A different look on cyclic prefix for SC/FDE - Witschnig, Harald; Mayer, Thomas; Springer, Andreas; Koppler, Alois; Maurer, Linus; Huemer, Mario; Weigel, Robert (The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2002)
We investigate the use of a known symbol sequence - a so-called unique word (UW) - instead of the well-known cyclic prefix (as it is used in OFDM, orthogonal frequency division multiplexing, systems) for a single carrier system with frequency domain equalization (SC/FDE). The considered SC/FDE system is similar to the one proposed in the IEEE 802.16.3c target group. It is shown that the UW fulfils the theorem of cyclic convolution required for efficient implementation of the SC/FDE structure. We elaborate on the advantages that result for equalization, channel estimation, and synchronisation. Compared to the advantages, the disadvantages in terms of BER behaviour and bandwidth efficiency are rather modest.
elib2cris::1512001600,witschnig2002d

A Digital Adaptive Feedback Loop for Local Oscillator Leakage Cancellation and DC Offset Compensation - Lanschützer, Christian; Springer, Andreas; Maurer, Linus; Boos, Zdravko; Weigel, Robert (Asia Pacific Microwave Conference, 2002)
elib2cris::1512001600,lanschuetzer2002a

A Digital Adjustable 60-GHz Integrated Sixport Receiver Front-End in a 130-nm BiCMOS Technology - Völkel, Matthias; Weigel, Robert; Hagelauer, Amelie Marietta (RWW, 2019)
In this paper, a fully integrated digital adjustable sixport receiver front-end working at 60GHz is presented. The circuit features two variable gain amplifier, the passive sixport network, four detectors and a SPI-interface. Application area are industrial radar or angle of arrival detection. The phase measurement is done by superposition and power detection of two millimeter wave signals. The integrated circuit has a power consumption of 88.44mW from a 3.3V supply voltage. It is fabricated in a 0.13μm SiGe BiCMOS process and has a size of 1560μm x 1000 μm. The RF and reference input power can be adjusted in a 21 dB range over a 12 bit digital interface. The receiver exhibits a 1 dB compression point of -21.9 dB. RF signals down to -55dBm are detectable.<br
Keywords: angle of arrival; industrial radar; interferometer; phase measurement; SiGe BiCMOS; sixport

A Digital Adjustable Fully Integrated Bistatic Interferometric Radar Transceiver at 60 GHz in a 130 nm BiCMOS Technology - Völkel, Matthias; Dietz, Marco; Hagelauer, Amelie Marietta; Hussein, E. M.; Kissinger, Dietmar; Weigel, Robert (EUMW, 2019)
In this paper a 60 GHz monolithic bistatic interferometric radar transceiver for high precision measuring is presented. The integrated transceiver has been designed using a 0.13μm SiGe BiCMOS process from IHP (SG13G2) and includes a LNA, a passive six-port structure, detectors, multiplier, multiplexer, power amplifier and a digital interface. The chip has a size of 2330μm x 1360μm and a maximum power consumption of 533mW from a 3.3V power supply. The circuit provides two frequency inputs of 7.5 and 15GHz and multiplies them up to 60 GHz at a minimum input power of -20 dBm. The chip delivers a maximum output power of 9dBm at 61 GHz. The input path is selectable and the output power is adjustable by a digital interface between -23 and 9dBm at 60 GHz. Also the reference input power of the six-port and the RF input power can be adjusted in a range of 13.2 dB. The minimum input referred P1dB is -24.1 dBm. With a multiplexer, the receiver reference can be separated from the transmitter, which allows the use of both independently from each other. The serial interface is realized in 0.13μm CMOS logic and consists of a 20 bit shift register, decoder and an analog interface.<br
Keywords: bistatic radar; digital adjustable; industrial radar; integrated transceiver; interferometric radar; millimeter wave circuits; SiGe BiCMOS; six-port

