smart-phones has established EDGE/WCDMA/HSPA connectivity as de-facto minimum requirement with respect to cellular standards. This in turn has increased the pressure to lower costs on the Radio-Frequency Front-End (RFFE)setup.To reduce the complexity and to minimize costs and PCB area, the removal of the external inter-stage SAW and/or BAW filters in the receiver (Rx) and transmitter (Tx) front-end (FE) has become a mandatory feature of state-of-the-art full-duplex capable cellular radios in recent years[1].Furthermore, external SAW/BAW filters are an obstacle on the path to a fully configurable RFFE.This article gives a brief overview on recent developments with respect to the distribution of SAW/BAW filters in the RFFE and tries to elucidate the impact of LTE on the future RFFE partitioning.
elib2cris::1512001600,maurer2012

Future trends of integrated millimeter wave six-port receivers - Lämmle, Benjamin; Schmalz, Klaus; Scheytt, Christoph; Kölpin, Alexander; Weigel, Robert (6. Joint Symposium on Opto- and Microelectronic Devices and Circuits (SODC 2010), 2010)
elib2cris::1512001600,laemmle2010b

Galileo/GPS receiver architecture for high sensitivity acquisition - Heinrichs, Günther; Lemke, Norbert; Schmid, Andreas; Neubauer, André; Kronberger, Rainer; Rohmer, Günther; Förster, Frank; Avila-Rodriguez, Jose-Angel; Pany, Thomas; Eissfeller, Bernd; Ehm, Henning; Weigel, Robert (International Symposium on Signals, Systems and Electronics, 2004)
The location requirements for emergency callers and location-based services (LBS) outside urban areas can hardly be fulfilled without Global Navigation Satellite Systems (GNSS). On the other hand, the new European satellite navigation system Galileo will undoubtedly further expand and improve applications for users in many fields by allowing combined use with the Global Positioning System (GPS) in hybrid receivers. This paper describes the main concept of a future large-scale integrated combined Galileo/GPS receiver chipset for consumer applications with particular attention to high sensitivity acquisition.
elib2cris::1512001600,heinrichs2004a

Galileo/GPS Receiver Fixed-Point Implementation using Conventinal and Differential Correlation - Schmid, Andreas; Neubauer, André; Ehm, Henning; Weigel, Robert; Günther, Christoph (ION GNSS ´05, 2005)
elib2cris::1512001600,schmid2005a
Keywords: Receiver Implementation; Galileo; GPS

Galileo/GPS Single Shot Radio Receiver Architectures for Mobile Stations - Ehm, Henning (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2008)

GaN/AlGaN HEMTs for Highly Linear Communication Applications in L-Frequency band - Quay, Rainer; Würfl, Hans-Joachim; Wiegner, D.; Fischer, Georg (GigaHertz Symposium, 2005)
elib2cris::1512001600,quay2005
Keywords: GaN; PA

GaN as an enabling technology for advanced amplifier architectures - Fischer, Georg (Elektrotechnisches Kolloqium, University of Ulm, 2006)
elib2cris::1512001600,fischer2006i

Gas Discharge Impedance and Transmission Line Voltages in a RF Excited CO₂ Slab Laser - Engelbrecht, Rainer; Schulz, R.; Seibert, Günter; Hagen, J.; Schmidt, Lorenz-Peter (Frequenz, 2005)
The impedance of a RF excited gas discharge slab-type CO 2 laser is determined experimentally. The electrode pair is treated as a lossy transmission line to calculate the voltage distribution along the electrodes. Optimum inductances for homogenization of the gas discharge are derived and compared with experimental results.
UnivIS-Import:2015-04-16:Pub.2005.tech.IE.LEH.gasdis
Keywords: Carbon dioxide; Lasers; Lossy transmission line; RF gas discharge

Gate-Level Current Modeling of Digital Integrated Circuits for Conducted Chip Emission Characterization - Gstöttner, Andreas (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2010)

General Combiner Initialization Workflow for All Types of Active Load Modulation Power Amplifiers - Deublein, Alexander; Illmer, Andreas; Musolff, Christian; Weigel, Robert; Fischer, Georg (2024 15th German Microwave Conference (GeMiC), 2024)
A highly trackable and computationally efficient combiner initialization workflow is introduced that can be applied to any type of power amplifier (PA) employing active load modulation (ALM), such as Doherty PAs (DPAs), outphasing transmitters, load modulated balanced amplifiers, and circulator load modulated amplifiers. The workflow is based on a tunable combiner and associated boundary conditions derived from single-transistor load-pull. As a result, the PA's topology is fixed in advance, clearly distinguishing this technique from existing analytical algorithms. The ability to transition seamlessly from load-pull to an educated initial design of the desired ALM scheme is demonstrated using a two-way inverted DPA based on compact models of Infineon's GaN-on-Si transistors at 3.6 GHz. Apart from its inherent single-frequency limitation, which can be overcome by sampling the band of interest, the software-aided nature of the novel design workflow allows both non-reciprocal components and measured data to be included in the tunable combiner, resulting in unprecedented versatilit
Keywords: Active load modulation; Chireix; circulator load modulated amplifier (CLMA); Doherty power amplifier (PA); gallium nitride (GaN); load modulated balanced amplifier (LMBA); outphasing

Generation of Executable Runtime Constrained Random Programs Functional Processor Verification - Bauer, Wolfgang; Kohl, Johannes; Bäsig, Jürgen; Rübesam, Stefan; Fey, Dietmar (ESM 2016, 2016)
The functional verification of multi-issue deep pipeline processor architectures exceeds the complexity level manageable with static test methods. A randomized approach including automatic test program generation leads to instruction sequences not anticipated and reaches the verification requirements. The challenge is to generate programs that on the one hand are deterministic and terminate for all possible inputs and on the other hand cover the entire instruction set. Moreover for out of order architectures the dependencies between instructions must be taken into account and therefore the instruction sequencing must be part of the coverage. In this paper we present a random program generation technique that produces executable runtime self-constraining deterministic random programs for processor verification. The core elements are a template based program flow generation, program termination certainty and runtime error protection. To avoid unpredictable or illegal situations during program execution value constraining blocks are added to program areas with uncertain behavior.
UnivIS-Import:2017-12-18:Pub.2016.tech.IMMD.IMMD3.genera
Keywords: Branch behavior verification; Functional processor verification; Instruction sequence coverage; Random program generation

Generation of high-speed pseudo-random sequences using multiplex-techniques - Sinnesbichler, Franz; Ebberg, Alfred; Felder, Alfred; Weigel, Robert (IEEE MTT-S International Microwave Symposium Digest, 1996)
We report on the design and performance of high-speed pseudo-random sequence generators for NRZ-signals. The hardware is based on multiplexer circuits that multiply the data rate of a 5 Gbit/s pseudo-random sequence to respectively 10 Gbit/s and 20 Gbit/s. We used multiplex-techniques based on the “cycle-and-add property” of pseudo-random sequences. Using both microstrip and coplanar waveguide technology, the circuitry incorporates special high-speed silicon chips. The experimental results demonstrate the feasibility of our approach
elib2cris::1512001600,sinnesbichler1996a
Keywords: pseudo; random; multiplex; cycle; property; coplanar; waveguide; silicon; chip

Generation of precise frequency ramps for FSCW applications with a fractional-N-PLL at 24 GHz - Stelzer, Andreas; Höftberger, Josef; Ettinger, Klaus; Weigel, Robert (33rd European Microwave Conference, 2003)
For industrial microwave sensors operating in continuous wave (CW) mode in general an adequate frequency modulation is required. A common modulation scheme for distance sensors is frequency stepping (FS). In this paper we present a fast and highly accurate stepped ramp generator based on an integrated 24-GHz Silicon Germanium (SiGe) oscillator with fractional-N-PLL stabilization and modulation. Fast and accurate frequency steps are a prerequisite for achieving a good sensor performance. The dynamic behavior is verified by a phase and frequency evaluation of the ramp signal. Frequency overshoot typical for large frequency steps is reduced by a compensation technique in the PLL control signal of the ramp generator and is demonstrated by 100-MHz steps at 24.5 GHz.
elib2cris::1512001600,stelzer2003d

Generative Adversial Network based Extended Target Detection for Automotive MIMO Radar - Dubey, Anand; Fuchs, Jonas; Lübke, Maximilian; Weigel, Robert; Lurz, Fabian (2020 International Conference on Radar (RADAR), 2020)
In recent years, the automotive radar systems has gained substantial interest for different applications of autonomous driving. The performance of most applications likes classification and tracking directly relies on accurate target detection. The state-of-the-art detection pipeline is vulnerable to multi-path reflections, clutter noise, interference from another radar and leads to false or ghost detections. To address this issue, an end-to-end target detection pipeline using a residual based U-Net architecture is proposed. In contrast to the conventional approach, the network directly generates the detection map from range-Doppler map. The network uses a generative adversarial training over multiple real world measurements. We demonstrate that the proposed network can learn effectively to detect extended targets and shows significant improvement under increased noise floor in comparison to the state-of-the-art detection technique

Geometrical demonstration of the VSWR-locus in different reference planes and its applications - Pinarello, Sandro; Müller, Jan-Erik; Weigel, Robert (Microwave Conference, 2009. APMC 2009. Asia Pacific, 2009)
When evaluating the RF robustness of a power amplifier test measurements are performed on a locus of load conditions with constant voltage standing wave ratio (VSWR). The reference plane is normally set at the antenna input terminal where this constant VSWR locus of points represented on a Smith chart is a circle centred on the origin: often 50 Ohm. For design and technology purposes this investigation is performed via on wafer measurement at the transistor level, before the matching network. This implies that a different locus has to be chosen. Previous literature approaches this issue in a purely algebraical way which formulates the relationship between this two loci but leaves peculiar properties of the transformation unrevealed and unused. In this paper the problem is geometrically tackled and solved by reasoning on the nature of the loci and on the properties of the functions involved. The geometrical procedure is then arithmetically formalised as a linear system of equations whose solutions are compared with those of the classical approach. This comparison lead to discover an imprecision in the formulas previously published. The geometrical reasoning reveals a set of peculiar solutions which are traced back to conditions on the S-parameters of the matching network. The outcome of this proof is suitable for a software implementation and can be applied to an automated load-pull measurement set-up.
elib2cris::1512001600,pinarello2009
Keywords: S-parameters; VSWR; antenna input terminal; matching network

Geometric Dilution of Precision in ToA, TDoA and AoA - Zimmermann, Lars (RadioTecC, 2010)
elib2cris::1512001600,zimmermann2010a

Geometric Representation of Disjoint Sum of Products. - Can, Yavuz (Euro Asia 8th. International Congress on Applied Sciences, 2021)

Gesture Recognition to Control a Moving Robot With FMCW Radar - Maiwald, Timo; Gabsteiger, Jasmin; Weigel, Robert; Lurz, Fabian (2024 IEEE Radio and Wireless Symposium (RWS), 2024)
Gesture recognition with radar sensors experienced great scientific interest in recent years and may become an alternative or supplement technology to camera based computer vision. However, most publications focus on static radars, which is not applicable in case of moving robots, where the radar is attached to the robot itself. This paper presents a system for automated radar data acquisition and labeling in context of radar based gesture recognition, mounted on a moving robot. It is used to collect labeled radar data of 4 different gestures to control the robot. In addition, results of a comparably small CNN, which processes range-Doppler- and range-angle-images, achieving 86 % of evaluation accuracy is presented.<br
Keywords: gesture recognition; robot; radar; computer vision; machine learning

Giant-Magnetoresistance-Based Galvanically Isolated Voltage and Current Measurements - Xie, Fei; Weiß, Roland; Weigel, Robert (IEEE Transactions on Instrumentation and Measurement, 2015)
elib2cris::1512001600,xie2015

GLSE Precoders for Massive MIMO Systems: Analysis and Applications - Bereyhi, Ali; Sedaghat, Mohammad Ali; Müller, Ralf; Fischer, Georg (IEEE Transactions on Wireless Communications, 2018)
This paper proposes the class of Generalized Least-Square-Error (GLSE) precoders for multiuser massive MIMO systems. For a generic transmit constellation, GLSE precoders minimize the interference at user terminals assuring that given constraints on the transmit signals are satisfied. The general form of these precoders enables us to impose multiple restrictions at the transmit signal such as limited peak power and restricted number of active transmit antennas. Invoking the replica method from statistical mechanics, we study the performance of GLSE precoders in the large-system limit. We show that the output symbols of these precoders are identically distributed and their statistics are described with an equivalent scalar GLSE precoder. Using the asymptotic results, we further address some applications of the GLSE precoders; namely forming transmit signals over a restricted alphabet and transmit antenna selection. Our investigations demonstrate that a computationally efficient GLSE precoder requires 41% fewer active transmit antennas than conventional selection protocols in order to achieve a desired level of input-output distortion.

gm-Boosted VCO with low power consumption and large tuning range - Ußmüller, Thomas; Seemann, Kay; Weigel, Robert (Microwave Conference, 2007. European, 2007)
A voltage controlled oscillator (VCO) in a rather new topology is presented. The architecture is based on the classical Colpitts oscillator in common-gate configuration. In order to achieve a higher effective transconductance the gate is not biased with a DC voltage. Instead the biasing voltage has a phase shift of 180deg to the signal at the LC-tank. The design goals have been a wide tuning range and a low power consumption with at the same time the least possible phase noise.
elib2cris::1512001600,ussmueller2007
Keywords: CMOS analog integrated circuits; Microwave FET oscillators; Microwave integrated circuits; Microwave oscillators; Monolithic integrated circuits; Voltage controlled oscillators; Circuit topology; Energy consumption; Ring oscillators; Transconductance; Tuning; Phase Noise

GPS/Galileo System-on-Chip with UMTS/GSM Support for Location Based Services Applications - Miskiewicz, Anna; Holm, Andreas; Bachmann, Frank; Hueber, Gernot; Zipper, Josef; Stöger, Claus; Weigel, Robert (Silicon Monolithic Integrated Circuits in RF Systems, 2009. SiRF '09. IEEE Topical Meeting on, 2009)
A single chip receiver for GPS, Galileo, UMTS, CDMA2000 and GSM standards is presented for the first time. The analog Zero-IF front-end features 2 wideband paths for high and low band operation with one integrated wideband VCO. The paths are combined at the mixer and followed by a baseband filter, high resolution I/Q Sigma-Delta ADC (83 dB SNR for GPS/Galileo standard) and reconfigurable digital front-end for additional signal filtering and conditioning. For GPS/Galileo standards, the chip features overall NF of 3.2 dB (with external components) and gain of HOdB in the analog and digital part. The measured in-band IIP3 and IIP2 equal -25 dBm and 20 dBm, respectively. The chip is supplied from 1.5 V and 2.85 V voltage and consumes 66 mA of current. The receiver is fabricated in 0.13 um RF-CMOS technology and housed in a WFBGA-81 package.
elib2cris::1512001600,miskiewicz2009
Keywords: CDMA2000; Galileo; GPS; Location Based Services; multi-standard receiver; System-on-Chip; UMTS

GPS-gestützte Ortung in der Landtechnik - Seebauer, C.; Auernhammer, Hermann; Demmel, Markus; Muhr, Thomas; Weigel, Robert (Proc. Kleinheubacher Tagung, 1995)
elib2cris::1512001600,seebauer1995

Grafikbeschleuniger für Mobiltelefonie/ARM-Architektur - Schedelberger, G.; Wekerle, Martin; Truhlar, G.; Schuster, Irene; Hagelauer, Richard; Weigel, Robert (Informationstagung Mikroelektronik, 2003)
elib2cris::1512001600,schedelberger2003

Graphical based characterisation and modelling of material gradients in porosified LTCC - Steinhäußer, Frank; Talai, Armin; Steiger-Thirsfeld, A.; Kölpin, Alexander; Weigel, Robert; Bittner, Achim; Schmid, Ulrich (Journal of the European Ceramic Society, 2013)
The chemical composition of LTCC (low temperature cofired ceramics) allows the local implementation of air into the sintered substrates by a selective wet chemical etch process. Therefore, LTCC substrates with areas of low as well as of high permittivity can be created without a material combination. The presented graphical method of material component contrast images enables the evaluation of the most important material properties after their local porosification which are their component distribution, their porosification gradient and their residual bearing surface. The graphical method, including focused ion beam and scanning electron microscopy analyses, is applied to different commercially available LTCC types having two porosification states each. The derived mathematical models, suitable for finite element method implementation, allow the characterization of the effective permittivity reduction while keeping a maximum residual surface area for e.g. metallization purposes. The shape of the optimum material distribution function features an ‘air pocket’ of small width and a depth being dependent on the application specific operating frequency.
elib2cris::1512001600,steinhaeusser2013a
Keywords: porosity; dielectric properties; glass ceramics; graphical method; wet etching

Großsignalverhalten von MEMS Varaktoren als Abstimmelement in Duplexfiltern für Basisstationen - Mzyk, Raphael; Fischer, Georg (MikroSystemTechnik KONGRESS 2009, 2009)
Eine Methode zur Abstimmung hochgütiger planarer Filter mit einem MEMS Varaktor wird vorgestellt. Dabei werden auf der Basis von Verhaltens- und Circuit Level Simulationsmodellen sowohl Klein- also auch Großsignalanalysen durchgeführt. Neben einem Abstimmbereich des Resonators von 860 MHz bis 970 MHz wird die hervorragende Linearität mit einem simulierten Intermodulationsabstand IM3 von 76,3 dBc dargestellt. Vor dem Hintergrund einer Verwendung des abstimmbaren Resonators in Duplexfiltern moderner Mobilfunkbasistationen werden zudem Simulationen zur Bestimmung von EVM und ACLR ausgewertet.
elib2cris::1512001600,mzyk2009

Grundlagen der Funksensorik und Identifikation mit akustischen OFW-Sensoren - Reindl, Leonhard; Weigel, Robert (29. Jahrestagung für Akustik (DAGA 03), 2003)
Mittels Oberflächenwellen (OFW)-Bauelemente werden miniaturisierte mikroakustische Identifikations- und Sensorelemente (Transponder) ermöglicht, die ohne eigene Stromversorgung telemetrisch abgefragt werden können (OFW-Funksensorik). In dem Beitrag wird das Funktionsprinzip dieser Transponder erläutert.
elib2cris::1512001600,reindl2003
Keywords: OFW-Sensoren; Funksensorik