A Digital Correction Method for Increased Dynamic Range in Interferometric Six-Port Radars - Krause, Sascha; Michler, Fabian; Kölpin, Alexander; Rudolph, Matthias; Heinrich, Wolfgang (IEEE Microwave and Wireless Components Letters, 2021)
In this paper, we demonstrate a digital correction method for extending the dynamic range of a six-port radar system based on detector diodes. An individual diode gain is considered to depend on output voltage, which can be approximated as a linear function in order to extrapolate the diode's square-law response to higher input powers. The individual diode coefficients are extracted during an initial calibration measurement utilizing the interferometric working principle. A six-port junction in combination with power detectors based on Si Schottky diodes operating at 24GHz has been employed to validate the concept. Reduction of the 3rd-and 5th-order harmonic of up to 35dB and 22dB, respectively, have been achieved at the highest input power of 8dBm. The correction was applied for a wide range of operating conditions. As a result, the increase of phase error under large-signal and high power operation is effectively compensated and remains as low as under small-signal conditions. Thus, phase accuracy is maintained beyond the classical dynamic range of detector diodes in six-port applications so far.<br

A Digital Front-End Supported Frequency Agile Multi-Standard Wireless Receiver - Maurer, Linus; Burger, Thomas; Dellsperger, Thomas; Stuhlberger, Rainer; Hueber, Gernot; Schmidt, Matthias; Weigel, Robert (Frequenz, 2005)
This paper presents a flexible multi-standard receiver architecture that extends the well known direct conversion receiver (DCR). With high dynamic-range/low-power sigma-delta analog-to-digital converters (ADC) and digital signal processing functions locally on the radio frequency integrated circuit (RFIC) a receiver with relaxed requirements for the analog part and a variable bandwidth channel filtering in the digital domain can be realized. Since analog building blocks have limited reconfiguration capabilities by nature of their implementation, the extension of the conventional analog signal processing blocks by a digital front-end (DFE) greatly enhances the flexibility of the RFIC. Key building blocks for the proposed receiver architecture, such as tunable RF filters, ADC and digital filters are discussed.
elib2cris::1512001600,maurer2005

A Digitally Controlled D-Band Phase Shifter for FMCW Radar and RadCom in SiGe BiCMOS - Schrotz, Albert-Marcel; Breun, Sascha; Schönhärl, Stefan; Weigel, Robert (2024)
https://cris.fau.de/converis/publicweb/Publication/319893554

A Digital Platform for a Multichannel Digital Wideband Scanning Receiver - Langmann, Frank; Mzyk, Raphael; Dehm-Andone, Gunther; Fischer, Georg; Weigel, Robert (7th Karlsruhe Workshop on Software Radios, 2012)
elib2cris::1512001600,hausknecht2012
Keywords: Digital; Platform; Multichannel; Scanning; Receiver; Architecture

A Digital Power Amplifier in 28 nm CMOS for LTE Applications - Fuhrmann, Jörg (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2016)

A digital trimmable comparator for high precision ADCs in wireless sensor nodes - Jung, Melanie; Ferizi, Alban; Ußmüller, Thomas; Fischer, Georg; Weigel, Robert (Semiconductor Conference Dresden, 2011)
elib2cris::1512001600,jung2011b

A Direction-of-Arrival Estimation System for UAV-Assisted Search and Rescue: Locating Mobile Phones to Improve the Survival Chance of Disaster Victims - Depold, Andreas; Dorn, Christian; Erhardt, Stefan; Weigel, Robert; Lurz, Fabian (IEEE Microwave Magazine, 2023)
Collapsing buildings are, while not exactly common, still an issue. The causes are diverse and often region dependent. The most common cause of the large-scale structural failure of buildings is earthquakes. In countries less affected by earthquakes, explosions caused by gas leaks are the leading cause.
CRIS-Team Scopus Importer:2023-03-03

A Direct RF-to-Baseband Quadrature Subsampling Receiver Using a Low Cost ADC - Haberl, Matthias; Sanftl, Benedikt; Trautmann, Martin; Weigel, Robert; Kölpin, Alexander (2017 IEEE Radio and Wireless Symposium (RWS), 2017)
This paper presents a novel receiver using direct complex subsampling. In this approach no frequency conversion is used, but therefore bandpass sampling in combination with nonuniform sampling. A special sampling pattern for the analog to digital conversion is used. The resulting sampling frequency is below the carrier frequency, like in standard bandpass sampling receivers. Therefore the requirements for the analog-digital converter (ADC) and digital signal processor (DSP) are decreased. The sample and hold stage of the ADC still has to meet the requirements for the carrier frequency. The corresponding sampling scheme and its signal processing are described. A simulation of a QPSK receiver is presented. The proposed architecture is validated using a low cost commercial-off-the-shelf (COTS) ADC along with some testing and measurements. The receiver works for the industrial, scientific and medical band (ISM) carrier frequency at 13.56 MHz, which is commonly used for short range devices like radio-frequency identification (RFID) applications.
elib2cris::1512001600,haberl2017
Keywords: ADC; I/Q signal processing; nonuniform sampling; subsampling

A Distributed RC Power Supply System for Low EME ICs - Kruppa, Jack (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2010)

A Downconversion Link for a 5G Repeater using a Passive Power Adjustment Technique and Analog Predistortion - Potschka, Julian; Kolb, Katharina; Maiwald, Tim; Dietz, Marco; Hagelauer, Amelie; Aufinger, Klaus; Weigel, Robert (IEEE European Microwave Conference, 2021)

A Dual-Channel 15 Gb/s PRBS Generator for a D-Band PMCW Radar Transmitter in 22 nm FDSOI - Probst, Florian; Engelmann, Andre; Koch, Manuel; Weigel, Robert (IEEE Wireless and Microwave Technology Conference, WAMICON 2023, 2023)
This work proposes an integrated baseband signal generator with multiple orthogonal outputs for phase-modulated continuous-wave (PMCW) radar. The circuit combines a linear-feedback shift register (LFSR), producing an m-sequence at a chip rate of 15 Gb/s, with a digitally implemented outer code (OC) generator. Different channels can be distinguished at the receiver through a slow-time modulation of the pseudo-random binary sequence (PRBS) with different Hadamard codes. The generator is integrated into a 1700×1300 μm² double-channel D-band radar transmitter on a 22nm fully-depleted silicon on insulator (FDSOI) technology, of which only 73×80 μm² are devoted to the baseband generator. A measurement setup is presented, where the transmitter’s D-band output signal is externally down-converted and sampled using a high-speed oscilloscope. In a series of offline digital signal processing (DSP) steps including correlation, accumulation and another correlation, the functionality of the proposed generator is demonstrated.<br
Keywords: Fully-depleted silicon on insulator (FDSOI); MIMO radar; phase-modulated continuous-wave (PMCW); joint radar-communication (RadCom); true single-phase-clock (TSPC)

Advanced Audio Measurement System using Psychoacoustic Properties - Herre, Jürgen; Eberlein, Ernst; Schott, Hartmut; Brandenburg, Karlheinz (AES, 1992)
Vorträge und Veröffentlichungen auf Konferenzen_subjektive Audioqualität

Advanced Characterisation of a Sensor System for Droplet-Based Microfluidics - Bartunik, Max; Fleischer, Marco; Haselmayr, Werner; Kirchner, Jens (2020 IEEE Sensors, 2020)

Advanced In-Situ Instrumentation of RF Circuits for Mixed-Field Irradiation Testing Purpose - Müller, Steffen; Danzeca, Salvatore; Garcia Alía, Rubén; Brugger, Markus; Weigel, Robert; Kölpin, Alexander (European Conference on Radiation and its Effects on Components and Systems (RADECS), 2017)

Advanced Millimeter-Wave FMCW Radar System Simulations for Automotive Applications - Weigel, Robert; Dudek, Manuel (Electrical and Electronic Engineering for Communication Workshop - Entwicklerforum - Fachmesse, 2011)
elib2cris::1512001600,weigel2011b