GSM900/DCS1800 Fractional-N Frequency Synthesizer with Very Fast Settling Time - Neurauter, Burkhard; Märzinger, Günther; Lüftner, Thomas; Weigel, Robert; Scholz, Markus; Mutlu, Varol; Fenk, Josef (Microwave Symposium, 2001)
This paper presents a programmable phase-locked-loop (PLL)-based fractional-N frequency synthesizer that uses a third-order ΔΣ-modulator. The in-band phase noise of -97 dBc/Hz in the integer-mode and -94 dBc/Hz in the fractional-mode is measured at 30 kHz offset. In addition to offering an ultra-fine frequency resolution of down to 12.4 Hz and very low in-band phase noise this frequency synthesizer offers, with a loop-bandwidth of about 100 kHz, a very fast settling time of less than 95 μs when a 75 MHz jump is applied. This feature enables multiple RF applications, including GSM to send a signal and quickly reset to send another signal to meet high data throughput requirements.
elib2cris::1512001600,neurauter2001

GSM Mobile Phone Localization using Time Difference of Arrival and Angle of Arrival Estimation - Zimmermann, Lars; Götz, Alexander; Fischer, Georg; Weigel, Robert (9th International Multi-Conference on Systems, Signals and Devices (SSD), 2012)
The localization methods time difference of arrival (TDOA) and angle of arrival (AOA) are investigated in their capability of high-resolution detection of GSM signals. Because GSM is of narrowband nature, a bandwidth expansion technique that significantly increases the resolution of TDOA is introduced. The algorithms maximum likelihood estimator (for TDOA), root multiple signal classification and estimation of signal parameters via rotational invariance techniques (for AOA) are proposed as a reference for each method. Simulations conducted with noisy signals and multipath propagation demonstrate the potential of TDOA for GSM localization, especially for search and rescue applications. AOA on the other hand is very sensitive to multipath, and is therefore only recommended for open space scenarios.
elib2cris::1512001600,zimmermann2012a
Keywords: cellular radio; direction-of-arrival estimation; mobile handsets; parameter estimation; radiowave propagation; signal classification; AOA; GSM mobile phone localization

Halbleiter-Schaltungstechnik - Tietze, Ulrich; Schenk, Christoph; Gamm, Eberhard (Springer-Verlag, 2009)
elib2cris::1512001600,tietze2009

HaLoS - Integrated RF-Hardware Components for Ultra-Wideband Localization and Sensing - Heinen, Stefan; Wunderlich, Ralf; Robens, Markus; Sachs, Jürgen; Kmec, Martin; Weigel, Robert; Ußmüller, Thomas; Sewiolo, Benjamin; Hamouda, Mohammed; Kraemer, Rolf; Scheytt, Christoph; Borokhovych, Yevgen (Intech, 2013)
elib2cris::1512001600,heinen2013

HARadNet: Anchor-free target detection for radar point clouds using hierarchical attention and multi-task learning - Dubey, Anand; Santra, Avik; Fuchs, Jonas; Lübke, Maximilian; Weigel, Robert; Lurz, Fabian (Machine Learning with Applications, 2022)
Target localization and classification from radar point clouds is a challenging task due to the inherently sparse nature of the data with highly non-uniform target distribution. This work presents HARadNet, a novel attention based anchor free target detection and classification network architecture in a multi-task learning framework for radar point clouds data. A direction field vector is used as motion modality to achieve attention inside the network. The attention operates at different hierarchy of the feature abstraction layer with each point sampled according to a conditional direction field vector, allowing the network to exploit and learn a joint feature representation and correlation to its neighborhood. This leads to a significant improvement in the performance of the classification. Additionally, a parameter-free target localization is proposed using Bayesian sampling conditioned on a pre-trained direction field vector. The extensive evaluation on a public radar dataset shows an substantial increase in localization and classification performance.<br
Keywords: Multi-task learning; Radar detection; Scene understanding

Hardware Design Challenges and Modulation Schemes in Joint Communication and Sensing - Faghih-Naini, Samira; Sebastian, Caroline; Reißland, Torsten; Weigel, Robert; Scheiner, Benedict (IEEE Microwave Magazine, 2024)

Hardware Toolkit for Rapid Prototyping of Antenna Tuning Systems - Özdamar, Oguzhan; Hagelauer, Amelie Marietta; Weigel, Robert; Solomko, Valentyn (PROCEEDINGS OF THE 2019 IEEE ASIA-PACIFIC MICROWAVE CONFERENCE (APMC), 2019)
CRIS-Team WoS Importer:2020-09-25

Harmonic generation in an L-section of a Rayleigh-type SAW filter - Mayer, Andreas; Mayer, Markus; Ruile, Werner; Chauhan, Vikrant; Wagner, Karl (IEEE International Ultrasonics Symposium 2017, 2017)

Heart failure monitoring with implantable defibrillators - Kirchner, Jens; Beckendorf, Claudia; Paule, Stefan; Czygan, Gerald; Arnold, Martin (Biomedizinische Technik. Biomedical engineering, 2012)
Heart failure is one of the most frequent diseases and a leading cause for hospital admission and death in Germany and other industrialized countries. Two types of impedance sensors are presented that promise to allow improved disease monitoring and hence better therapy adaptation in heart failure patients with an implanted defibrillator: thoracic impedance to estimate the lung fluid status of the patient, and intracardiac impedance for assessment of cardiac hemodynamics.<br

Heavy Ion Induced Single Event Effects Characterization on an RF-Agile Transceiver for Flexible Multi-Band Radio Systems in NewSpace Avionics - Budroweit, Jan; Jaksch, Matthis; Garcia Alía, Rubén; Coronetti, Andrea; Kölpin, Alexander (Aerospace, 2020)
Nowadays, technologies have a massive impact on the design of avionic systems, even for the conservative space industry. In this paper, the single event effect (SEE) characterization of a highly integrated and radio frequency (RF) agile transceiver is being presented which is an outstanding candidate for future radio systems in NewSpace applications and space avionics. The device being investigated allows programmable re-configuration of RF specifications, where classical software-defined radios (SDR) only define an on-demand re-configuration of the signal processing. RF related configurations are untouched for common SDR and developed discretely by the specific application requirements. Due to the high integrity and complexity of the device under test (DUT), state-of-the-art radiation test procedures are not applicable and customized testing procedures need to be developed. The DUT shows a very robust response to linear energy transfer (LET) values up to 62.5 MeV.cm²/mg, without any destructives events and a moderate soft error ra
Keywords: single event effects; heavy ion; software-defined radio; space avionics; RFIC; NewSpace

Hemodynamic Monitoring with an Implantable Pressure Monitor is Improved by Additional Detection of Heart Sounds - Urbaszek, Albrecht; Kirchner, Jens; van Ooyen, André; Skerl, Olaf (Biomedizinische Technik. Biomedical engineering, 2012)
Early diagnosis of cardiac decompensation is essential to improve therapy of heart failure as one of the most cost-intensive chronic diseases worldwide. This can be achieved by remote monitoring of pulmonary artery pressure. An implantable pressure sensor system is developed in a joint research project (COMPASS), funded by the BMBF. The application of pulse contour analysis, which is well established for stroke volume estimation based on aortic blood pressure, to pulmonary artery pressure (PAP) is challenging due to different signal morphology and limited signal resolution. Especially the incisure in the pressure signal which marks valve closure is often not visible. Therefore, it was investigated whether valve closure can be detected by additional use of heart sounds more reliably. Blood pressure of an anesthetized Rhoen sheep was measured in the pulmonary artery with the mplantable pressure monitor COMPASS and, for reference, additionally with commercial pressure catheters (Millar Instruments) in the pulmonary artery, aorta, left and right ventricles. Heart sounds were detected with a 3D accelerometer fixed at the animal’s chest. For reference, valve opening and closure were derived from left ventricular pressure. With PAP only, 6.3% of all cardiac cycles were unusable for PCA at low and medium heart rates, as either valve opening or closure were missed or not correctly identified. At very high heart rates the loss rate increased up to 87%. When both PAP and accelerometer data were used, the loss rate was reduced to 0.1% ... 0.4% for all heart rates. Combining blood pressure analysis with heart sounds improves the detection of valve opening and closure and thus SV estimation, especially at high heart rates. <br

Hidden Electronics - Dudek, Damian; Fettweis, Gerhard; Frey, Lothar; Kissinger, Dietmar; Kutter, Christoph; Mathis, Wolfgang; Lugli, Paolo; Russer, Peter; Weigel, Robert; Wolff, Ingo (2015)
elib2cris::1512001600,dudek2015a

Hierarchische Power-Supply-Analyse in Mixed-Signal ICs. - Brandtner, Thomas; Weigel, Robert (Workshop Analogschaltungen, 2005)
elib2cris::1512001600,brandtner2005
Keywords: Mixed SIgnal; Power Suppy

HIGAPS: A highly integrated Galileo/GPS chipset for consumer applications - Heinrichs, Günther; Schmid, Andreas; Neubauer, André; Rohmer, Günther; Förster, Frank; Avila-Rodriguez, Jose-Angel; Pany, Thomas; Eissfeller, Bernd; Ehm, Henning; Weigel, Robert (GPS World, 2004)
The Highly Integrated Galileo/GPS Chipset (HIGAPS) project has as its primary goal the development of a large- scale integrated Galileo/Global Positioning System (GPS) receiver chipset for consumer applications, with focus on pedestrian and automotive navigation and tracking. This article describes the first steps of the project, looking at the overall concept and initial architecture of HIGAPS. It discusses the HIGAPS receiver concept, radio frequency front-end, acquisition and processing, indoor signal acquisition, and results of the software receiver performance.
elib2cris::1512001600,heinrichs2004c
Keywords: Global Positioning System; GPS; Location Based Services

HIGAPS - a Highly Integrated Receiver Architecture with Enhanced Sensitivity for Combined Galileo/GPS Reception - Ehm, Henning; Weigel, Robert; Schmid, Andreas; Neubauer, André; Lemke, Norbert; Heinrichs, Günther; Winkel, Jón; Rohmer, Günther; Förster, Frank; Kaniuth, Roland; Rodriques, J.A.; Pany, Thomas; et al. (12th Saint Petersburg International Conference on Integrated Navigation Systems, 2005)
elib2cris::1512001600,ehm2005a
Keywords: Galileo

HIGAPS - Hoch-Integrierter Galileo/GPS Empfaenger-Chipsatz - Ehm, Henning (Galileo-Workshop - Technik & Anwendung, 2006)
elib2cris::1512001600,ehm2006

High-Accuracy Emission Simulation Models for VLSI Chips including Package and Printed Circuit Board - Steinecke, Thomas; Goekcen, Mehmet; Hesidenz, Dirk; Gstöttner, Andreas (International Workshop on Electromagnetic Compatibility of Integrated Circuits (EMC Compo), 2007)
The electromagnetic emission of complex very large scale integrated circuits is determined by their operation activity plus the manifold noise propagation paths through the on-chip power routing, the package traces and the planes and traces on the printed circuit board. The design of any emission test board influences the emission finally measured at defined probing connectors. Good simulation models have to serve two main interests: (1) identification of emission-related IC design weaknesses and estimation of measured emission from the IC manufacturer's point of view and (2) identification of emission- related application board design weaknesses and estimation of measured emission from the system manufacturer's point of view. This paper presents a target-leading approach for a full system emission simulation model which serves both the IC and system manufacturer's interests. The simulation model has been created and verified for a 32-bit automotive microcontroller containing 30 million transistors.
elib2cris::1512001600,steinecke2007a
Keywords: 32-bit automotive microcontroller; VLSI chips; electromagnetic emission simulation models; package; printed circuit board; very large scale integrated circuits

High Accuracy Industrial Positioning Sensors Based on Six-Port Technology - Weigel, Robert; Kölpin, Alexander; Vinci, Gabor; Lindner, Stefan; Barbon, Francesco (Kleinheubacher Tagung, 2012)
elib2cris::1512001600,weigel2012c

High-Accuracy True Speed-Over-Ground Measurement Approaches for Rail Vehicles: Comparison of Highly Accurate State of the Art True Speed-Over-Ground Measurement Approaches for Rail Vehicles - Reißland, Torsten; Weigel, Robert; Koelpin, Alexander; Lurz, Fabian (IEEE Microwave Magazine, 2023)
Increasing the use of rail-based passenger transportation, compared to passenger cars, is a key factor in the pursuit of a climate-friendly transport sector. For example, in Germany in 2021, carbon dioxide emissions per person-kilometer produced by long-distance train transportation were 72% lower compared to transportation by passenger cars [1]. To strengthen the competitiveness of rail transport, its reliability and cost from the user's perspective need to be optimized. One way to achieve this goal is to enable higher levels of automation in rail transport, as is being sought in the automotive sector. And just as in the automotive sector, sensor systems are crucial for a reliable estimation of a vehicle's condition. This reliable estimation is a necessary prerequisite for enabling automation functions.
CRIS-Team Scopus Importer:2023-12-01

High dynamic range x-ray flux monitoring system - Hofmann, Thomas; Hertlein, Markus; Uhlmann, Norman (Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2012 IEEE, 2012)
In this paper we present a mono pixel detector with a very high dynamic range for measuring the X-ray flux. The flux monitor system is mainly designed for supplementing and improving existing X-ray systems. When using such monitor devices additionally to other X-ray detectors, the monitor signal has to be calibrated versus the detector signal. A suitable calibration routine and its results are shown. The linearity (signal vs. dose) of the monitor was investigated and a highly linear behavior can be observed. In contrast to that, the used X-ray flat panel detector shows a larger non-linear behavior; therefor.e a non-linear calibration function has to be applied. The monitor was tested in typical computed tomography (CT) applications. Firstly we monitored the primary X-ray flux during a CT measurement close to the X-ray tube. This results in a very high dose rate, but has the benefit that the signal is not distorted by scattered radiation and that the whole detector area can be used for imaging (as e.g. in region-of-interest CT). We also monitored the scattered radiation during a CT measurement. In this case it is necessary to measure very low dose rates. The acquired measurements can be used to correct the projection data of the CT scan to improve CT quality.
elib2cris::1512001600,hofmann2012g
Keywords: X-ray detection; X-ray scattering; calibration; computerised tomography

High-Efficiency Class E Monolithic HBT Power Amplifiers for Wireless Applications - Grebennikov, Andrej; Jäger, Herbert; Weigel, Robert (European Conference on Wireless Technology 2003 (EuWiT), 2003)
Modern trends in wireless telecommunication systems require low cost and highly efficient solutions, which enable a long talk-time. The proposed new circuit design solutions for power amplifiers provide broadband and high efficiency operation conditions and insensitivity to bias voltage variations. For the output matching configuration, a novel Class E parallel-circuit load network, followed by a microstrip L-type matching circuit is introduced. A bias circuit, based on a differential amplifier, provides a constant quiescent current within the voltage range of 2.6-2.9 V. Practical results for high-efficiency linear multi-band and multimode two-stage and three-stage InGaP/GaAs HBT power amplifiers, intended to operate across DCS1800, PCS1900, CDMA2000 and WCDMA frequency bands, with poweradded efficiency of 50% and more, covering the frequency range from 1.7 GHz to 2.0 GHz, are shown.
elib2cris::1512001600,grebennikov2003

High Frequency Characterization of Thin-Film Redistribution Layers for Embedded Wafer Level BGA - Wojnowski, Maciej; Engl, Mario; Brunnbauer, M.; Pressel, Klaus; Sommer, Grit; Weigel, Robert (9th Electronics Packaging Technology Conference, 2007)
We present high frequency characterization of thin-film redistribution layers for an embedded wafer level BGA package technology. This technology is based on a "molded reconfigured wafer" concept where the chip area is not the limitation for external contacts. The flexible thin-film redistribution layers in the fan-out area enable the realization of high-density, low-loss transmission lines with precisely controlled characteristic impedance. Due to low-loss dielectrics and thick copper metallization, we can realize high-Q passives. We show measurement results of coplanar transmission lines with insertion loss 0.2 dB/mm at 60 GHz. We present measurement results of high-Q inductors with inductance values ranging from 2.8 nH to 30 nH and a quality factor of up to 39. The results demonstrate an outstanding potential of the embedded wafer level BGA concept for high frequency SiP applications.
elib2cris::1512001600,wojnowski2007
Keywords: ball grid arrays; coplanar transmission lines; dielectric materials; thin films; Copper; thick copper metallization; frequency 60 GHz; Impedance

High gain operational amplifier implemented in 0.5 μm GaAs E/D HEMT technology - Seitzer, Dieter; Feng, Shen (Electronics Letters, 1994)
A high voltage gain operational amplifier implemented in 0.5 mum GaAs E/D HEMT technology is presented. The amplifier principally consists of a differential input stage and a high gain cascode stage which was developed by Toumazou and Haigh [1]. On-wafer measurement verifies that the amplifier achieves an open-loop voltage gain of 73 dB and a unity-gain bandwidth of 1.78 GHz.
Keywords: HIGH ELECTRON MOBILITY TRANSISTORS; OPERATIONAL AMPLIFIERS

High-k Hafnium Silicate Films on Silicon and Germanium Wafers by MOCVD Using a Single-Source Precursor - Lemberger, Martin; Schön, Florian; Dirnecker, Tobias; Jank, Michael; Paskaleva, Albena; Bauer, Anton; Frey, Lothar; Ryssel, Heiner (Proceedings of the 15th European Conference on Chemical Vapor Deposition (EUROCVD-15), Electrochemical Society, 2005)
In this work, hafnium silicate layers for gate dielectric application in MOS capacitors deposited by MOCVD using a single-source precursor on Si as well as on Ge wafers ate investigated. For Si wafers, thermally stable Hf xSiyOz layers are obtained. In contrary, on nitrided Ge wafers nearly stoichiometric HfO2 layers are formed implying a surface dependent change in deposition kinetics. A post-deposition rapid thermal annealing in oxygen atmosphere eliminates carbon contamination and strongly improves electrical properties, e.g. reduces equivalent oxide thickness and also leakage currents by several orders of magnitude. A drawback is the observed decrease of permittivity with layer thickness which is due to a change in film composition, i.e. to increasing Si content. A pre-deposition rapid thermal nitridation process performed for Ge wafers improves J-V and C-V characteristic
UnivIS-Import:2015-04-20:Pub.2005.tech.IE.LEB.highkh

High Level Modeling of Dynamic Switching Currents in VLSI IC Modules - Gstöttner, Andreas; Steinecke, Thomas; Huemer, Mario (International Workshop on Electromagnetic Compatibility of Integrated Circuits (EMC Compo), 2005)
elib2cris::1512001600,gstoettner2005

High-Linearity 77-GHz SiGe Automotive Radar Front-Ends - Kissinger, Dietmar (IEEE/MTT-S International Microwave Symposium (IMS), 2009)
The harsh automotive environment poses a series of challenging performance demands to integrated 77-GHz radar frontends. Besides a large temperature range of operation, sufficiently large output power of the transmitter and corresponding receiver sensitivity have to be guaranteed. The large dynamic range of the received signal additionally demands a highly linear behaviour of such receiver circuits. This presentation deals with the design of high-linearity integrated receiver frontends and its subcomponents for 77- GHz automotive radar applications based on high-performance SiGe technologies. These include low-noise amplifiers and down-conversion mixer circuits as well as fully integrated receiver frontends. The authors give insight to the design and measurement techniques of state-of-the-art highly linear 77-GHz radar building blocks. Different circuit architectures are investigated and the corresponding designs and performance parameters are presented.
elib2cris::1512001600,kissinger2009c

Highly Accurate Distance Estimation Using Spatial Filtering and GNSS in Urban Environments - El Assaad, Ahmad; Krug, Markus; Fischer, Georg (Vehicular Technology Conference-VTC2016-Fall, 2016)
elib2cris::1512001600,assaad2016c

Highly Accurate Frequency/Time Domain Characterization of Transmission Lines and Passives for SiP Applications up to 65 GHz - Engl, Mario; Wojnowski, Maciej; Weigel, Robert (69th ARFTG Conference, 2007)
Accurate determination of the characteristic impedance determines the accuracy of the characterization of transmission lines and passive devices. In this paper, we present a novel, time-domain based procedure for the complex characteristic impedance determination. The method is insensitive to changes in the reference plane and the parasitic shunt admittance at the probe tips. For highly accurate passives characterization, a modification of the Thru-Reflect-Line (TRL) calibration algorithm is proposed. It enables the use of the TRL method to de-embed components having the ports on different metallization levels. Additionally, a comprehensive overview and evaluation of both frequency and time-domain methods for characteristic impedance determination is included for completeness. We present measurement results of transmission lines and spiral inductors fabricated in MCM-D technology on low-and high-resistivity substrates up to 65 GHz.
elib2cris::1512001600,engl2007
Keywords: calibration; electric impedance measurement; system-in-package; transmission lines; MCM-D technology; SiP; characteristic impedance; spiral inductors; system-in-package; thru-reflect-line calibration algorithm; transmission lines; Admittance; Calibration; Frequency; Impedance; Metallization; Probes; Shunt (electrical); Time domain analysis; Transmission line measurements; Transmission lines

Highly Efficient Multistandard RFIDs Enabling Passive Wireless Sensing - Essel, Jochen; Brenk, Daniel; Heidrich, Jürgen; Reinisch, H.; Hofer, Günter; Holweg, Gerald; Weigel, Robert (Asia Pacific Microwave Conference (APMC), 2009)
This paper presents a highly efficient analog multistandard frontend for passive sensor-enabled RFID transponders. The CMOS only frontend is implemented in a 0.13 µm CMOS technology. The measured overall RF-to-DC power conversion efficiency of the analog frontend for a DC output power of 10 µW is about 7% and the maximum efficiency is about 15% at UHF. An implemented sensor interface consumes 1.4 µA at 1V supply. This interface contains an ultra low-power successive approximation ADC that uses the capacitive charge redistribution technique for its integrated DAC.
elib2cris::1512001600,essel2009c

Highly-Integrated <0.14 mm2D-Band Receiver Front-Ends for Radar and Imaging Applications in a 130 nm SiGe BiCMOS Technology - Aguilar, Erick; Issakov, Vadim; Weigel, Robert (2019 IEEE 19th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, SiRF 2019, 2019)
Two low-power D-band receiver front-ends with competitive performance for radar and imaging applications are presented. The receivers include passive and active singleended-to-differential converters realized as an ultra-compact Marchand-based balun and as a differential-pair-based active balun, respectively. The receivers achieve measured conversion gains (CG) of 24.9dB at 134GHz (active balun) and 20.27dB at 124GHz (passive balun) while consuming 425mW and 330mW correspondingly. A wide bandwidth of 32GHz is achieved for the active variant in the 114-146GHz frequency range while the passive approach achieves a CG > 10dB in the 112-147GHz frequency range. The passive approach achieves a peak conversion gain of 20.27dB at 126GHz. The presented results offer competitive performance and compare favorably to reported receiver front-ends in terms of ultra-small silicon area (0.14 and 0.1mm 2 ). The front-ends are suitable for integration in highly-integrated D-Band radar receiver arrays as well as for high-density imaging arrays.
CRIS-Team Scopus Importer:2019-06-04
Keywords: active balun; D-band; imaging; passive balun; radar; SiGe; wideband receiver

Highly Integrated 4-32-GHz Two-Port Vector Network Analyzers for Instrumentation and Biomedical Applications - Nasr, Ismail; Nehring, Johannes; Schütz, Martin; Dietz, Marco; Nasr, Ismail; Aufinger, Klaus; Weigel, Robert; Kissinger, Dietmar (IEEE Transactions on Microwave Theory and Techniques, 2016)
This paper addresses the miniaturization of microwave vector network analyzers (VNAs) and the future vision of the VNA on a chip. Therefore, a highly integrated two-port VNA with a multioctave bandwidth from 4 to 32 GHz is presented. The proposed system is based on a fully integrated radio-frequency frontend consisting of a two-port stimulus, a four-channel heterodyne receiver, and a wideband testset. The testset is comprised of on-chip multisection directional couplers. The chip is operated inside a hardware demonstrator using a 16-term calibration procedure. The measurement of arbitrary devices under test is in excellent agreement with commercial measurement equipment and showed a mean deviation from the reference measurement of 0.17 dB and 1.29° regarding the forward transmission of a coaxial 30-dB attenuator. The system and receiver dynamic ranges are 44-77 and 82-101 dB at a resolution bandwidth of 100 kHz over the full system bandwidth. The measurements are highly repeatable and are robust against drift over time. As a proof of concept, the developed integrated network analyzers are utilized in a biomedical sensing scenario with an external and an on-chip sensor. Both approaches showed good sensitivity regarding the mixture ratio of binary solutions of ethanol and methano
lhft_intern.bib::schuetz16

Highly Integrated 4–32-GHz Two-Port Vector Network Analyzers for Instrumentation and Biomedical Applications - Nehring, Johannes; Schütz, Martin; Dietz, Marco; Nasr, Ismail; Aufinger, Klaus; Weigel, Robert; Kissinger, Dietmar (IEEE Transactions on Microwave Theory and Techniques, 2017)
This paper addresses the miniaturization of microwave vector network analyzers (VNAs) and the future vision of the VNA on a chip. Therefore, a highly integrated two-port VNA with a multioctave bandwidth from 4 to 32 GHz is presented. The proposed system is based on a fully integrated radio-frequency frontend consisting of a two-port stimulus, a four-channel heterodyne receiver, and a wideband testset. The testset is comprised of on-chip multisection directional couplers. The chip is operated inside a hardware demonstrator using a 16-term calibration procedure. The measurement of arbitrary devices under test is in excellent agreement with commercial measurement equipment and showed a mean deviation from the reference measurement of 0.17 dB and 1.29° regarding the forward transmission of a coaxial 30-dB attenuator. The system and receiver dynamic ranges are 44-77 and 82-101 dB at a resolution bandwidth of 100 kHz over the full system bandwidth. The measurements are highly repeatable and are robust against drift over time. As a proof of concept, the developed integrated network analyzers are utilized in a biomedical sensing scenario with an external and an on-chip sensor. Both approaches showed good sensitivity regarding the mixture ratio of binary solutions of ethanol and methano
lhft_intern.bib::schuetz16

Highly Integrated Flexible Short Range Radio receiver for Wireless Applications from 300 MHz to 1 GHz - Teichmann, Peter (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2011)

Highly integrated fractional-n synthesizer for locatable wireless sensor nodes - Ußmüller, Thomas; Weigel, Robert; Eickhoff, Ralf (IEEE International Conference on Communications, 2009)
Local positioning systems significantly enhance the value of wireless sensor networks (WSN). This paper presents an integrated synthesizer for localization using frequency modulated continuous wave (FMCW) radar. The synthesizer is based on a fractional-n phase-locked loop (PLL) architecture. All components of the PLL are carefully designed with respect to their power consumption, and the digital parts are implemented in current-mode logic (CML). The complete synthesizer was manufactured in a 0.18 mum SiGe BiCMOS process from IBM, and it consumes only 100 mW, achieves a phase noise better than -117 dBc/Hz and has a silicon area of 1.15 mm2. Due to its high integration level and its optimized design, the synthesizer achieves low power consumption and low phase noise that make it suitable for precise localization in mobile sensor nodes. Localization measurements in indoor environments with multi- path propagation showed mean distance errors about 10 cm.
elib2cris::1512001600,ussmueller2009a
Keywords: FMCW radar; SiGe BiCMOS process; current-mode logic; fractional-n phase-locked loop architecture; fractional-n synthesizer; frequency modulated continuous wave; indoor environment; local positioning system; mean distance error; mobile sensor node; multipath propagation; phase noise; power 100 mW; power consumption; size 0.18 mum; wireless sensor network; CW radar; FM radar; current-mode logic; frequency synthesizers; mobile radio; phase locked loops; wireless sensor networks

Highly-Integrated Low-Power 60 GHz Multichannel Transceiver for Radar Applications in 28 nm CMOS - Issakov, V.; Ciocoveanu, Radu; Weigel, Robert; Geiselbrechtinger, A.; Rimmelspacher, J. (IEEE MTT-S International Microwave Symposium Digest, 2019)
We present a highly-integrated low-power 60 GHz multi-channel transceiver realized in a 28 nm bulk CMOS technology. The circuit integrates three receive (RX) and two transmit (TX) channels. A receive channel includes an LNA, a passive mixer and a transimpedance amplifier (TIA), while a transmit channel contains a three-stage transformer-coupled differential power amplifier (PA). Additionally, the transceiver integrates a local oscillator (LO) signal generation network comprising a voltage-controlled oscillator (VCO), LO buffers, power splitters, frequency divider and a passive distribution network. The VCO is realized as a push-push cross-coupled topology and is continuously tunable in the frequency range 57-to-72 GHz, while achieving a measured phase noise of -84 dBc/Hz at 1 MHz offset at 60 GHz. The entire transceiver dissipates 342 mW using a single 0.9 V supply. A single RX channel draws 33 mA, while a single TX consumes 43 mA. The circuit including pads occupies a chip area of only 1.9 mm × 2.5 mm, which is limited only by the separation necessary for isolation between the channels. The transceiver provides a competitive performance and is suitable for 60 GHz continuous-wave radar applications.
CRIS-Team Scopus Importer:2019-08-09
Keywords: CMOS; radar; transceiver

Highly Integrated Low Power Photomultiplier Readout ASIC Comprising Fast ADC to Be Used in the Antarctic Ice - Schuklin, Dennis; Röber, Jürgen; Stadelmayer, Markus; Mai, Timo; Weigel, Robert; Hagelauer, Amelie Marietta (2019 IEEE 19th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2019)
After the successful launch of IceCube, the work is currently concentrated the next generation neutrino observatory at South Pole, IceCube Gen2. The neutrino detection and post processing accuracy mostly relies on used electronic hardware. The proposed highly integrated, low power photomultiplier readout ASIC is designed for function in low temperatures of Antarctic. The microchip comprises an input pre-amplifier, a clock generator and an ADC with encoder logic featuring sampling rate of 500MHz, 6bit output accuracy with a smart extension of input related resolution up to 8bit in the area of interest. It achieves the same accuracy like a standard 8bit ADC architecture but with significantly less hardware overhead and power dissipation.<br

Highly Integrated Microwave Vector Network Analysis Circuits and Systems for Instrumentation and Sensing Applications - Nehring, Johannes (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2017)

Highly-Integrated Radio Frequency Integrated Circuits (RFICs) for UMTS - Weigel, Robert (Gesellschaft für Mikro- und Nanoelektronik (GMe) Tagung, 2001)
This paper will report on the RF-related system and radio frequency integrated circuit (RFIC) issues of 3G W-CDMA systems like UMTS, technologies that will play a major role in the future of wireless telecommunications allowing for networks which will add broadband data to support video, Internet access, and other high speed data services for untethered devices. It will also address the founding of the company DICE in Linz as an Infineon Technologies Development Center.
elib2cris::1512001600,weigel2001b

Highly-Integrated Scalable D-band Receiver Frontend Modules in a 130 nm SiGe Technology for Imaging and Radar Applications - Aguilar Mendoza, Erick; Issakov, Vadim; Weigel, Robert (2020 German Microwave Conference (GeMiC), 2020)
Two highly integrated, scalable D-Band receiver front-ends based on active and passive baluns which integrate a D-Band signal generator developed in a 130 nm SiGe technology are presented. The presented circuits exhibit a wide tuning range of 19 GHz around 110 GHz and achieve high conversion gains >20 dB and >12 dB for the active-based an passive-based approaches correspondingly. The new chips offer robust solutions for high-gain or high-linearity receivers while showing an extremely compact form factor. Both chips show competitive performance compared with state-of-the-art solutions. Due to their highly reduced area without compromising the power consumption, they can be directly integrated into high-density sensor arrays for imaging and radar applications. <br

Highly Linear IQ Downconverter for Reconfigurable Wireless Receivers - Dufrene, Krzysztof; Weigel, Robert (EUMW - European Conference on Wireless Technology (ECWT 2005), 2005)
elib2cris::1512001600,dufrene2005a
Keywords: IQ Demodulator

Highly linear low-voltage IQ downconverter for reconfigurable wireless receivers - Dufrene, Krzysztof; Weigel, Robert (The European Conference on Wireless Technology, 2006)
elib2cris::1512001600,dufrene2006

Highly linear robust RF switch with low insertion loss and high power handling capability in a 65nm CMOS technology - Rascher, Jochen; Pinarello, Sandro; Müller, Jan-Erik; Fischer, Georg; Weigel, Robert (2012 IEEE 12th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2012)
This work reports on the considerations for building RF switches in deeply scaled CMOS. As demonstrator single pole single throw (SPST) switches in a standard 65 nm technology are designed and measured. Goal of this design is lowest insertion loss while achieving high power handling capability, linearity, and robustness. For the novel design of switch variant Dev 1 0.8dB of insertion loss, 30dBm of power handling and an input third order intermodulation intercept point (iIP3) of 48.8 dBm has been achieved at 1.8 GHz. High robustness is achieved by stacking 4 transistors. Isolation at 1.8 GHz is better than 22dB. For high power handling capability in off state a method is implemented to rise the DC voltage level at inner nodes of the switch. Thus the threshold voltage lowering in deeply scaled CMOS can be counteracted. The small and large signal behaviour of the switch is compared to conventional designs and benefits are proven.
elib2cris::1512001600,rascher2012

Highly sensitive microwave resonant near-field sensor for precise aqueous glucose detection in microfluidic medical applications - Schwerthöffer, Udo; Weigel, Robert; Kissinger, Dietmar (IEEE Instrumentation and Measurement Technology Conference, 2014)
elib2cris::1512001600,schwerthoeffer2014

High performance microwave acoustic components for mobile radios - Pitschi, Maximilian; Kiwitt, Jürgen; Koch, Robert; Bader, Bernhard; Wagner, Karl Christian; Weigel, Robert (Ultrasonics Symposium (IUS), 2009 IEEE International, 2009)
Due to their outstanding characteristics acoustic components, such as SAW and - later on - also BAW filters, have been key components in wireless communication systems from their very beginning. Regarding mobile radio handsets the primary field of application of acoustic components has moved to the RF front-end sections. Here, with the increasing demand for WCDMA-FDD capable mobile phones, duplexers, which allow to separate the TX and RX paths while being simultaneously connected to the antenna, have become indispensable. Regarding the specifications of the different operating bands the requirements on form factors, pass band characteristics, attenuations of the other signals (TX, RX, GPS, WLAN, ...), and isolations make them high performance components requiring a sophisticated acoustic as well as electromagnetic design. Due to the tough requirements imposed on the duplexers in terms of, e.g., center frequencies, spacings of RX and TX bands, relative band widths, and shape factors, they also require application-specific acoustic structures. As a consequence, in contrast to standard filters, duplexers are highly optimized components using leading-edge technologies. In order to achieve the best balance of the characteristic properties of the acoustic structures regarding, for instance, their quality factors, pole-zero distances, and temperature coefficients, the manufacturing processes of the acoustic chips are designed for the specific applications. Furthermore, optimizing the electrical characteristics a co-design of package and acoustic chip is applied. In this paper we provide an overview of the different types of duplexers that have been the result of the focused specialization and optimization efforts. We classify them according to the type of acoustic structures, matching circuitry, and package being used. So far, purely SAW-based and BAW-based duplexers as well as hybrid duplexers using both SAW and BAW chips have been reported. Most of the matching circuitry- is integrated in, for instance, an LTCC package using a distributed approach based on a lambda/4 line or a lumped approach comprising coils and/or capacitors. Sometimes the matching circuitry is realized externally on the PCB. Furthermore, we present recent integration successes, i.e., duplexer inserts, allowing the seamless integration of duplexers into modules without drawbacks on performance or module thickness.
elib2cris::1512001600,pitschi2009
Keywords: BAW filters; RF front-end sections; WCDMA-FDD; duplexers; shape factors; surface acoustic waves

High Performance Mobile Communication Front-Ends in the GHz Range Using Low Loss SAW-Filters - Biebl, Erwin; Anemogiannis, Kimon; Weigel, Robert; Russer, Peter (Proc. IEEE Ultrasonics Symposium, 1991, 1991)
Novel SAW (surface acoustic wave) antenna-duplexers at 900 MHz and 1.684 GHz are presented. Each of the front ends consists of a transmitter path containing a SAW filter for noise suppression, a receiver path containing SAW filters and low-noise amplifiers, and a duplexing circuit. For the 900-MHz FDMA (frequency-division multiple access) mobile radio system the SAW filters must provide both filtering and diverging. The selectivity of the front end has been enhanced by a sophisticated design of the microstrip antenna terminal. For the European TDMA cordless telephone system, the SAW filters provide preselection and noise reduction, and pin-diode switching is used for time multiplexing. The transmitter path consists of three GaAs-FET low-noise driver amplifiers and the SAW filter. The selectivity of the receiver is enhanced by a stripline filter. The feasibility of the combination of SAW and microstrip technologies for the development of low-cost mobile radio units is demonstrated. Design, fabrication and performance of SAW microstrip front-ends in the low gigahertz range are reported
elib2cris::1512001600,biebl1991
Keywords: mobile communication systems; surface acoustic wave filters; 1.684 GHz; 900 MHz; low-noise amplifiers; microstrip antenna terminal; Radio transmitters; Receivers