Advanced receiver testing in a high volume environment using pogo cross-talk a case study - Fuchs, Stephan; Weigel, Robert (German Microwave Conference, 2016)
More and more frequency bands as well as receiver ports are integrated in a single silicon device. This is caused by the rapid development of cellular technologies towards highly integrated multimode transceivers capable of worldwide interoperability in multiple frequency bands. For ensuring highest quality standards in customer delivery, accurate testing and characterization of all these ports is essential. However, the high volume testing becomes increasingly more time consuming due to the number of ports and the respective tester interface PCB (printed circuit board) design. This paper demonstrates a feasible way to increase throughput by higher multisite efficiency with sharing one internal RF-source by using pogo cross-talk.
elib2cris::1512001600,fuchs2016

Advanced simulations of automotive EMC measurement setups using stochastic cable bundle models - Gonser, Markus; Keller, Christian; Hansen, Jan; Weigel, Robert (Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC), 2010, 2010)
This paper deals with modeling and simulation of cable bundles for automotive EMC tests. A new stochastic cable bundle model is presented. The parameters of the model are grouped into parameters for geometry, simulation, and disorder. Using a particularly developed cable bundle testbench, the model is validated against measurements and the parameter dependencies are investigated. The parameter study shows that the model is governed by one universal constant which describes the stochastics of the cable bundle and a characteristic density which is directly related to the cable bundle geometry. Finally, the model is used in an exemplary EMC setup whose device under test is a partially populated printed circuit board of an automotive electronic control unit. The simulation agrees very well with the according real life measurement setup.
elib2cris::1512001600,gonser2010a
Keywords: Automotive electronics; Automotive engineering; Circuit testing; Electromagnetic compatibility; Electronic equipment testing; Particle measurements; Printed circuits; Solid modeling; Stochastic processes

Advanced Template Matching Algorithm for Instantaneous Heartbeat Detection using Continuous Wave Radar Systems - Will, Christoph; Shi, Kilin; Weigel, Robert; Kölpin, Alexander (IEEE MTT-S International Microwave Bio Conference (IMBioC), 2017)
Instantaneous heartbeat detection is a key parameter in modern vital sign monitoring. Continuous wave (CW) radar systems enable contactless measurements of the vibrations on the human skin effected by heartbeats. Since a high accuracy as well as robustness of the measurement sensor is appreciated, the belonging signal processing routine has to deal with challenging requirements. In this paper, an advanced template matching (ATM) algorithm is proposed to enhance the performance regarding instantaneous heartbeat detection using CW radar systems. Compared to common template matching algorithms, multiple heterogeneous templates are utilized in this approach, at which the appropriate template type is determined by prior feature detection. A 24 Ghz Six-Port microwave interferometer is used for vital sign measurements of a person-under-test. The functionality of the proposed algorithm is verified by a synchronous reference electrocardiogram (ECG) and its enhancement is shown by reducing the root-mean-square error (RMSE) of the interbeat intervals (IBI) compared to an ordinary template matching algorithm.

Advanced transmitters with combined crest factor reduction and digital predistortion techniques - Farabegoli, Alessio; Sogl, Bernhard; Müller, Jan-Erik; Weigel, Robert (Radio and Wireless Symposium (RWS), 2014 IEEE, 2014)

Advances in GaN-based discrete power devices for L- and X-band applications - Fischer, Georg; Würfl, Hans-Joachim; Behtash, R.; Richard, l.; Liero, A.; Heinrich, Wolfgang; Tränkle, G.; Hirche, K. (European Microwave Week, 2006)
Progress in fabrication of packaged discrete L- and X-band power AlGaN/GaN HFETs is presented. By exploiting typical GaN HFET related features such as improved linearity, power density, gain and broad band capability the devices allow for novel architectures for base stations in mobile communications and for space applications. Highlights to be presented are L-band power bar devices designed for continuous wave (cw) operation delivering an cw output power of 30 W and 100 W with 20 dB and 14 dB linear gain respectively. The architecture of these devices is based on novel gate "feed plate" structures. Furthermore discrete, hermetically packaged X-band devices for space based SSPAs in the power range of 10 W (continuous wave) at 8 GHz are presented.
elib2cris::1512001600,fischer2006f
Keywords: Gallium nitride; discrete; power bars; power amplifiers