High Power and High Bandwidth Digital Three-Way Doherty Power Amplifier - Popp, Daniel; Fischer, Georg (WAMICON 2019, 2019)
This paper introduces an enhanced combiner architecture for high power and high bandwidth Three-Way Doherty Power Amplifier. The combiner is mathematical analyzed and two antithetic digital driven Doherty amplifiers are designed. The first one aims for high Back-off efficiency across the target bandwidth while the second one was designed for direct load matching. Both Doherty amplifiers feature a peak power of 61 dBm. The challenges for designing amplifiers with such high peak power are the absorption of the large transistor parasitics and matching the low impedance environment to the load. The proposed combiner architecture features transformer offset lines at all amplifier cores allowing the cancellation of parasitics as well as optimization for broadband performance. The first Doherty amplifier uses a broadband multi-step transformer for load matching and features high Back-off efficiency across the target bandwidth. It achieves a fractional bandwidth of 36.4% and a peak output power of 61 dBm with a power ripple less than 1 dB. The combiner of the second Doherty amplifier transforms the low impedance environment to the desired load termination. It is able to meet the design goals across the frequency band and even covers a broad region outside the band. It has a fractional bandwidth of 43.5% and a peak output power of 61 dBm with a power ripple less than 1 dB. Both Doherty amplifiers are using 500W GaN HEMT transistors from Wolfspeed. The designs and simulations are done with the corresponding Wolfspeed non-linear model
Keywords: Doherty; Broadband; Wideband; High Power; Three Way; DPA; Enhanced Architecture

High Power Effects on a MEMS-based Tunable Matching Network for Power Amplifier Reconfigurability - Silva Cortes, Victor Arturo; Weigel, Robert; Fischer, Georg; Hagelauer, Amelie Marietta (Latin America Microwave Conference 2016, 2016)
In this work, the thermal effects on a tunable matching network (TMN) based on micro electro mechanical system (MEMS) are investigated. A capacitive MEMS switch acts as the active component in a TMN that provides reconfigurability on the PA architecture. However, the large signal operation of the PA causes the membrane of the MEMS switch to heat up, leading to variations of its intrinsic characteristics. These effects are modeled and their influence on the linearity of the PA addressed. The study is aided by a behavioral model of the capacitive MEMS switch with the additional modeling of the thermal effects that raise due to power dissipation at the MEMS’s membrane. The PA architecture is based on a commercial process design kit for the PA and the geometrical and material characteristics of an available MEMS switch.
elib2cris::1512001600,silva2016b

High-Precision Interferometric Radar for Sheet Thickness Monitoring - Mann, Sebastian; Will, Christoph; Reißland, Torsten; Lurz, Fabian; Lindner, Stefan; Linz, Sarah; Weigel, Robert; Kölpin, Alexander (IEEE Transactions on Microwave Theory and Techniques, 2018)
Contact-less sensing plays an important role in today’s highly automated industrial environment, as modern sensors allow for an increased product quality in high-speed manufacturing lines. Hereby, a measurement system for sheet thickness monitoring in aluminum and steel rolling mills is presented. The presented concept is based on a differential measurement principle using two cooperating six-port radar systems. The radio frequency front-ends are designed in a high density substrate integrated waveguide technology at a frequency of 61 GHz. Furthermore, a detailed analysis of non-ideal behavior of mono-static six-port radar front-ends is presented. Moreover, the measurement principle is evaluated in a simplified measurement setup and the results are compared to previously presented theory. Finally, an overview of modern sensing technology for steel rolling mills is presented and compared to the proposed measurement system considering the important aspects, i.e. update rate, precision, and thickness limi
Keywords: radar systems; interferometry; six-port circuits; microwave circuits; substrate integrated waveguide (SIW); planar waveguides

High Precision Local Positioning for Wireless Industry Automation - Zohny, Amr; Ferizi, Alban; Rose, Richard; Weigel, Robert (Embedded World Conference 2011, 2011)
Wireless local positioning systems (WLPS) are currently becoming more entrenched in several elds. Among their most prominent elds of implementations are smart factories and real-time based active mapping for cultural guiding purposes. The development of such systems began with the realization of the positioning core technology. However, as this technology matured, more abstract system aspects materialized as the forthcoming challenge such as infrastructure demands in terms of ranging capabilities, cell requirements regarding bandwidth and most importantly, the energy obligations of the mobile unit. A popular solution to these system demands presents itself as the frequency modulated continuous wave (FMCW) radar technique. The aim of this paper is to discuss its underlying principle, the latest and most recent improvements in this system architecture
elib2cris::1512001600,zohny2011
Keywords: radar; local positioning; radio position measurement; industry automation

High Precision Wireless Synchronization Receiver for M-Sequence UWB Radio Systems - Hamouda, Mohammed; Sachs, Jürgen; Ußmüller, Thomas; Fischer, Georg; Weigel, Robert (Internation Conference on Ultra-wide Band 2012, 2012)
This work deals with M-sequence UWB Radio architectures for high-precision indoor localization and low data rate radio transmission. So far, UWB M-sequence devices were only used in Radar mode which applies wired synchronization between transmitter and receiver. Radio systems have different architecture since receiver and transmitter are spatially separated from each other. This paper focuses on the phase and frequency synchronization between the clock of the transmitter and receiver. The proposed architecture deals with 10 gigachips per second achieving a high frequency bandwidth ranging from DC upto 5GHz or consequently from 5GHz to 15GHz depending on the device structure. It is very costly and power demanding to process such signals in the digital domain to perform the synchronization. Thus, a low power and low cost technique is introduced using analog blocks for the synchronization achieving a maximum error of 5ps.
elib2cris::1512001600,hamouda2012

High Q-factor Metamaterial Duplex Filters in Suspended Stripline Technology - Geelani, Tumcherla (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2009)

High-Q Inductors Embedded in the Fan-Out Area of an eWLB - Wojnowski, Maciej; Issakov, Vadim; Knoblinger, G.; Pressel, Klaus; Sommer, Grit; Weigel, Robert (IEEE Transactions on Components, Packaging and Manufacturing Technology, 2012)
We investigate high-quality (high-Q) inductors implemented in the redistribution layer (RDL) of the fan-in and fan-out area of an embedded wafer-level ball grid array (eWLB) package. The eWLB is an innovative package technology introduced recently for wireless applications. The technology has outstanding capabilities especially for high-frequency and millimeter-wave package design. We demonstrate that inductors realized in the eWLB fan-out area have negligible substrate losses and lower parasitic capacitances compared to inductors in the eWLB fan-in area. As a result, the inductors implemented in the fan-out area offer significantly higher quality factors and higher self-resonance frequencies. We investigate the effects of the chip-to-package interconnection. We show that the chip-to-package transition creates a bottleneck for the integration of high-Q inductors. We demonstrate the advantages of inductors in the fan-out area of the eWLB on the example of a 6-GHz voltage-controlled oscillator (VCO) chip manufactured in a 65-nm complementary metal-oxide-semiconductor process and assembled in an eWLB package. For the LC tank of this example, we use a 1.1-nH high-Q differential fan-out eWLB inductor to reduce the phase noise. For comparison, we investigate a VCO fabricated with a standard on-chip inductor and assembled in the identical eWLB package. Our measurement results demonstrate lower phase noise and higher output power for all VCOs with inductors embedded in the RDL compared to the reference VCO with the on-chip inductor. The measured phase noise for the VCO with the eWLB inductor in the fan-out area is in the best case 9 dB lower than that of the reference VCO with the on-chip inductor. The presented results prove the integration concept and demonstrate the excellent potential of embedded inductors realized in the fan-out area of the eWLB package.
elib2cris::1512001600,wojnowski2012
Keywords: Microwave measurements; packaging; passive circuits; phase noise; thin-film inductors; wafer-scale integration; voltage-controlled oscillators

High-Q Planar Filter Platform Incorporating Macro MEMS Tuning Elements - Fischer, Georg; Mzyk, Raphael (IEEE International Microwave Symposium, 2009)
Duplex filters as used in infrastructure equipment for wireless networks require high selectivity and high power handling. This typically is contrary to tunability. The contribution shows a planar filter platform based on coupled Metamaterial Split Ring Resonators in suspended stripline configuration. A macro MEMS varactor device with piezoelectric actuation is introduced for tuning. Its characteristics are large tunability, large power handling and moderate Q factor. The degradation of the resonators Q factor is kept low as a loose coupling of the MEMS is assumed. Results of tunable passband characteristics are presented. The impact at system level measured by EVM and ACPR degradation is neglectable thanks to its mechanical inertia. An SDD (Symbolically Defined Device) model suited for ADS that captures the mechanical dynamics by a second order differential equation is presented that can be used with all simulation engines of ADS (S, HB, transient and envelope).
elib2cris::1512001600,fischer2009
Keywords: Split Ring Resonators; High Q; Tunable; filter

High-Q Split Ring Resonators for Tuning and Balun Applications - Lautenbacher, Thomas; Mzyk, Raphael; Weigel, Robert; Fischer, Georg; Kölpin, Alexander (Microwave and Radar Week MRW 2012 Warschau, 2012)
High-Q planar filters based on split ring resonators (SRRs) in suspended stripline technology (SSL) are investigated concerning different purposes. Initially, the SRR is analyzed regarding possibilities for optimization of quality factor Q. Beside this, the tuning potential of SRRs is explained. Therefore, an RF MEMS varactor is introduced together with an examination of its potential coupling methods to the SRR. Furthermore, the incorporation of the functionalities filter and balanced-to-unbalanced transformer (Balun) using one SRR is shown. The introduced concepts are proven by simulations and practical demonstrations.
elib2cris::1512001600,lautenbacher2012
Keywords: Split Ring Resonator; High-Q; Suspended Stripline; tuning; RF MEMS; varactor; balun; reconstruction filter

High Q Transmission Line Structure in Lossy Silicon Technology - Kitlinski, Krzysztof; Donig, Günther; Wohlmuth, Hans-Dieter; Bakalski, Winfried; Weigel, Robert (13th Conference on Microwave Techniques (COMITE), 2005)
elib2cris::1512001600,kitlinski2005a

High Resolution Algorithms Applied to Velocity and Length-of-Travel Measurements in Radar Sensors - Stelzer, Andreas; Pichler, Markus; Weigel, Robert (Asia-Pacific Microwave Conference (APMC), 2002)
This work presents results of the application of high-resolution frequency estimation algorithms to Doppler-radar signals for velocity and length-of-travel calculation. The measurement of velocity or distance of remote targets is a very common task in industrial applications, and especially under rough environmental conditions a radar sensor is the solution of choice. The fast Fourier transformation (FFT) – widely used for signal evaluation – exhibits inherent resolution limitations. Therefore, many high-resolution frequency estimation algorithms have been developed in the last decades, and their application to measured radar data with multiple targets is shown.
elib2cris::1512001600,stelzer2002a
Keywords: Doppler-radar; frequency estimation; velocity measurements; microwave sensors

High-Resolution Direction-of-Arrival Estimation using Distributed Radar Sensors - Fuchs, Jonas; Kasper, Alexander; Lübke, Maximilian; Dubey, Anand; Lurz, Fabian (2022 IEEE Radio and Wireless Symposium (RWS), 2022)
We present an approach to high-resolution direction-of-arrival estimation for distributed radar sensors without the need for synchronization or wired connections. The sensor signals are post-processed and combined after range-Doppler processing achieving a larger virtual aperture and multiple snapshots. The proposed approach is validated via simulations and the effectiveness is compared to other baseline estimators. Finally, the applicability on real data is demonstrated using measurement
Keywords: Radar Signal Processing; Direction-of-Arrival Estimation; Wireless Sensor Networks; Spectrum Estimation

High Resolution Evaluation of Radar Sensors - Stelzer, Andreas; Pichler, Markus; Weigel, Robert (European Microwave Conference, 2002)
elib2cris::1512001600,stelzer2002

High-resolution millimeter-wave tomography system for characterization of low-permittivity materials - Och, Andreas; Holzl, Patrick A.; Schuster, Stefan; Schrattenecker, Jochen O.; Freidl, Philipp F.; Scheiblhofer, Stefan; Zankl, Dominik; Pathuri-Bhuvana, Venkata; Weigel, Robert (IEEE MTT-S International Microwave Symposium Digest, 2020)
Tomographic microwave imaging is employed in numerous industrial applications, e.g., nondestructive testing. However, most existing systems are not suitable for measurements of low-permittivity materials such as gaseous substances or insulating foam with high air content. This paper introduces a 79 GHz high-resolution tomography system enabling characterization of materials with relative permittivity close to one. It is based on fully-integrated frequency-modulated continuous-wave radar transceivers which significantly reduce cost and complexity. A first prototype is built with two radar sensors and a rotary stage to emulate a higher sensor count. The medium-dependent time-of-flight through the area-under-test is evaluated and Tikhonov regularization is applied to solve the inverse problem and reconstruct a 2D image. System simulations and measurements with low-permittivity foam objects confirm the feasibility of this approach.
CRIS-Team Scopus Importer:2021-04-19
Keywords: Millimeter wave radar; Nondestructive testing; Permittivity; Radar imaging; Time of arrival estimation; Tomography

High-Resolution Millimeter-Wave Tomography System for Nondestructive Testing of Low-Permittivity Materials - Och, Andreas; Holzl, Patrick A.; Schuster, Stefan; Scheiblhofer, Stefan; Zankl, Dominik; Pathuri-Bhuvana, Venkata; Weigel, Robert (IEEE Transactions on Microwave Theory and Techniques, 2021)
Tomographic microwave imaging is employed as a method of nondestructive testing in a wide range of industrial applications, e.g., for quality control. However, many low-permittivity materials, such as gaseous substances or foam with high air content, do not provide sufficient contrast to the environment to be measured with existing systems. This article introduces a 77-79-GHz high-resolution tomography system that facilitates the characterization of materials with relative permittivity close to one and very small attenuation. Fully integrated frequency-modulated continuous-wave radar transceivers are utilized as sensors to reduce the system cost and complexity significantly. The medium-dependent time-of-flight between different radar sensors is evaluated to reconstruct the permittivity distribution inside an area-under-test. To solve the underdetermined inverse problem, two methods based on the Tikhonov regularization and total variation regularization are implemented. Individual impacts on measurement uncertainty are investigated. Custom-designed horn antennas ensure a sufficient number of signal paths between the sensors. A prototype is built using two synchronized radar modules and a rotary stage to emulate a higher number of sensors. System simulations and measurements are conducted utilizing various low-permittivity foam phantoms. Successful reconstructions of the 2-D permittivity distribution demonstrate the feasibility of this approach.
CRIS-Team Scopus Importer:2021-01-22
Keywords: Millimeter-wave (mmW) radar; nondestructive testing; permittivity; radar imaging; time of arrival estimation; tomography

High-resolution optical probing of SAW and leaky SAW structures - Holm, Andreas; Wallner, Paul; Ruile, Werner; Weigel, Robert (IEEE Ultrasonics Symposium Proceedings, 1997)
A nondestructive high-resolution technique for the optical detection of surface acoustic wave (SAW) devices is presented. The laser probing technique allows for the measurement of the phase and amplitude of microacoustic fields and waves of SAW components in operation. The phase velocity can be determined directly from the measurements with a relative accuracy of up to 1.5.10-5. We present new experimental results of microacoustic wave propagation phenomena including anisotropic and temperature dependent phase velocity υ, diffraction, and attenuation and compare them to full-wave analysis computations. The minimum detectable surface displacement of less than 1 pm/√Hz allows for the detection of different acoustic modes such as Rayleigh waves and leaky SAWs.
elib2cris::1512001600,holm1997c
Keywords: Acoustic measurements; Acoustic signal detection; Leak detection; Optical attenuators; Optical detectors; Optical devices; Optical surface waves; Phase measurement; Surface acoustic wave devices; Surface acoustic waves

High-Resolution Phase-Sensitive Laser probing of Surface Acoustic Wave propagation - Holm, Andreas; Stürzer, Quirin; Ruile, Werner; Weigel, Robert (Proc. MIOP'95, 1995)
elib2cris::1512001600,holm1995a

High-Resolution Pulse-Based Ultra-Wideband Ground Penetrating Radar System for Detection of Buried Anti-Personnel Mines - Oßberger, Gerald; Waldmann, Benjamin; Weigel, Robert (VDE-ITG-Fachausschuss 9.1: Messverfahren der Informationstechnik, 2006)
In diesem Artikel wird ein boden-durchdringendes UWB-Radarsystem zur Detektion und Lokalisierung von Antipersonenminen (APM) vorgestellt. Das System basiert auf der Aussendung von Subnanosekunden-Pulsen um die erforderliche hohe Auflösung und Materialdurchdringung zu erreichen. Die Leistungsfähigkeit des vorgeschlagenen UWB GPR Systems und der verwendeten signal-verarbeitenden Algorithmen wurde anhand von Messungen an realen APM nachgewiesen.
elib2cris::1512001600,ossberger2006b

High Resolution Time Domain and Frequency Domain Package Characterization up to 65 GHz - Engl, Mario; Schiller, K.; Eurskens, Wolfram; Weigel, Robert (56th Electronic Components and Technology Conference, 2006, 2006)
We present a measurement setup for high resolution time domain and frequency domain package characterization. The measurement setup features a sub-mm spatial resolution, which enables accurate time domain measurements of actual small sized package types. We evaluate common calibration techniques and their suitability for package characterization in order to get most accurate measurement results. Further, we demonstrate the versatile utilization of time domain measurement techniques. Accurate impedance characterization and fault analysis of packages is achieved. In addition, we show frequency domain characterization of packages up to 65 GHz
elib2cris::1512001600,engl2006
Keywords: calibration; electronics packaging; microstrip transitions; millimetre wave measurement; network analysers; time-domain reflectometry; Impedance; Instruments

High speed low power phase accumulators for DDS applications in SiGe bipolar technology - Lämmle, Benjamin; Wagner, Christoph; Knapp, Herbert; Maurer, Linus; Weigel, Robert (Bipolar/BiCMOS Circuits and Technology Meeting, 2009. BCTM 2009. IEEE, 2009)
Two phase accumulators with 10 and 8 bit resolution, 7 and 15 GHz maximum clock rate, and a power consumption of 237 and 302.5 mW for use in direct digital synthesizers are presented. The accumulators are designed to retain phase coherency when a frequency switch is performed and are integrated into a DDS to perform simple measurement. The architecture is described, the circuits analyzed and measurements given. The chips are fabricated in a 0.35 mum 200-GHz fT SiGe bipolar technology and occupy only 1028 times 1128 mum2.
elib2cris::1512001600,laemmle2009b
Keywords: phase accumulator; phase accumulator; SiGe; heterojunction bipolar transistor; frequency synthesizer

High-Speed Resonant Surface Acoustic Wave Instrumentation Based on Instantaneous Frequency Measurement - Lurz, Fabian; Lindner, Stefan; Linz, Sarah; Mann, Sebastian; Weigel, Robert; Kölpin, Alexander (IEEE Transactions on Instrumentation and Measurement, 2017)
Surface acoustic wave (SAW) resonators are used for a broad range of wireless sensing applications, some of them having high demands on the resolution as well as the measurement update rate. This paper presents a new interrogation method for precise and fast frequency determination of passive SAW resonators based on instantaneous frequency measurement (IFM) by a low-cost Six-Port interferometer. By using a delay line, the frequency measurement is reduced to a phase measurement that can be instantaneously evaluated by the Six-Port network. No complex signal processing is necessary providing high update rates and low hardware costs. An in-depth analysis of the system concept and its building blocks is presented and the advantages as well as the limitations are discussed and compared to the current state-of-the-art. Finally, a demonstrator in the 2.4 GHz frequency band shows the feasibility and the precision of the concept with measurement times of only a few microseconds.
elib2cris::1512001600,lurz2017

High Speeds in a Single Chip Impact of SiGe/Si on Millimeter-Wave Devices and Applications. - Kasper, Erich; Kissinger, Dietmar; Russer, Peter; Weigel, Robert (IEEE Microwave Magazine, 2009)
elib2cris::1512001600,kasper2009

High-Temperature Superconducting Resonator-Stabilized Coplanar Hybrid-Integrated Oscillator at 6.5 GHz - Klieber, Ralf; Ramisch, Roland; Weigel, Robert; Dill, Roland; Valenzuela, Alejandro; Russer, Peter; Schwab, Martin (IEEE International Electron Devices Meeting (IEDM), 1991, 1991)
A small-size coplanar oscillator has been designed and entirely fabricated on a 10-mm*10-mm/sup 2/ LaAlO/sub 3/ substrate in superconducting microwave integrated circuit (SMIC) technology. As an active element, a GaAs MESFET has been used. The oscillator is stabilized by a coplanar waveguide transmission line resonator patterned from a YBa/sub 2/Cu/sub 3/O/sub 7-x/ film onto the LaAlO/sub 3/ substrate. The oscillator, operating at 77 K, is characterized by a center frequency of 6.5 GHz and a power output of nearly 5 dBm. A single-sideband phase noise to carrier ratio of -90 dBc/Hz at 10-kHz offset has been attained. The attenuation of harmonics is better than 10 dBc.<>
elib2cris::1512001600,klieber1991
Keywords: barium compounds; High temperature superconductors; Microwave technology; Substrates; Microwave integrated circuits; harmonics attenuation; coplanar hybrid-integrated oscillator; LaAlO/sub 3/ substrate

High-Temperature Superconducting X-Band CPW Band-Pass Filters with Small Bandwidth - Weigel, Robert; Nalezinski, Martin; Valenzuela, Alejandro; Russer, Peter (Proc. Asia-Pacific Microwave Conference, 1993)
elib2cris::1512001600,weigel1993b

High-T/sub c/ superconducting coupled coplanar transmission lines: a 3D-transmission line matrix analysis - Vanselow, Martin; Isele, Bertram; Weigel, Robert; Russer, Peter (IEEE MTT-S International Microwave Symposium Digest, 1992, 1992)
The application of the three-dimensional transmission line matrix (3-D-TLM) approach to straight high-T/sub c/ superconducting coupled coplanar waveguide (CCPW) structures, suitable for high-speed interconnects, is presented. The authors have investigated CCPWs fabricated from laser ablated YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) thin-films on lanthanum aluminate (LaAlO/sub 2/) substrates with 0.5-mm thickness. To represent three-dimensional space, the symmetrical condensed TLM node and a nonuniform discretization scheme are used. The surface impedance of the high-T/sub c/ superconducting film is described by London theory and modeled as a thin TLM network loaded with resistive and inductive stubs. The losses of the substrate are represented by additional conductances connected in parallel. CCPW line-to-line coupling is evaluated. Preliminary experimental results with gold CCPWs on LaAlO/sub 3/ are discussed.<>
elib2cris::1512001600,vanselow1992
Keywords: barium compounds; high-temperature superconductors; high-speed interconnects; inductive stubs; nonuniform discretization scheme; Superconducting transmission lines; Transmission line theory; Waveguide lasers

High-Voltage Analog Switch Inspired by Stacked MOSFET-Based RF Switches - Solomko, Valentyn; Syroiezhin, Semen; Weigel, Robert (IEEE Transactions on Circuits and Systems II: Express Briefs, 2023)
A biasing concept for a stacked MOSFET-based RF switch enabling high DC voltage handling is proposed, making the device suitable for analog switching applications. The biasing network is based on floating bipolar voltage sources generating gate bias voltages for individual transistors in stack in accordance with the applied DC signal. A 10-stack, 2.32 Ω shunt switch implemented in a 65 nm SOI-CMOS switch process demonstrates 0.1 dB bandwidth of 3 GHz with DC voltage handling ranging between –7 V and +17 V and RF power handling capabilities of 26 dBm at 900 MHz in OFF-state.
CRIS-Team Scopus Importer:2023-07-07
Keywords: Actuators; Charge pumps; charge-pump; CMOS switch; Feeds; floating voltage source; high-voltage switch; linear switch; Logic gates; Radio frequency; stacked switch; Switches; Switching circuits; Transistors; tunable devices

High-Voltage CMOS RF Switch with Active Biasing - Solomko, Valentyn; Syroiezhin, Semen; Tayari, Danial; Essel, Jochen; Weigel, Robert (ESSCIRC 2022 - IEEE 48th European Solid State Circuits Conference, Proceedings, 2022)
In this paper a stacked MOSFET (metal-oxide-semiconductor field effect transistor)-based RF (radio-frequency) switch comprising an active biasing circuit is demonstrated. The active biasing circuit regulates the DC voltage at the source-drain nodes of the stack, thus compensating for the self-biasing effect when the switch is exposed to a high-power RF signal. Such operating point regulation improves the robustness of the OFF-state switch against the applied RF voltage. Two high-voltage RF switches - a reference one with the passive resistive bias network and the proposed one comprising the active biasing - have been designed and implemented in a dedicated 130 nm bulk-CMOS (Complementary Metal-Oxide-Semiconductor) RF switch technology. The device with the active biasing circuit has demonstrated 6 V higher RF breakdown voltage comparing to the reference switch (62 V versus 56 V respectively). All other relevant RF parameters of the switch remain unchanged.
CRIS-Team Scopus Importer:2022-11-25
Keywords: Antenna tuning; aperture tuning; compensation; high-voltage switch; leakage; MOSFET switch

High-Voltage MOSFET-Based Stacked RF Switch with Extended Bandwidth Down to DC - Syroiezhin, Semen; Weigel, Robert; Solomko, Valentyn (IEEE Solid-State Circuits Letters, 2023)
State-of-art stacked MOSFET-based RF switches cannot handle DC voltages exceeding maximum ratings of individual transistors in stack. In this paper a shunt switch constructed from stacked low-voltage transistors and capable of handling high DC and AC voltages in OFF-state is demonstrated for the first time. The DC voltage handling capability is achieved by introducing a resistive gate bias network coupled to the poles of the switch. An analytical model of the bias network is presented in the paper. A hardware prototype of the proposed device has been implemented in a dedicated 65 nm RF-switch SOI-CMOS process. The measurements of a 20-stack switch demonstrated peak RF and DC voltage handling of 20 V with the potential for further improvement and state-of-art linearity.
CRIS-Team Scopus Importer:2023-05-05
Keywords: Actuators; CMOS switch; high-voltage switch; linear switch; Logic gates; Radio frequency; stacked switch; Switches; Switching circuits; Transistors; tunable devices; Voltage control; Voltage measurement

Hiperlan/2 and IEEE 802.11a - Two Novel Standards for High Speed Wireless Multimedia Networking in the 5 GHz Band - Huemer, Mario (Elektrotechnik und Informationstechnik, 2001)
Two major standardization bodies, the IEEE in the US, and ETSI BRAN in Europe, have recently approved standards for broadband wireless multimedia communications in the 5 GHz band. The physical layers (PHYs) of the two standards, IEEE 802. 11a and ETSI BRAN Hiperlan/2, respectively, have largely been harmonized, while the medium access control (MAC) layers differ significantly. In this paper we give an overview of the physical layers of the two standards, and we present PHY performance simulation results for typical indoor environments.
elib2cris::1512001600,huemer2001
Keywords: standardization; Hiperlan; wireless

History and outlook for high voltage and high performance SAR A/D converter - Ohnhäuser, Frank; Huemer, Mario (Elektrotechnik und Informationstechnik, 2008)
elib2cris::1512001600,ohnhaeuser2008

Hochfrequenzsystemdesign und Hochfrequenzschaltungsdesign - Weigel, Robert; Maurer, Linus; Springer, Andreas; Eichinger, Ludwig; Fenk, Josef; Pretl, Harald (Gerotron Workshop on Wideband-CDMA, 2001)
elib2cris::1512001600,weigel2001g

Hochfrequenzsystemtechnik - Weigel, Robert (Vieweg Verlag, 1999)
elib2cris::1512001600,weigel1999

Hochfrequenzsystemtechnik - Weigel, Robert (Vieweg, 2012)
Informationstechnik kompakt stellt die theoretischen Grundlagen der Informations- und Nachrichtentechnik zusammen und vermittelt einen Überblick über die wichtigsten Bereiche der Informationstechnik. Es liefert wertvolle Hinweise auf Schwerpunkte einzelner Gebiete und Literaturhinweise für die Weiterarbeit. Berücksichtigt werden derzeit besonders wichtige Gebiete der Informationstechnik mit einem Akzent auf der digitalen Nachrichtentechnik.
elib2cris::1512001600,weigel2012b
Keywords: Hochfrequenztechnik; Signale und Systeme; Filter; Informationstheorie und Quellencodierung; Kanalcodierung; Basisbandübertragung; Modulation; Transformationen

Hochgenaue Fahrzeugeigenlokalisierung mit der Nutzung einer Uniform Zirkularen Antennenanordnung - El Assaad, Ahmad; Krug, Markus; Fischer, Georg (Positionierung und Navigation für intelligente Verkehrssysteme (POSNAV), 2016)
elib2cris::1512001600,assaad2016b

Hochgenaue Modellierung eines 2 GHz SAW-Oszillator-Designs - Eichinger, Ludwig; Sischka, F.; Olbrich, Gerhard; Weigel, Robert (Diskussionssitzung Rauschmessungen für die Kommuikationstechnik, 2001)
elib2cris::1512001600,eichinger2001

Hochintegrierte verlustarme Wellenleiterübergänge zwischen Hohlleiter- und Planarschaltungen - Spranger, Christoph (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2015)

How the Magnetization Angle of a Linear Halbach Array Influences Particle Steering in Magnetic Drug Targeting – A Systematic Evaluation and Optimization - Thalmayer, Angelika; Götz, Kilian; Fischer, Georg (Symmetry, 2024)

Human Activity Classification Using mm-Wave FMCW Radar by Improved Representation Learning - Stadelmayer, Thomas; Stadelmayer, Markus; Santra, Avik; Weigel, Robert; Lurz, Fabian (Proceedings of the 4th ACM Workshop on Millimeter-Wave Networks and Sensing Systems, 2020)
The paper proposes a novel Euclidean distance softmax layer for radar-based human activity classification. The method aims to overcome the angular dependency of classical softmax approaches. Through the freedoms thus gained, the activity classes can be distributed freely within the entire embedded feature space, due to which the dimension of the embeddings and the whole neural network size can be reduced. The performance of our novel deep learning architecture is evaluated for 60 GHz mm-wave radar sensor-based human activity classification. The results show that the proposed approach increases the robustness against random and unknown movements compared to state-of-art representation learning technique

Human target detection and localization with radars using deep learning - Stephan, Michael; Santra, Avik; Fischer, Georg (Deep Learning Applications, Volume 2, 2021)
In this contribution, we present a novel radar pipeline based on deep learning for detection and localization of human targets in indoor environments. The detection of human targets can assist in energy savings in commercial buildings, public spaces, and smart homes by automatic control of lighting, heating, ventilation, and air conditioning (HVAC). Such smart sensing applications can facilitate monitoring, controlling, and thus saving energy. Conventionally, the detection of radar targets is performed either in the range-Doppler domain or in the range-angle domain. Based on the application and the radar sensor, the angle or Doppler is estimated subsequently to finally localize the human target in 2D space. When the detection is performed on the range-Doppler domain, the processing pipeline includes moving target indicators (MTI) to remove static targets on range-Doppler images (RDI), maximal ratio combining (MRC) to integrate data across antennas, followed by constant false alarm rate (CFAR)-based detectors and clustering algorithms to generate the processed RDI detections. In the other case, the pipeline replaces MRC with Capon or minimum variance distortionless response (MVDR) beamforming to transform the raw RDI from multiple receive channels into raw range-angle images (RAI), which is then followed by CFAR and clustering algorithm to generate the processed RAI detections. However, in the conventional pipeline, particularly in case of indoor human target detection, both domains suffer from ghost targets and multipath reflections from static objects such as walls, furniture, etc. Further, conventional parametric clustering algorithms lead to single target splits, and adjacent target merges in the target range-Doppler and range-angle detections. To overcome such issues, we propose a deep learning-based architecture based on the deep residual U-net model and deep complex U-net model to generate human target detections directly from the raw RDI. We demonstrate that the proposed deep residual U-net and complex U-net models are capable of generating accurate target detections in the range-Doppler and the range-angle domain, respectively. To train these networks, we record RDIs from a variety of indoor scenes with different configurations and multiple humans performing several regular activities. We devise a custom loss function and apply augmentation strategies to generalize this model during real-time inference of the model. We demonstrate that the proposed networks can efficiently learn to detect and localize human targets correctly under different indoor environments in scenarios where the conventional signal processing pipeline fails.
CRIS-Team Scopus Importer:2020-10-09
Keywords: DBSCAN; Deep complex U-Net; Deep residual U-Net; Detection strategy; Human target detection; Localization; mm-wave radar sensor; Occupancy detection; People sensing; Receiver operating characteristics

Hybrid C-Tuner IC for 40V/80V Antenna Aperture Tuning Applications - Özdamar, Oguzhan; Syroiezhin, Semen; Weigel, Robert; Hagelauer, Amelie; Solomko, Valentyn (2021 IEEE INTERNATIONAL CONFERENCE ON MICROWAVES, ANTENNAS, COMMUNICATIONS AND ELECTRONIC SYSTEMS (COMCAS), 2021)
CRIS-Team WoS Importer:2022-09-30

Hybrid optimization techniques for the design of SAW-filters - Franz, J.; Ruppel, Clemens; Seifert, Franz; Weigel, Robert (IEEE Ultrasonics Symposium Proceedings, 1997)
SAW filters play a key role in IF filtering in mobile communication systems. Filters based on Single Phase Unidirectional Transducers (SPUDTs) are one of the most interesting SAW structures. One aim in the design of these filters is for example to find a filter geometry with minimum length which fulfils the specifications. The high performance SAW filter designs require the solution of difficult nonlinear optimization problems. We present an optimization scheme for the search of a global optimum of these SPUDT based filters. The method consists of stochastic optimization, e.g., simulated annealing or genetic search, followed by a quasi Newton method. The combination of different optimization methods shows good results for the solution of the difficult optimization problem. The scheme leads to a good overall convergence behavior.
elib2cris::1512001600,franz1997
Keywords: Design optimization; Filtering; Geometry; Mobile communication; Optimization methods; SAW filters; Simulated annealing; Stochastic processes; Surface acoustic waves; Transducers

Hybrid Recursive Active Filters for Duplexing in RF Transmitter Front-Ends - Gottardo, Giuseppe; Donati, Giovanni; Musolff, Christian; Fischer, Georg; Felgentreff, Tilman (Mediterranean Microwave Symposium, 2015)
Duplex filters in modern base stations are designed as cavity filters, which are expensive and have big dimensions. Thanks to the emerging digital technology and fast digital converters, it is possible to transfer the efforts of designing analog duplex filters into digital numeric algorithms applied to feedback structures, operating on power amplifiers in transmitters. The design of a digital baseband feedback applied to the analog power RF amplifiers (hybrid filter) is presented and verified by measurements. The use of multiple digital feedback branches allows the closed loop system to show a periodic band-pass behavior at the output of the RF amplifier with a larger bandwidth up to 500 KHz. Moreover the band pass magnitude reaches up to 17 dB difference between maximum gain and attenuation.
elib2cris::1512001600,gottardo2015a
Keywords: active filter; feedback amplifier; base station; stability analysis; interference suppression; band-pass filters; cavity resonators

Hybrid Recursive Active Filters for Duplexing in RF Transmitter Front-Ends - Gottardo, Giuseppe; Donati, Giovanni; Musolff, Christian; Fischer, Georg; Felgentreff, Tilman (Radio Science, 2016)
Duplex filters in modern base transceiver stations (BTS) provides the channel shape in order to perform common frequency division duplex (FDD) operation. Usually they are designed as cavity filters, which are expensive and have big dimensions. Thanks to the emerging digital technology and fast digital converters, it is possible to transfer the efforts of designing analog duplex filters into digital numeric algorithms applied to feedback structures, operating on power amplifiers in transmitters. This solution provides the shaping of the signal spectrum directly at the output of the radio frequency (RF) power amplifiers (PAs) relaxing the transmitter design especially in the duplexer and the antenna sections. The design of a digital baseband feedback applied to the analog power RF amplifiers (hybrid filter) is presented and verified by measurements. A model to describe the hybrid system is investigated and the relation between phase and resonance peaks in the resulting periodic band-pass transfer function is described. The stability condition of the system is analyzed using Nyquist criterion and defining a safe work region in order to avoid oscillation. A solution involving a number of digital feedback and forward branches is investigated defining recursive structure parameters of the hybrid filter. This last solution allows the closed loop system to show at the output of the RF amplifier a periodic band-pass with up to 500 KHz bandwidth. Moreover, the band-pass magnitude reaches up to 17 dB difference between maximum gain and attenuation.
elib2cris::1512001600,gottardo2016
Keywords: active filter; feedback amplifier; base station; stability analysis; interference suppression; band-pass filters

Hybrid Recursive Active Filters for Frequency Agile Architectures - Gottardo, Giuseppe (COMORA, Cognitive Mobile Radio Workshop - Kognitive Drahtlose Kommunikationssysteme Abschluss Workshop, 2014)
elib2cris::1512001600,gottardo2014a
Keywords: Active filter; feedback amplifier; base station; stability analysis; interference suppression; feedback amplifier; cavity resonators

Hybrid Recursive Active Filters for High Selectivity in RF Transmitter Front-Ends - Gottardo, Giuseppe; Donati, Giovanni; Musolff, Christian; Fischer, Georg; Felgentreff, Tilman (2nd International Scientific Symposium ”Sense. Enable. SPITSE.” 2015, 2015)
Duplex filters in modern base stations are designed as cavity filters, which are expensive and have big dimensions. Thanks to the emerging digital technology and fast digital converters, it is possible to transfer the efforts of designing analog duplex filters into digital numeric algorithms applied to feedback structures, operating on power amplifiers in transmitters. The design of a digital baseband feedback applied to the analog power amplifiers is described making use of a model here verified by measurements. The design of hybrid filters allows the closed loop system to reach up to 20 dB difference between maximum gain and attenuation. Particular attention is dedicated to preserve stability conditions. The proposed architecture has the potential to reduce the cost and size of the RF front-ends.
elib2cris::1512001600,gottardo2015
Keywords: Active filter; feedback amplifier; base station; stability analysis; interference suppression; band-pass filters; cavity resonators