A Fall Detection and Activity Monitoring Algorithm for a Tele-Care System Supporting Dementia and Alzheimer Patients - Schwarzmeier, Andre; Roth, Nils; Weigel, Robert; Fischer, Georg; Kissinger, Dietmar (BMT 2014 - 48. Jahrestagung der DGBMT, 2014)
Dementia and Alzheimer patients who show a “wandering” behaviour combined with excessive activity and unsteady gait are exposed to a particular risk of dangerous falls. Fast and efficient help in case of such an emergency could be provided by a tele-care system comprising a mobile back-plaster as an on-body sensor node that is equipped with sen-sors which not only capture activity and movement data from the patient but also enable indoor and outdoor localiza-tion. This node is linked to an internet server infrastructure including a back-end software. In order to enhance the care quality reliable algorithms for activity monitoring and fall detection are needed.
elib2cris::1512001600,schwarzmeier2014a

A Fast and Precise Six-Port-based IFM Technique for Wireless Resonant SAW Sensing - Weigel, Robert; Lurz, Fabian; Lindner, Stefan; Mann, Sebastian; Linz, Sarah; Kölpin, Alexander (IEEE International Ultrasonics Symposium (IUS), 2016)
elib2cris::1512001600,weigel2016a

A fast general purpose CPU utilizing signed-digit encoding and multi-bit memristors - Wust, Daniel; Söll, Christopher; Fey, Dietmar (HiPEAC Workshop on Memristor Technology, Design, Automation and Computing, 2017)
-
elib2cris::1512001600,wust2017

A fast spatial domain method for the suppression of excitation-induced spurious modes in SCN-TLM - Lindenmeier, Stefan; Isele, Bertram; Weigel, Robert; Russer, Peter (IEEE MTT-S International Microwave Symposium Digest, 1996)
A fast method for the suppression of excitation-induced spurious modes in the Transmission Line Matrix (TLM) method is presented for the symmetrical condensed node (SCN) scheme. The method of spurious-free excitation allows for a coarser mesh discretization improving the effectiveness of the TLM-simulation. The capability of the method is demonstrated by way of an example.
elib2cris::1512001600,lindenmeier1996

A fast spatial-domain method for the suppression of excitation-induced spurious modes in SCN TLM - Lindenmeier, Stefan; Isele, Bertram; Weigel, Robert; Russer, Peter (IEEE Transactions on Microwave Theory and Techniques, 1997)
An efficient method for the suppression of excitation-induced spurious modes in the symmetrical condensed node (SCN) transmission-line matrix (TLM) method is presented for the general case of dielectric, anisotropic, or lossy media in planar structures. A special mapping of the field-excitation onto the wave amplitudes of the TLM algorithm completely prevents the emanation of the spurious modes. The application of the mapping in the k-ω space can be done for waveguides with low computational effort. The method is generalized for planar structures with high spatial frequencies of the field at the discontinuities. We use precomputed field templates at the entrance of the three-dimensional (3-D) structures. The mapping is mainly done in the space domain based on the quasi-TEM propagation of the guided waves to keep the computational effort low. Instead of the four-dimensional (4-D) k-ω transformation, only independent one-dimensional (1-D) transformations to the wave coefficient of the conductors direction and ω are necessary. In the case of propagation with low dispersion, the expenditure can be further reduced to 1-D transformations with respect to ω. The efficiency of the present method is demonstrated by investigation of a coplanar waveguide and a triplate waveguide
elib2cris::1512001600,lindenmeier1997
Keywords: Excitation; spurious modes; TLM

A Ferroelectric Tunable Combline Filter With Improved Stopband Transitions - Lourandakis, Errikos; Schmidt, Matthias; Fischer, Georg; Weigel, Robert (Radio and Wireless Symposium, 2009. RWS '09. IEEE, 2009)
In this work the design of a microstrip line based frequency agile bandpass filter with improved selectivity is presented. The original combline bandpass performance is improved, by a transmission zero which is inserted in the lower stopband, resulting in steeper stopband transitions. The frequency agile behavior is obtained by using ferroelectric thin-film varactors as tuning elements at the resonator ends. The implemented prototype filter can be tuned continuously in the frequency region from 1.8 GHz to 2.1 GHz exhibiting a worst case insertion loss of less than 3 dB and passband return loss better than 20 dB at all operating bias states. Excellent agreement between simulation and measurement results is obtained for the proposed topology at all tuning states. An output referred 3 rd order intercept point of 36.5 dBm was measured by a two tone setup.
elib2cris::1512001600,lourandakis2009a
Keywords: Ferroelectric capacitors; bandpass filters; tunable filters

A Fifth-Order Low-Pass Continous Time Delta-Sigma with Four Pairs of Conjugate Complex NTF Zeros - Zeller, Christian; Muenker, Christian; Weigel, Robert (Workshop Analogschaltungen, 2011)
elib2cris::1512001600,zeller2011c

A Finite 3D Field Simulation Method for Permittivity Gradient Implementation of a Novel Porosification Process in LTCC - Talai, Armin; Steinhäußer, Frank; Schmid, Ulrich; Weigel, Robert; Bittner, Achim; Kölpin, Alexander (IEEE MTT-S International Microwave Symposium, 2013)
High frequency substrates show a manifold variety of complex permittivities for different applications. Recent research results demonstrated the possibility of local decrease of the permittivity on LTCC by chemical etching processes, which enables the design of high quality antennas on LTCC. This paper shows a novel approach on the determination of the quantitative reduction of the effective permittivity by scanning electron microscope analyses in combination with finite 3D field simulations of the resulting inhomogeneous material. By the characterization of two different porosified LTCCs it could be shown that this process is suitable for direct antenna integration on glass-ceramic substrates with enhanced values of relative permittivities.
elib2cris::1512001600,talai2013a
Keywords: Field simulation; LTCC; local reduction of permittivity; porosification; wet chemical etching; inhomogeneous substrate; permittivity gradient

A fith-order low-pass continuous time delta-sigma ADC with four paris of conjugate complex NTF zeros - Zeller, Sebastian; Münker, Christian; Weigel, Robert (Kleinheubacher Tagung, 2010)
elib2cris::1512001600,zeller.2010

A flexible mixed-signal image processing pipeline using 3D chip stacks - Shi, Lan; Söll, Christopher; Pfundt, Benjamin; Bänisch, Andreas; Reichenbach, Marc; Seiler, Jürgen; Ussmueller, Thomas; Weigel, Robert (Journal of Real-Time Image Processing, 2016)
This work presents a highly flexible mixed-signal CMOS image sensor suitable for smart camera applications. These systems need to fit different constraints regarding power consumption, speed and quality, and the optimal compromise may differ depending on the application. Moreover, the best implementation of a desired image processing task may be in the analog or the digital domain, or even a combined computation. Different aspects starting from the image sensor and signal acquisition up to the pre-processing in analog and digital domain are investigated in this paper to optimize not just one part of the system, but the whole system altogether. Moreover, it is shown that analog processing algorithms can improve signal quality, processing speed and latency while being able to save power, which is important for real-time systems. In order to be able to carry out spatial operations, the state-of-the-art sensor is modified to be able to read out multiple pixels at the same time. This allows analog spatial filter operations which consume significantly less power. As an example, an averaging filter is described which needs less than 5.3 % of the power–time product of a digital implementation for one computation. To enhance data throughput and flexibility, 3D chip stacking is proposed to partition the sensor in smaller units and enable massively parallel processin
Keywords: 3D chip stacking; Analog pre-processing; Application optimized image pipeline; Partitioning; Smart camera

A Flexible Multiband Frontend for Software Radios using High IF and Active Interference Cancellation - Schacherbauer, Werner; Springer, Andreas; Ostertag, Thomas; Ruppel, Clemens; Weigel, Robert (IEEE International Microwave Symposium, 2001)
A flexible analog frontend for multiband mobile communications equipment is presented. The circumvention of tight RF band filtering as applied in current single-band designs is fundamental to attain this goal. A successful application of wideband RF filtering, covering all frequency bands of interest, combined with a high intermediate frequency stage and active interferer cancellation is demonstrated. The high intermediate frequency following the RF stage allows for respectively image and sideband rejection. Direct feedthrough of the TX signal into the RX path is suppressed by active cancellation. A demonstrator capable of operating within an RF range from 800 to 2200 MHz with variable channel bandwidths up to 5 MHz has been realized and measurement results are presented and discussed.
elib2cris::1512001600,schacherbauer2001
Keywords: multiband frontend; software radios; active interference cancellation