Hybrid Sensing and Communications Receiver Front-End for Mobile Communications Applications - Schuster, Armin; Reißland, Torsten; Weigel, Robert (2023 IEEE MTT-S Latin America Microwave Conference (LAMC), 2024)

Hybrid Solver Strategies in Automotive EMC Simulation - Zitzmann, Martin-Ludwig; Grillmair, R.; Clees, Tanja; Weigel, Robert (17th International Zurich Symposium on Electromagnetic Compatibilty, 2006)
elib2cris::1512001600,zitzmann2006

Hysteresis Compensation Method for Magnetoresistive (MR) Sensors Based on Single Polar Controlled Magnetic Field Pulses - Xie, Fei; Weiß, Roland; Weigel, Robert (IEEE Transactions on Industrial Electronics, 2016)
elib2cris::1512001600,xie2016

IC-in-the-Loop - Ein innovatives Verfahren zur automatisierten Analyse, Verifikation und Re-/Konfiguration von Embedded-Core basierten Chipsystemen - Franchi, Norman; Heinz, Christian (Elektrotechnik, 2010)
Der Veruegbarkeitszeitraum von elektronischen Bauteilen wird immer kuerzer. Obsoleszenz ist ein Problem, fuer das es verschiedene Loesungsansaetze gibt. Die radikalste und teuerste Loesung ist ein komplettes Redesign der gesamten Systembaugruppe rund um eine neue Komponente. Eine angemessene Alternative hierzu ist beispielsweise der Austausch der nicht mehr veruegbaren Hardware mit einer System-on-a-Chip (SoC)-Variante, welche mit eingebetteten Core-Logikbausteinen (Black-Boxes) die jeweils obsolete Schaltungseinheit emuliert. Bei dieser Vorgehensweise werden digitale, analoge und Mixed-Signal-Funktionseinheiten von veralteten bzw. abgekündigten Bauelementen in Form von IP Cores (Hard- sowie Soft-Cores) auf integrierten Schaltkreisen (ICs), wie ASICs oder FPGAs, neuer Chipgenerationen integriert und danach auf redesignten Elektronikbaugruppen verbaut.
elib2cris::1512001600,franchi2010
Keywords: Obsoleszenz; Embedded Cores; SoC; FPGA; VHDL; Redesign

Identification of Microwave Device and Packaging Models from Frequency Response Data - Neumayer, Roland; Stelzer, Andreas; Weigel, Robert (Proceedings International Microwave and Optoelectronics Conference (IMOC), 2003, 2003)
As system integration evolves and package densities increases, it becomes increasingly important to model non-ideal behavior of previously neglected frequency-domain effects of the microwave components and packaging interconnects. This paper addresses the generation of SPICE-based circuit models from frequency-domain response parameters. In particular, a recently developed subspace identification algorithm is applied to generate passive multi-port models of microwave devices and packages characterized by measured or simulated network parameters. Results of the application of the proposed method applied to real-world examples are given.
elib2cris::1512001600,neumayer2003f
Keywords: SPICE; electronics packaging; equivalent circuits; frequency response; frequency-domain analysis; microwave devices; multiport networks; reduced order systems

IIDT-Type Low-Loss SAW Filters used in Wideband Cellular Radio Systems - Weigel, Robert; Bader, Bernhard; Fischerauer, Gerhard; Russer, Peter (IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, 1993, 1993)
The design and performance of wideband low-loss surface-acoustic-wave (SAW) filters employing interdigitated interdigital transducers (IIDTs) suitable for cellular radio systems are described. The filters were fabricated on 36° YX-LiTaO3 substrates. A detailed design method which optimizes the IIDT configuration has been worked out. In the 500-MHz band, fractional bandwidths of up to 5.2% with passband ripples smaller than 1 dB were attained. Insertion loss and sidelobe suppression were at 1.8 dB and 23 dB, respectively
elib2cris::1512001600,weigel1993g
Keywords: cellular radio; frequency response; interdigital transducers; lithium compounds; Band pass filters; Bandwidth; Design methodology; Surface acoustic waves

I_LED_Milchvieh - Ein Beispielprojekt aus dem Themenschwerpunkt „Smart Light“ des Forschungsschwerpunkts Intelligente Technische EnergieSysteme (FSP ITES) - Werner, Daniel (Auftaktveranstaltung „Globale Partnerschaften“, 2015)

Image denoising using bilateral filter with noise-adaptive parameter tuning - Gabiger-Rose, Anna; Kube, Matthias; Schmitt, Peter; Weigel, Robert; Rose, Richard (IECON 2011 - 37th Annual Conference on IEEE Industrial Electronics Society, 2011)
In this work, a novel way to adjust a bilateral filter is presented. The bilateral filter is a combination of domain and range filtering. The domain filter acts as a low-pass filter. The range filter stands for the nonlinear component and plays an important part in edge preserving. Both filtering components can be adjusted by according parameters. Pursuant to our experience and achieved results in terms of the image quality it is more effective to readjust the range filter to the noise level than to cope with the fine tuning of the spatial filter. In this work, we show how the adjustment parameter for the nonlinear range component can be derived from the standard deviation of noise, which allows automatic noise-adaptive adjustment of the filter.
elib2cris::1512001600,gabiger-rose2011b

Impact of Channel Select Filtering on W-CDMA Signal Properties - Maurer, Linus; Schelmbauer, Werner; Pretl, Harald; Springer, Andreas; Weigel, Robert (International Microwave and Optoelectronics Conference, 2001)
Channel select filtering is an important task in the design of a W-CDMA compliant receiver. The influence of filtering on the signal properties like the mean and maximum slew-rate, adjacent channel power ratio (ACPR) and peak to average power ratio (PAR) has been studied. As channel select filtering in a direct conversion receiver is done by simply low-pass filtering the received signal, knowledge of these properties is important for the design of components succeeding the baseband filters (e.g. buffers and amplifiers). This work should provide the necessary knowledge to design these components with correct presumptions on the mandatory slew-rate.
elib2cris::1512001600,maurer2001c

Impact of DC and RF non-conducting stress on nMOS reliability - Cattaneo, Andrea; Pinarello, Sandro; Müller, Jan-Erik; Weigel, Robert (IEEE International Reliability Physics Symposium (IRPS), 2015)
The increase of leakage current in deep-submicrometer MOS transistors operated below threshold is becoming a reliability concern for scaled technology nodes. Especially high-power analog applications like high efficiency PAs and RF-switches undergo to strong lateral field when Vg <;Vth. Indeed an increased degradation for these MOS applications was already reported in the state of the art but not completely understood. In this paper a thorough study of the DC non-conducting (NC) stress is presented and a new physical model describing the worsening of the electrical parameter is proposed. This model is suitable for being extended to the high frequency regime by means of a quasi-static sum (QS). For the first time RF stress measurements are conducted in various NC configurations. No frequency dependency is detected up to 4Ghz and the QS model is able to precisely predict the performance degradation.
elib2cris::1512001600,cattaneo2015

Impact of High Sc Content on Crystal Morphology and RF Performance of Sputtered Al1-xScxN SMR BAW - Bogner, Andreas; Timme, Hans Jorg; Bauder, Rudiger; Mutzbauer, Angelika; Pichler, Diana; Krenzer, Michael; Reccius, Christian; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE International Ultrasonics Symposium, IUS, 2019)
Applications using BAW devices benefit from large intrinsic electromechanical coupling materials, e.g. Al1-xScxN. This work reports BAW-SMRs using high piezoelectric Al1-xScxN and investigates the relations between Sc content, crystal morphology and resonator RF performance. Finally, key requirements for high quality Al1-xScxN thin-film growth are analyzed and discussed examplary for x = 20at.-%.
CRIS-Team Scopus Importer:2020-02-21
Keywords: AlScN; BAW resonator; BAW-SMR; thin-film growth

Impact of IF-SAW Filtering on the Performance of a W-CDMA Receiver - Maurer, Linus; Schelmbauer, Werner; Pretl, Harald; Boos, Zdravko; Springer, Andreas; Weigel, Robert (IEEE Ultrasonics Symposium, 2000)
elib2cris::1512001600,maurer2000

Impact of integration time on detection performance based on field trial results in passive radar - Steck, Markus; Lutz, Steffen; Weigel, Robert (2022 German Microwave Conference, GeMiC 2022, 2022)
This paper provides an overview of the influence of different integration times on the detection performance of a passive radar system. For this purpose., a passive radar processing 16 different FM-transmitters simultaneously was used [1]. The detection performance over the whole airspace as well as a detailed analysis of individual trajectories are examined. Recorded raw-data was processed with different integration times and compared with reference data which was categorized by different airplane-types. A noticeable improvement in the detection performance can be achieved with longer integration times., but it also causes additional challenges for the signal processing [3].
CRIS-Team Scopus Importer:2022-07-15
Keywords: long coherent integration; passive radar; real data measurements; snr improvements

Impact of nonlinear amplifiers on the UMTS system - Springer, Andreas; Frauscher, Thomas; Adler, Bernd; Pimingsdorfer, Dieter; Weigel, Robert (2000 IEEE Sixth International Symposium On Spread Spectrum Techniques And Applications, 2000)
We report on the impact of distortions caused by a nonlinear amplifier on the performance of a transmitter for the Universal Mobile Telecommunications System (UMTS). A system overview of the UMTS Terrestrial Radio Access (UTRA) physical layer is given. System simulations of an UMTS transmitter designed for commercial use are described. The degradation of the UMTS transmit signal in terms of error vector magnitude (EVM) and adjacent channel power ratio (ACPR) is discussed and related to the power amplifier (PA) characteristics like 3 rd order intercept point and 1 dB compression point. Furthermore the impact on the uncoded bit error rate is investigated.
elib2cris::1512001600,springer2000a

Impact of SAW RF and IF filter characteristics on UMTS transceiver system performance - Pimingsdorfer, Dieter; Holm, Andreas; Adler, Bernd; Fischerauer, Gerhard; Thomas, Ralf; Springer, Andreas; Weigel, Robert (IEEE Ultrasonics Symposium, 1999)
This paper reports on the application of SAW filters in the Universal Mobile Telecommunications System (UMTS), the new third generation mobile communication system. A brief system overview of the UMTS Terrestrial Radio Access (UTRA) physical layer standardized by the European Telecommunications Standards Institute (ETSI) will be presented. System simulations of a UMTS transceiver designed for commercial use are discussed. SAW filters are applied in both the transmit and receive path of the RF and IF parts. The correlations between filter characteristics, like group delay ripple, effective magnitude and phase errors, and system characteristics, such as Error Vector Magnitude (EVM), are evaluated. Such kind of system simulations covers not only the system design itself but also governs the design of SAW filters since it accounts for the special influence of the SAW RF and IF filter characteristics on the UMTS system performance
elib2cris::1512001600,pimingsdorfer1999

Impact of Spatial Distribution of Dissipated Power to Modeling of SMR BAW Resonators at High Power Levels - Tag, Andreas; Bader, Bernhard; Huck, Christian; Karolewski, Dominik; Pitschi, Maximilian; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2015)
elib2cris::1512001600,tag2015b

Impact of technology scaling on electrical characteristics of through-silicon via correlated with equivalent circuits - Lee, Hui Min; Liu, En-Xiao; Li, Er-Ping; Fuhrmann, Jörg (EMC Europe 2011 York, 2011)

Impact of the Array Length on Particle Attraction in Magnetic Drug Targeting – Investigation Using an Exponential Approximation of the Magnetic Field - Thalmayer, Angelika; Götz, Kilian; Zeising, Samuel; Fischer, Georg (IEEE Magnetics Letters, 2023)

Impact of the Local Oscillator on Baseband Processing in RFID Transponder - Cilek, Fatih; Seemann, Kay; Weigel, Robert (International Symposium on Signals, Systems and Electronics, 2007. ISSSE '07, 2007)
The ultra high frequency (UHF) passive radio frequency identification (RFID) technology has gained popularity, because there are improvements regarding read distance and operational reliability. This features and the low-cost passive technology suppose to play an important role in the field of automatic identification and ubiquitous computing. The operation frequency of the UHF transponder (tag) is between 860 MHz-960 MHz. The performance of the tag is limited by physical reasons such as available power for the baseband processing. The baseband functions are specified in EPCtrade class 1 generation 2 UHF protocol, in which a local oscillator generates the clock for the baseband processor. This paper analyzes the influence of the local oscillator to the communication in the baseband.
elib2cris::1512001600,cilek2007

Implantable Antenna for Medical Sensor Platforms - Söll, Christopher; Walk, Jasmin; Fischer, Georg; Weigel, Robert; Ußmüller, Thomas (19th International Conference on Microwave, Radar and Wireless Communications (MIKON), 2012)
elib2cris::1512001600,soell2012

Implementation and Assessment of a Radar Based True-Speed-Over-Ground Estimation Approach Utilizing Complex-Valued Correlation - Reißland, Torsten; Michler, Fabian; Weigel, Robert; Koelpin, Alexander; Lurz, Fabian (2021 18th European Radar Conference, EuRAD 2021, 2022)
This paper presents an approach for improving a previously presented velocity estimation system, dedicated for the application on trains. The systems operation is based on the correlation of the received signals from two radar receivers. So far, only the magnitudes of the signals in range domain were considered in the correlation, as including the phase leads to undesired complexities. These complexities and their handling are presented in this work. Furthermore, the improved approach is compared to the previous approach as well as to competing systems.
Created from Fastlane, Scopus look-up
Keywords: correlation; radar; rail transportation; velocity measurement

Implementation of a High-Speed Flash ADC for High Performance Pipeline ADCs in an 180nm CMOS Process - Löhr, Robert; Kempf, Markus; Ohnhäuser, Frank; Röber, Jürgen; Weigel, Robert; Bänisch, Andreas (International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS), 2015)
Pipeline Analog to Digital Converters (ADC) use a sub-ADC in each pipeline stage. They require a much higher sampling rate and less accuracy. For that reason Flash ADCs are predestined for sub-ADCs. In this paper a differential Flash ADC is presented for a targeted pipeline ADC with 16 Bit, 200 MS/s and a 1.5 Bit resolution per stage. The overall accuracy of the Flash ADC is 30mV and a typical propagation delay of around 400 ps is achieved. This corresponds to a sampling rate of 2.5 GS/s. In addition, a new numerical method for an effective simulation of the propagation delay and offset is presented.
elib2cris::1512001600,loehr2015

Implementation of Binary Orthogonal Keying Schemes Using SAW-Chirp Filters for Robust Wireless LAN Applications - Springer, Andreas; Gugler, Wolfgang; Huemer, Mario; Weigel, Robert (Progress in Electromagnetics Research Symposium (PIERS), 1998)
elib2cris::1512001600,springer1998

Implementation of real-time-control-systems with embedded operating systems - Burglechner, S.; Silber, S.; Grabner, H.; Kaiserseder, M.; Huemer, Mario; Amrhein, Wolfgang (International Symposium on Signals, Systems and Electronics, 2004)
Present control-systems which are addressed by digital fixpoint processors should include the ability to adapt and to reconfigure a system at anytime. Usually this leads to very long flashing routines that can cause heavy problems due to local conditions. Nowadays this should be carried out via a bus system. The presented concept offers the possibility to design a control system graphically. The designed system is loaded down via a bus system to a target hardware. The same bus system can be used to enhance the performance of the application by proper adaption of each single control parameter.
elib2cris::1512001600,burglechner2004

Implementation of Simultaneous Energy and Data Transfer for Charging Electric Vehicles - Trautmann, Martin (4th International Energy Transfer for Electric Vehicles Conference (ETEV), 2015)
elib2cris::1512001600,trautmann2015

Implementation of Simultaneous Energy and Data Transfer in a Contactless Connector - Trautmann, Martin; Joffe, Christopher; Pflaum, Felix; Sanftl, Benedikt; Weigel, Robert; Heckel, Thomas; Kölpin, Alexander (IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2016)
This paper presents a contactless, near ﬁeld energy and data transfer system, which uses one common pair of coils for both transmission purposes. As exemplary target application a contactless connector for harsh environment is shown, but the concept can be adapted to several other applications. The challenge is to transmit the data simultaneously to a high energy signal. The system concept, simulation as well as measurement results of a hardware demonstrator will be presented in this paper. It will be shown that a robust data transmission system can be realized featuring superior SNR and nearly noise free operation even with a simultaneous energy transfer of several kilowatt.
elib2cris::1512001600,trautmann2016
Keywords: data transfer; inductive power transmission; plugs; power filters; wireless communication

Implementierung und Evaluierung eines drahtlosen TDOA-Ortungssystems - Erhardt, Stefan (2011)
elib2cris::1512001600,erhardt2011
Keywords: TDOA; Localization; Hardware; GSM

Improved Calibration Procedure for Six-Port Based Precise Displacement Measurements - Staszek, Kamil; Linz, Sarah; Lurz, Fabian; Mann, Sebastian; Weigel, Robert; Kölpin, Alexander (IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2016)
In this paper an improved calibration procedure for six-port based displacement measurement radar is proposed. The entire system characterizati on is done only using several measurements of the target at kn own positions and no additional calibration standards a re required. The proposed calibration has been experim entally verified for a six-port based displacement measurem ent radar operating at 24 GHz. The performed measurements within the target position range 0 – 18.75 mm prove a significant to the other reported algorithm
elib2cris::1512001600,staszek2016
Keywords: six-port; reflectometer; radar; calibration; technique; displacement measurements

Improved Dual Six-Port Receiver Structure for Two-Dimensional Direction of Arrival Detection Using pHEMT Power Detectors - Mann, Sebastian; Vinci, Gabor; Lindner, Stefan; Barbon, Francesco; Linz, Sarah; Weigel, Robert; Kölpin, Alexander (IEEE European Radar Conference (EuRAD), 2013)
Abstract—Two-dimensional Direction Of Arrival detection (DOA) of an arbitrary electromagnetic wave is a challenging task, especially if high accuracy has to be performed. The proposed DOA receiver is based on a phase detector using the interferometric Six-Port principle. For the proposed system an improved power detector concept using a High Electron Mobility Transistor has been developed featuring strictly square law behaviour to at least -15 dBm. Thus, the system offers a high dynamic range of more than 40 dB. The hereby presented system concept additionally has a switched delay line phase shifter for frequency estimation of the incoming electromagnetic wave. Moreover, the most important system components have been validated by measurements.
elib2cris::1512001600,mann2013
Keywords: Six-Port; Direction-Of-Arrival; Phase measurement; Power Detector; pHEMT

Improved Indoor Semi-Static Human Target Detection and Localization using FMCW Radar - Kaiser, Kevin; Stadelmayer, Thomas; Felgentreff, Jens; Weigel, Robert; Lurz, Fabian; Santra, Avik (20th European Radar Conference, EuRAD 2023, 2023)
This paper presents a novel processing approach for semi-static human indoor perception and localization with Frequency modulated continuous wave (FMCW) radar. When analyzing semi-static targets with FMCW radar, minimal phase variations of standing or sitting human targets in slow-time can result in missed detections under traditional processing schemes. The common approach of studying micro-Doppler signatures over an extended period of time can, however, be costly in terms of both memory and compute resources. In this work, we introduce an approach with low memory and computational footprint, which relies on signatures beyond micro-Doppler for a novel presence score. We show on real-world recordings how this maximal variance based presence score can bring improvement in detection of static humans. To further increase detections in the range angle space, we introduce a novel angle of arrival estimation by creating a synthetic spatial signal from all phase differences between antennas over time. We show a 22.9% gain in human detection performance on a large dataset of humans in semi-static applications and highlight the reduction in computational complexity of both of these concepts.
CRIS-Team Scopus Importer:2023-12-01
Keywords: ceramics; coaxial resonators; delay filters; power amplifiers

Improved Initial Conditions for the Symmetrical Condensed TLM-Node with Respect to Physical Propagation Characteristics - Lindenmeier, Stefan; Isele, Bertram; Weigel, Robert; Russer, Peter (Progress in Electromagnetics Research Symposium, 1994)
elib2cris::1512001600,lindenmeier1994

Improved Mathematical Operations Based Calibration Method for Giant Magnetoresistive Current Sensor Applying B-Spline Modeling - Xie, Fei; Weiß, Roland; Weigel, Robert (Sensors and Actuators A-Physical, 2017)
Nowadays, giant magnetoresistance (GMR) based sensor technology is widely used in numerous industrial applications. However, an inexpensive and efficient method for compensating the nonlinearity of GMR spin valve sensor is still under the industrial expectation, which limits the applications of the GMR sensors. By applying the B-Spline modeling, excellent results were achieved; nevertheless, a calibration with several hundreds of measured data points over dozens of temperatures had to be conducted. In this paper an improved mathematical operations based calibration method for GMR spin valve type current sensors applying B-Spline modeling is introduced. This method allows a calibration for each further sensor applying B-Spline modeling with only two temperatures and per temperature only five measurement points. In comparison with the original calibration effort for B-Spline modeling, the new calibration method with minimized efforts showed an outstanding measurement accuracy of ±0.6% at a nominal current of 50 A in a temperature range from −20 °C to 80 °C. Due to the unexpected linear temperature behavior of the magnetic parameters, mainly of the uniaxial anisotropy to the exchange direction anisotropy ratio (Ku/Ked), only 5 measurement points at two different temperatures were necessary for our new calibration method.
elib2cris::1512001600,xie2016a
Keywords: Giant magnetoresistive (GMR); Current sensor; Current measurement; Sensor calibration; B -Spline modeling

Improved Modeling of Bulk Acoustic Wave Resonators and Filters - Hagelauer, Amelie Marietta; Link, Andreas; Bader, Bernhard; Marksteiner, Stefan; Wagner, Karl Christian; Weigel, Robert (IEEE International Ultrasonics Symposium 2010, 2010)
Duplexers and filters for mobile radio are one of the classic field of application for the BAW technology. In recent years the size of the devices has been reduced by about a half and the trend is still toward more compact designs with higher performance at the same time. This translates directly to very demanding requirements on the effective coupling coefficient and on the quality factors of the underlying BAW resonators. Measurements show that the size and the shape of the resonators have a significant influence on the overall performance. Hence, size-relevant effects need to be considered in ID-simulation, which is the base for fast filter optimization. To evaluate the influence of the resonator size on the filter performance we analyzed several SMR-BAW resonator area and shape variations in combination with different overlap sizes in a series of experiments. Moreover, the influence of the overlap size on different resonator areas is studied with 2D-FEM simulations. In this paper we present the results of our resonator measurements. The results are basis for developing a modified ID model for designing BAW filters. Additionally, a new method for the extraction of an 'equivalent acoustic impedance' for the description of the acoustics is presented and compared to the modified ID-model.
elib2cris::1512001600,hagelauer2010
Keywords: acoustic resonator filters; bulk acoustic wave devices; finite element analysis; 2D-FEM simulations; BAW filters; BAW technology; ID-simulation; SMR-BAW resonator; bulk acoustic wave resonators; effective coupling coefficient; equivalent acoustic impedance extraction; fast filter optimization; resonator measurements; resonator shape; resonator size; q-factor

Improved passive model for transient prediction of GaAs E/D MESFET analogue switches - Feng, Shen; Seitzer, Dieter (IEE Proceedings Circuits Devices and Systems, 1994)
An improved passive model of a GaAs MESFET is presented, where the intrinsic elements have a continuous dependence on gate, source and drain voltages for the benefit of transient prediction. Based on this passive model and circuit equations, the transient behaviour of analogue switches with GaAs E/D MESFETs is characterised with transfer time and transient error voltage in the lime domain. An analytical expression is derived for the transfer time calculation of symmetrical devices that explains the influence of parasitic and external resistances. The transient error voltage induced by clock feedthrough is calculated in the E/D MESFET switches with a general load. Load and parasitic capacitances reduce the voltage amplitude of transient errors induced by a transient breakthrough in the switches with a low impedance load, but they increase its transfer time. Good agreement is obtained between theoretical prediction and measurement on the transient breakthrough with 0.5 mum GaAs E/D MESFETs.
Keywords: SWITCHES AND SWITCHING THEORY; MODELING

Improved Performance in PMCW Radar Systems Through Equalization Using Predistortion and Postprocessing - Peters, Sebastian; Faghih-Naini, Samira; Weigel, Robert; Reißland, Torsten (2024 IEEE/MTT-S International Microwave Symposium, IMS 2024, 2024)
This work presents multiple concepts for spectral equalization in pulse-modulated continuous wave (PMCW) radar systems in order to restore the received signal for improved correlation results. Two concepts for postprocessing are presented which use the spillover signal for calibration. A third concept is introduced which uses a predistorted transmit signal and thus does not require spectral equalization in the receiver. The concepts are verified through measurements using a 60GHz transceiver together with digital-to-analog converters (DACs) and analog-to-digital converters (ADCs) operating at 4 GSa/s, resulting in a range resolution of under 4 cm.<br
https://cris.fau.de/converis/publicweb/Publication/318117060

Improved Target Detection and Feature Extraction using a Complex-Valued Adaptive Sinc Filter on Radar Time Domain Data - Stadelmayer, Thomas; Santra, Avik; Stadelmayer, Markus; Weigel, Robert; Lurz, Fabian (29TH EUROPEAN SIGNAL PROCESSING CONFERENCE (EUSIPCO 2021), 2021)
In state-of-art radar classification tasks the raw time domain ADC data is transformed to frequency domain wherein the target is detected. Feature data, such as the micro-Doppler signature, is extracted for classification of e.g. a performed gesture or a person based on its gait. However, the transformation into frequency domain using short-time Fourier transform resulting in erroneous target detection due to superposition of target components thus leading to sub-optimal feature for subsequent classification task. Thus, in this paper we propose a target feature extraction approach that operates directly on 2D time domain radar data by using a complex-valued adaptive 2D sine filter. The proposed approach tracks the target's slow-time and fast-time frequencies by a regulation loop, which progressively adjusts the filter's center frequency to the target location. We demonstrate that the proposed approach extracts better features in both single- and multi-target scenarios, leading to improved classification accuracy in gait classification problems using radars. Furthermore, the proposed time domain feature extraction approach facilitates the use of a parametric neural network that works directly on time domain data.<br
CRIS-Team WoS Importer:2022-04-22
Keywords: adaptive sinc filter; feature extraction; radar classification; time domain processing

Improved Target Detection and Feature Extraction using a Complex-Valued Adaptive Sinc Filter on Radar Time Domain Data - Stadelmayer, Thomas; Santra, Avik; Stadelmayer, Markus; Weigel, Robert; Lurz, Fabian (29th European Signal Processing Conference, 2021)
In state-of-art radar classification tasks the raw time domain ADC data is transformed to frequency domain wherein the target is detected. Feature data, such as the micro-Doppler signature, is extracted for classification of e.g. a performed gesture or a person based on its gait. However, the transformation into frequency domain using short-time Fourier transform resulting in erroneous target detection due to superposition of target components thus leading to sub-optimal feature for subsequent classification task. Thus, in this paper we propose a target feature extraction approach that operates directly on 2D time domain radar data by using a complex-valued adaptive 2D sine filter. The proposed approach tracks the target's slow-time and fast-time frequencies by a regulation loop, which progressively adjusts the filter's center frequency to the target location. We demonstrate that the proposed approach extracts better features in both single- and multi-target scenarios, leading to improved classification accuracy in gait classification problems using radars. Furthermore, the proposed time domain feature extraction approach facilitates the use of a parametric neural network that works directly on time domain dat

Improved time domain diffraction analysis for SAW transducers of arbitrary shape - Jungwirth, Mario; Greifeneder, Thomas; Scheiblhofer, Klaus; Stoegmueller, A.; Weigel, Robert; Malocha, Donald; Ruile, Werner; Ruppel, Clemens (IEEE Ultrasonics Symposium, 1999)
A time domain (TD) diffraction analysis for SAW transducers was previously developed based on Huygen's principle. The analysis was performed using an approximation to the scalar two dimensional impulse response of an ideal point source which allowed for fast computation of diffraction effects in the time domain. A more rigorous derivation of the TD impulse response from the frequency domain (FD) angular spectrum of waves (ASoW) approach for the case of isotropic phase velocity has also been previously presented, and the extension of the analysis to include the velocity and electromechanical coupling anisotropy found in typical SAW substrates was also included. In order to be able to use the FFT for fast computation an equidistant sampling in the time domain must be evaluated. The present paper will report on an improved resampling-algorithm with a particular weighting to obtain the required equidistant impulses in the time-response, to be able to use the Fast Fourier Transform. Arbitrary transducer geometries can be dealt with by our TD technique. Numerical simulation results (impulse and frequency responses) for specific geometries will be presented
elib2cris::1512001600,jungwirth1999a

Improvements of wireless communication and energy harvesting aspects for implantable sensor interfaces by using the Split Frequencies Concept - Walk, Jasmin; Ußmüller, Thomas; Weigel, Robert; Fischer, Georg (IEEE Radio and Wireless Symposium, 2011)
This work addresses system aspects of implantable medical sensor devices. Different concepts for power supply and communication are compared and discussed. State of the art systems mainly rely on one common frequency for both wireless data and energy transmission. This publication highlights the specific pros and cons of different frequency ranges. The proposed Split Frequencies Concept (SFC) uses two separate frequency bands: One for energy harvesting and the second for data transmission. Hence the advantages of HF and UHF frequencies can be combined into a single system. Index Terms IEEE Terms Antennas , Batteries , Data communication , Energy harvesting , Permittivity , Wireless communication , Wireless sensor networks INSPEC Controlled Indexing biomedical communication , biomedical electronics , biosensors , energy harvesting , health care , inductive power transmission , low-power electronics Non Controlled Indexing energy harvesting , energy transmission , implantable medical sensor devices , implantable sensor interfaces , split frequencies concept , wireless communication , wireless data transmission Author Keywords biological tissue , biomedical communication , biomedical power supplies , energy storage , frequency domain analysis , implantable biomedical devices , permittivity References R. Egeler, Statement von Praesident Roderich Egeler, Pressekonferenz Bevoelkerungsentwicklung in Deutschland bis 2060 am 18. November 2009 in Berlin, Statistisches Bundesamt Std., November 2009. 12th coordinated Population Projection, Statistisches Bundesamt 2009 Std. [Online]. Available: www.destatis.de/bevoelkerungspyramide M. Golombeck, C. Riedel, and O. Doessel, "Calculation of the dielectric properties of biological tissue using simple models of cell patches," Biomedizinische Technik/Biomedical Engineering, vol. 47, no. s1a, pp. 253-256, 2002. S. Chen and V. Thomas, "Optimization of inductive rfid technology," in Electronics and the Environment, 2001. Proceedings of the 2001 IEEE International Symposium on, 2001, pp. 82 -87. (Pubitemid 32882655) Abstract |Full Text: PDF (416KB) N. Chaimanonart and D. J. Young, "Remote rf powering system for wireless mems strain sensors," IEEE Sensors Jounal, vol. 6, no. 2, 2006. Abstract |Full Text: PDF (1912KB) C. Peng, W. H. Kong, and D. J. Young, "Wireless batteryless implantable blood pressure monitoring microsystem for small laboratory animals," IEEE Sensors Journal, vol. 10, no. 2, 2010. W. Greatbatch, J. H. Lee, W. Mathias, M. Eldridge, J. R. Moser, and A. A. Schneider, "The solid-state lithium battery: A new improved chemical power source for implantable cardiac pacemakers," IEEE J BME, no. 5, pp. 317-324, 1971. R. C. O'Handley, J. K. Huang, D. C. Bono, and J. Simon, "Improved wireless transcutaneouse power transmision for in vivo applications," IEEE Sensors Journal, vol. 8, no. 1, 2008. K. M. Silay, C. Dehollain, and M. Declercq, "Improvement of power efficiency of inductive links for implantable devices," in Proc. Ph.D. Research in Microelectronics and Electronics PRIME 2008, 2008, pp. 229-232. Abstract |Full Text: PDF (475KB) K. M. Silay, D. Dondi, L. Larcher, M. Declercq, L. Benini, Y. Leblebici, and C. Dehollain, "Load optimization of an inductive power link for remote powering of biomedical implants," in Proc. IEEE Int. Symp. Circuits and Systems ISCAS 2009, 2009, pp. 533-536. J. Essel, D. Brenk, J. Heidrich, H. Reinisch, G. Hofer, G. Holweg, and R. Weigel, "Highly efficient multistandard rfids enabling passive wireless sensing," in Proc. Asia Pacific Microwave Conf. APMC 2009, 2009, pp. 2228-2231. Abstract |Full Text: PDF (685KB) J. Essel, D. Brenk, J. Heidrich, and R. Weigel, "A highly efficient uhf rfid frontend approach," in Proc. IEEE MTT-S Int. Microwave Workshop Wireless Sensing, Local Positioning, and RFID IMWS 2009, 2009, pp. 1-4. E. Y. Chow, Y. Ouyang, B. Beier, W. J. Chappell, and P. P. Irazoqui, "Evaluation of cardiovascular stents as antennas for implantable wireless applications," IEEE Transactions on Microwave Theory and Techniques, vol. 57, no. 10, Oct. 2009. Abstract |Full Text: PDF (2020KB) P. Li, R. Bashirullah, and J. C. Principe, "A low power battery management system for rechargeable wireless implantable electronics," in Proc. IEEE Int. Symp. Circuits and Systems ISCAS 2006, 2006. H. Honda, K. Shiba, E. Shu, K. Koshiji, T. Murai, J. Yana, T. Masuzawa, E. Tatsumi, Y. Taenaka, and H. Takano, "Study on lithium-ion secondary battery for implantable artificial heart," in Proc. 19th Annual Int Engineering in Medicine and Biology Society Conf. of the IEEE, vol. 5, 1997, pp. 2315-2317. ON THIS PAGE Abstract Index Terms References Brought to you by Universitatsbibliothek Erlangen Nurnberg Your institute subscribes to: IEEE/IET Electronic Library (IEL), VDE VERLAG Conference Proceedings What can I access? Terms of Use
elib2cris::1512001600,walk2011

Improving GMR Current Sensor Measurements through Hysteresis Modelling - Jedlicska, Istvan; Weiß, Roland; Weigel, Robert (Power Electronics Specialists Conference (PESC 2008), 2008)
The measurement accuracy of GMR Current sensors suffers under the influence of hysteresis. For solving this problem, a hysteresis model has been implemented to keep track in real time of the sensor output signal. The model is a simplified version of the T(x) hysteresis model. Very good results have been achieved in comparing the software simulations and the real sensor characteristics. The model has been further implemented on a fixed-point Digital Signal Controller (DSC), connected to the sensor output. The linear output of the DSC confirmed the functioning of the model in the hardware implementation. An algorithm for eliminating error propagation during the measurements has been also developed.
elib2cris::1512001600,jedlicska2008

Impulsverhalten schneller Wanderwellen-Intensitaetsmodulatoren in LiNbO3 - Rodler, Hermann; Noll, Bernd; Weigel, Robert; Auracher, Franz (Proc. 2. Kolloquium Integrierte Optik der Deutschen Forschungsgemeinschaft, 1987)
null::1512001600,rodler1987

In CMOS integriertes Mehrantennen-Diversity-Empfangssystem für digitales Satellitenradio - Röber, Jürgen (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2016)

In-Containment Signal Conditioning and Transmission via Power Lines within High Dose Rate Areas of Nuclear Power Plants - Müller, Steffen; Dennerlein, Jürgen; Janke, Iryna; Weber, Johannes; Weigel, Robert; Kölpin, Alexander (4th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA), 2015)
Signal conditioning and transmission for sensor systems and networks within the containment of nuclear power plants (NPPs) still poses a challenge to engineers, particularly in the case of equipment upgrades for existing plants, temporary measurements, decommissioning of plants, but also for new builds. This paper presents an innovative method for efficient and cost-effective instrumentation within high dose rate areas inside the containment. A transmitter-receiver topology is proposed that allows simultaneous, unidirectional point-to-point transmission of multiple sensor signals by superimposing them on existing AC or DC power supply cables using power line communication (PLC) technology. Thereby the need for costly installation of additional cables and containment penetrations is eliminated. Based on commercial off-the-shelf (COTS) electronic parts, a radiation hard transmitter is designed to operate in harsh environment within the containment during full plant operation. Hardware modularity of the transmitter allows application specific tradeoffs between redundancy and channel bandwidth. At receiver side in non-radiated areas, signals are extracted from the power line, demodulated, and provided either in analog or digital output format. Laboratory qualification tests and field test results within a boiling water reactor (BWR) are validating the proof of concept of the proposed system.
elib2cris::1512001600,mueller2015a
Keywords: Power Line Communication; PLC; radiation hard electronics; radhard; sensor networks; online monitoring; OLM; monitoring and diagnostics; M&D

Increased Data Rate using Higher-order Digital Modulation for Simultaneous Inductive Data and Power Transfer Systems - Sanftl, Benedikt; Trautmann, Martin; Kleinhenz, Markus; Weigel, Robert; Kölpin, Alexander (IEEE MTT-S Wireless Power Transfer Conference 2017, 2017)
This paper presents an improved communication architecture with increased data rate for inductive power transfer (IPT) systems. The main challenge is to enable robust and reliable communication within the noisy environment of the power transfer. Therefore the communication channel, consisting of the coupled pair of coils of the inductive power transfer system is analysed. From this a frequency band with an excellent available signal to noise ratio was identified and is exploited using higher-order digital modulation schemes as n-th quadrature amplitude modulation or phase shift keying to increase the data rate. Furthermore the bandwidth of the system shall be extended by the utilisation of an equalizer. The implemented system using a software defined radio approach will be presented and it will be shown that reliable and fast communication is possible in this harsh environment.
Keywords: Inductive power transfer; inductive data communication; power filters; wireless communication; industrial electronics; digital modulation

Increased RF-Losses at the GaN/Si Interface after Eutectic Die Attach - Reiser, Korbinian; Twynam, John; Brech, Helmut; Hardikar, Shyam; Weigel, Robert (EuMIC 2019 - 2019 14th European Microwave Integrated Circuits Conference, 2019)
The influence of eutectic die attach on RF-substrate losses of AlGaN/GaN HEMTs grown on high-resistivity silicon substrates has been studied. A severe degradation in load pull efficiency is observed after die attach. Analyzing this degradation for dies attached to flanges with differing thermal expansion coefficient shows a linear relationship between substrate strain and load pull efficiency. Loss measurements of coplanar waveguides (CPWs) show increasing substrate losses with increasing strain, while the transistor on-resistance remains unaffected. The degradation in load pull efficiency is, therefore, attributed to increased substrate losses. By evaluating the bias dependence of low frequency capacitance measurements together with the bias dependence of CPW characteristics, we show that the increase in substrate loss can be explained by the formation of interface charge at the GaN/Si interface. To the best of our knowledge, this is the first time that GaN transistor efficiency degradation has been shown to correlate with transmission line losses and changes at the GaN/Si interface after eutectic die attach.
CRIS-Team Scopus Importer:2019-12-24
Keywords: CPW losses; die attach; Gallium nitride; GaN-on-Si; parasitic channel; power amplifiers; substrate losses

Increasing the Channel Capacity: Parallel Data Transmission in a Testbed for Molecular Communication - Bartunik, Max; Streb, Matthias; Unterweger, Harald; Haller, Jakob; Kirchner, Jens (NANOCOM '21: Proceedings of the Eight Annual ACM International Conference on Nanoscale Computing and Communication, 2021)
In the field of molecular communication, molecules or other parti-cles in the nanoscale are used to transmit information. This rather new communication paradigm has a large application potential,ranging from medicine to industrial systems. As testbeds are essential for evaluating the capabilities of this new form of communication, we improve an existing water-based testbed to achieve parallel data transmission within one communication channel in this work. To this end, two different information carriers, superparamagnetic iron oxide nanoparticles and fluorescent particles, are used to simultaneously transmit independent data streams. A detection system for fluorescent particles was specifically developed for the fluid molecular communication testbed. Using parallel data transmission in the modified testbed the channel capacity was nearly doubled in comparison to a transmission using only a single type of information particle
CRIS-Team Scopus Importer:2021-10-08
Keywords: molecular communication; fluorescence detection; nanoparticles; spions

Increasing the Measurement Accuracy of GMR Current Sensors through Hysteresis Modeling. - Jedlicska, Istvan; Weiß, Roland; Weigel, Robert (Industrial Electronics (ISIE 2008), 2008)
A method is presented for increasing the measurement accuracy of GMR (giant magnetoresistive) sensors by numerically eliminating the hysteresis in the output signal. A simplified mathematical model of the hysteresis has been derived from the T(x) hysteresis model for anticipating the measurement values. The model has been implemented in a software simulation environment and compared with real GMR sensor measurements, with very good results. Further, the model has been quantised and implemented on a fixed-point digital signal controller (DSC), connected to the output of the sensors. The linear output characteristic delivered in this case by the DSC confirmed the accuracy of the hysteresis model in the hardware implementation too. An algorithm based on the model has also been developed in order to eliminate error propagation during the measurements.
elib2cris::1512001600,jedlicska2008a

Indoor Positioning Utilizing Fractional-N PLL Synthesizer and Multi-Channel Base Stations - Gierlich, Roland; Hüttner, Jörg; Ziroff, Andreas; Huemer, Mario (European Wireless Technology Conference (EuWiT), 2008)
An indoor positioning system operating in the 5.8 GHz ISM-band is presented. The system principle is based on time-difference of arrival (TDoA) measurements by means of frequency modulated continuous wave (FMCW) signals. We briefly outline the measurement principle and system topology. Furthermore, we present a localizable tag hardware that features a novel integrated fractional-N PLL synthesizer for frequency ramp generation. The synthesizer IC has been designed within the Resolution project with the objective of low-power and inexpensive signal generation. The second focus of this paper is on measurement results that have been obtained using the integrated synthesizer in combination with a 4-channel base station. Due to the constricted signal bandwidth of 150 MHz, multipath propagation sets tight limits on ranging accuracy. By application of digital beam-forming techniques on the infrastructure side, we could significantly decrease the impact of channel echoes on accuracy compared with conventional single-channel systems.
elib2cris::1512001600,gierlich2008

Inductive transcutaneous energy transfer for cardiac assist devices – pushing the limits - Kirchner, Jens; Ebel, Nina; Kinner, Sarah; Fischer, Georg; Werner, Siegfried; Schubert, Dirk W.; Weyand, Michael (22. Chirurgische Forschungstage, 2018)
Background / Purpose Power supply is an essential component of active implants. To provide energy across the skin barrier, inductive energy transfer is well established in low-power devices like Cochlea implants. However, current designs are not applicable to high-power implants like cardiac assist devices due to strong tissue heating, caused by local spots of high magnetic field strength associated with large heat dissipation. Here, we propose a system design that overcomes this problem. Methods To avoid the “hot spots”, the magnetic field is guided and thus homogenized by composite coil cores based on liquid silicon rubber (LSM), which permits to design appropriate gradients of permeability. Furthermore, the frequency is kept below 1 MHz to reduce dielectric losses within the body. LSM is a biocompatible material, whose flexibility allows adaption to the body surface to minimize the gap between extracorporeal and implanted coil. For analysis and optimization of coil and coil core design, the FEM software COMSOL Multiphysics® 5.3 was used. Results The simulations showed that with the proposed coil and coil core design the magnetic fields can be homogenized such that 24 W can be transferred with an efficiency of 98.8% and a temperature increase in the tissue of only 0.8°C. Conclusions These findings suggest the possibility to make inductive energy transfer applicable also for high‑power active implants such as ventricular assist devices, reducing the number of complications of VAD-patients.
Keywords: Inductive energy transfer; transcutaneous energy transfer; cardiac assist device

Inductor Design Flow for Microwave and Radio Frequency Integrated Circuits - Kitlinski, Krzysztof; Büyüktas, K.; Monteil-Montaya, R.; Weigel, Robert (DAC 2005, 2005)
elib2cris::1512001600,kitlinski2005
Keywords: Inductor

Inductor Design Flow for Microwave Integrated Power Amplifiers - Kitlinski, Krzysztof; Büyüktas, K.; Monteil-Montaya, R.; Weigel, Robert (13th Conference on Microwave Techniques (COMITE), 2005)
elib2cris::1512001600,kitlinski2005b
Keywords: Inductor

Induktive Energie- und Datenübertragung - Lindner, Stefan (2010)
elib2cris::1512001600,lindner2010

Industrial mmWave Radar Sensor in Embedded Wafer-Level BGA Packaging Technology - Beck, Christopher; Ng, Herman Jalli; Agethen, Roman; Pour Mousavi, Seyed Mehran; Forstner, Hans-Peter; Wojnowski, Maciej; Pressel, Klaus; Weigel, Robert; Hagelauer, Amelie Marietta; Kissinger, Dietmar (IEEE Sensors Journal, 2016)
We present highly integrated 60GHz radar transceivers for industrial sensor applications. The bistatic and monostatic transceivers are implemented in the SiGe bipolar technology and packaged using the embedded wafer-level ball grid array (eWLB) technology that allows for direct embedding of the antennas in the package redistribution layer. In this way, very compact and efficient radar frontends comprising all millimeter-wave components can be implemented in an 8 × 8mm2 package. These frontends were soldered on a standard low-cost PCB based on FR4 material. For verification of the proposed frontends, an FMCW radar system was developed and set up within this work. Theoretical considerations and simulations as well as corresponding measurements were carried out for the evaluation of the designed system. The demonstrator results of these embedded radar sensors show excellent system performance at a high integration level.
elib2cris::1512001600,beck2016
Keywords: SiGe RFICs; SiP modules; millimeter-wave circuits; packaging; radar systems

Industrial Modal Analysis: Measuring Vibrations in Harsh Environments by Six-Port Technology - Kölpin, Alexander (Radar, Communication and Measurement (RADCOM), 2013)
elib2cris::1512001600,koelpin2013
Keywords: Six-Port; Vibration

In ein Autodach integrierbare adaptive Schlitzantenne für mobile Kommunikation - Fischer, Georg (ITG Fachberichte 128, VDE Verlag, 1994)
Keywords: Mobile Communication; Slot antenna

Influence of accurate electron drift velocity modelling on the electrical characteristics in gan-on-si hemts - Reiser, Korbinian; Twynam, John; Eckl, Christian; Brech, Helmut; Weigel, Robert (International Conference on Simulation of Semiconductor Processes and Devices, SISPAD, 2019)
The influence of an accurate electron velocity-field relationship modelling on pulsed IV and small-signal RF characteristics in GaN-on-Si HEMTs is discussed and compared to measurements. We show by technology computer-Aided design (TCAD) simulation and measurements that not only the lowfield mobility and saturation velocity are of great importance, but also the transition behaviour in between has to be modelled accurately. Experimentally, we extract the velocity-field relationship using device simulation and measured data with ultra short pulse lengths. To the best of our knowledge, this is the first study on the velocity-field relationship in GaN-on-Si devices.
CRIS-Team Scopus Importer:2019-11-12
Keywords: Gallium nitride; GaN-on-Si; saturation velocity; TCAD; velocity field curve

Influence of Dissipated Power Distribution on BAW Resonators - Tag, Andreas; Karolewski, Dominik; Bader, Bernhard; Pitschi, Maximilian; Weigel, Robert; Hagelauer, Amelie Marietta (2014 IEEE International Ultrasonics Symposium, 2014)
Background, Motivation and Objective: Bulk Acoustic Wave (BAW) filters and Duplexers are often used at high power levels at which the temperature of the device increases due to power dissipation (self-heating) resulting in turn in significant frequency shifts of the transfer function of the device. This behavior needs to be modeled accurately to be able to design devices working appropriately at these power levels. Statement of Contribution/Methods: Simulations with coupled electromagnetic (EM) acoustic thermal 3D finite element methods (FEM) require tremendously high calculation times. The solutions presented in the literature are based on a measured TCF and dissipated power calculated from S-parameters. That means neither the distribution of temperature nor the distribution of the dissipated power are considered. In our previously work, we have shown that the modeling of the frequency shifts caused by the self-heating behavior can be improved by taking the spatial temperature distribution into account. In this work, it will be shown for the first time that the spatial distribution of dissipated power considerably influence the temperature level and temperature distribution. Therefore, it has to be taken into account in order precisely model the BAW self-heating behavior. Results, Discussion and Conclusions: The acoustic was modeled in one dimension allowing efficient calculation times. EM has been modeled with a 3D FEM simulation program. From the obtained strain distribution along the different layers of the resonator (an example is shown in Fig. 1) the spatial distribution of viscous losses along the different layers was calculated and transferred to the thermal 3D simulation. The remaining main losses (eddy currents, redistribution currents, resistivity losses, and dielectric losses) were applied to the electrodes and piezoelectric layer. The result of the thermal simulation was the spatial temperature distribution over the device geometry. This temperature distribution was used to modify the geometry of the resonator and the materials for the EM and acoustic simulations. Finally, the acoustic and EM simulations were repeated with all the modifications providing the behavior of the resonator at high power level. By the extension of the modeling approach remarkable improvements (some tens of percents) in the modeling of the temperature level and the resonator transfer function frequency shifts have been achieved.
elib2cris::1512001600,tag2014b

Influence of linear and non-linear distortions in SAW/FBAR duplexers for 3rd generation mobile phone systems - Tsutsumi, Jun; Inoue, Shogo; Ueda, Manasori; Weigel, Robert (Proceedings of the European Microwave Association, 2007)
elib2cris::1512001600,tsutsumi2007

Influence of Loss Mechanisms on High Q Whispering Gallery Mode (WGM) Resonators suitable for RF Applications - Silva Cortes, Victor Arturo; Binder, Jonathan; Fischer, Georg; Hagelauer, Amelie Marietta (IEEE Electrical Design of Advanced Packaging and Systems Symposium, 2017)

Influence of Mobile Charges in the Substrate of BAW Filters on High Resistivity Silicon. - Hagelauer, Amelie Marietta; Bader, Bernhard; Henn, G.; Schaeufele, A.; Marksteiner, Stefan; Wagner, Karl Christian; Weigel, Robert (International Ultrasonics Symposium, 2009)
BAW (bulk acoustic wave) filters have emerged as an important technology for GHz filtering components. Especially the high quality factor and the good temperature coefficient make BAW filters well suited for W-CDMA band 2 and band 3 devices. During the design phase it is essential to analyze and minimize possible loss mechanisms to meet the high requirements of these devices. Well known loss mechanisms are metal conductivity, viscosity and acoustic losses. A less well known loss mechanism is the existence of mobile charges at the surface of high resistivity silicon. This loss effect appears between the silicon substrate and the first silicon dioxide layer of the BAW structure. Induced charges increase the insertion loss and influence the performance of BAW filters. The two methods that are most promising for BAW applications to minimize the effect are ion implantation and the use of low charge silicon-dioxide. The aim of this work is the investigation and comparison of the mentioned methods in case of mirror-type BAW filters. We describe the loss mechanism, its counter measures and the impact on the filter performance. Therefore we designed test filters and test structures, manufactured on several test wafers. Additionally we used EM-simulations to evaluate the measurements of our test structures. An extended filter simulation model reflects the measured insertion attenuation of the filter performance pretty well.
elib2cris::1512001600,hagelauer2009a
Keywords: BAW filter substrate; EM-simulations; GHz filtering components; W-CDMA band 2 devices; W-CDMA band 3 devices; bulk acoustic wave filters; extended filter simulation model; first silicon dioxide layer; high resistivity silicon; induced charges; insertion attenuation; insertion loss; ion implantation; loss mechanisms; low charge silicon dioxid; mirror-type BAW filters; silicon substrate; surface mobile charges; bulk acoustic wave devices; code division multiple access; dielectric losses; elemental semiconductors; radiofrequency filters; silicon; substrates; surface acoustic wave filters; surface charging

Influence of parasitic modes in SAW resonators on the measurement accuracy of wireless time domain sampling readers - Lurz, Fabian; Hagelauer, Amelie (SAW Sensor & Actuator Symposium, 2021)

Influence of Receiver Front End Nonlineartities on W-CDMA Signals - Maurer, Linus; Schelmbauer, Werner; Pretl, Harald; Springer, Andreas; Adler, Bernd; Boos, Zdravko; Weigel, Robert (Asia-Pacific Microwave Conference, 2000)
elib2cris::1512001600,maurer2000b

Influence of Self-Interference in a Radar System for a Correlation Based True-Speed-Over-Ground Estimation Approach - Reißland, Torsten; Michler, Fabian; Weigel, Robert; Koelpin, Alexander; Lurz, Fabian (2022 IEEE Topical Conference on Wireless Sensors and Sensor Networks, WiSNeT 2022, 2022)
In this paper we present an experimental examination on the influence of self-interference in a true-speed-overground measurement system. The setup is based on two antenna pairs, in which interference is to be expected if they transmit simultaneously. This work compares the estimation results for simultaneous and for time division multiplexed transmission. Furthermore, an approach for the decoupling of the receive channels is introduced and examined.
CRIS-Team Scopus Importer:2022-04-15
Keywords: correlation; interference; radar; rail transportation; velocity measurement

Influence of Temperature Distribution on Behavior, Modeling, and Reliability of BAW Resonators - Tag, Andreas; Karolewski, Dominik; Huck, Christian; Bader, Bernhard; Pitschi, Maximilian; Wagner, W.; Schäffel, Christoph; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE International Reliability Physics Symposium, 2014)
elib2cris::1512001600,tag2014

Influence of the Conductor Position on a Circular Array of Hall Sensors for Current Measurement - Itzke, Alexander; Weiss, Roland; Weigel, Robert (IEEE Transactions on Industrial Electronics, 2018)

Influence of the PCB Manufacturing Process on the Measurement Error of Planar Relative Permittivity Sensors Up To 100 GHz - Lau, Isabella; Hajian, Ali; Michler, Fabian; Gold, Gerald; Lurz, Fabian; Schmid, Ulrich; Helmreich, Klaus; Weigel, Robert; Kölpin, Alexander (IEEE Transactions on Microwave Theory and Techniques, 2019)
Accurate and precise knowledge of the relative permittivity of printed circuit board (PCB) materials is essential for the reliable design of high-frequency circuits. For simplicity reasons, planar, resonant permittivity sensors, which are directly integrated on the unknown PCB material, are widely used. However, the sensors are affected by the nonidealities of the copper-clad laminate and PCB manufacturing process, e.g., the difference in roughness between the top and bottom sides of each metal layer. This paper analyzes the influence of these nonidealities on the extracted relative permittivity values of different sensor geometries in microstrip and substrate integrated waveguide (SIW) technology up to 100 GHz. Microstrip resonators are very sensitive against the investigated nonidealities. Additional roughness measurements and more detailed simulation models cannot noticeably reduce the uncertainties. SIW cavity sensors are more robust, and simple modeling approaches lead to low uncertainties smaller than 0.05 for the whole frequency range from 10 to 100 GH
Keywords: Accuracy; manufacturingn process; materials nondestructive testing; microwave measurements; permittivity; printed circuit boards (PCBs); surface roughness; uncertainty.

Influence of Train Interior on Train-Onboard Communication - Lichtblau, Johann; Sanftl, Benedikt; Kraus, Christian; Weigel, Robert; Kölpin, Alexander (22nd International Microwave and Radar Conference (MIKON), 2018)

Influencing Cell Reselection of UMTS User Equipment using Interference Injection - Gardill, Markus; Zorn, Stefan; Weigel, Robert; Kölpin, Alexander (RadCom, 2011)
elib2cris::1512001600,gardill2011a