A Flexible Multistandard Software Radio Frontend Concept - Schacherbauer, Werner; Springer, Andreas; Ruppel, Clemens; Weigel, Robert (4th European Conference on Wireless Technology, 2001)
elib2cris::1512001600,schacherbauer2001a
Keywords: Software Radio Frontend; Multistandard

A Frequency-Agile Terminal Receiver for Wireless Multi-Standard Applications - Maurer, Linus; Hueber, Gernot; Dellsperger, Thomas; Burger, Thomas; Huemer, Mario; Weigel, Robert (Proceedings of the IEEE Radio and Wireless Symposium, 2006)
elib2cris::1512001600,maurer2006

A Full D-Band Low Noise Amplifier in 130 nm SiGe BiCMOS using Zero-Ohm Transmission Lines - Maiwald, Tim; Potschka, Julian; Kolb, Katharina; Dietz, Marco; Aufinger, Klaus; Visweswaran, Akshay; Weigel, Robert (15th European Microwave Integrated Circuits Conference (EuMIC), 2021)

A Full D-band Multi-Gbit RF-DAC in 90 nm SiGe BiCMOS based on Passive Vector Aggregation - Maiwald, Tim; Visweswaran, Akshay; Aufinger, Klaus; Weigel, Robert (ESSCIRC 2022 - IEEE 48th European Solid State Circuits Conference, Proceedings, 2022)
This paper presents the first fully integrated RF-DAC for realizing and passively scaling QPSK-signals for generating higher-order modulations over the entire D-band (110-170 GHz). Vector-symbol generation in the RF-DAC is accomplished via compact distributed passives on chip. In this modulator architecture, a sinusoidal local-oscillator (LO) signal is split and weighted by a backward-wave directional coupler to meet length requirements for a complex-valued RF-signal scaling vector. QPSK vector-modulation is then accomplished with a Lange Coupler, two Marchand baluns and a switch octet operating on four LO phases (0°, 90°, 180° and 270°), which is driven directly with the data streams. Higher-order modulation schemes are subsequently created by summing RF outputs of individual QPSK unit cells. A 16-QAM modulator, based on two-way summing, prototyped in Infineon's advanced 90 nm SiGe BiCMOS technology demonstrating a datarate of 6.4 Gbps with a measured EVM of <8% over the entire D-band. Simulations show a maximum datarate of 60 Gbps, however, the measured datarate is currently limited by the test setup comprising an in-house low-cost FPGA clocked at 1.6 GHz. The chip consumes 120 mW from a 2.1 V supply and occupies 0.36 mm2 of core area.
CRIS-Team Scopus Importer:2022-11-25
Keywords: 5G; 6G; D-band; direct modulation; QAM; RF-DAC

A fully differential 77-GHz active IQ modulator in a silicon-germanium technology - Wagner, Christoph; Hartmann, Marcus; Stelzer, Andreas; Jäger, Herbert (IEEE Microwave and Wireless Components Letters, 2008)
elib2cris::1512001600,wagner2008

A Fully Differential Low-Power High-Linearity 77-GHz SiGe Receiver Frontend for Automotive Radar Systems - Kissinger, Dietmar; Weigel, Robert (Wireless and Microwave Technology Conference, 2009)
elib2cris::1512001600,kissinger2009

A fully-differential Operational Amplifier using a new Chopping Technique and Low-Voltage Input Devices - Mai, Timo; Schmid, Konstantin; Hagelauer, Amelie Marietta; Weigel, Robert; Röber, Jürgen (24th IEEE International Conference on Electronics, Circuits and Systems, 2017)
A fully differential CMOS operational amplifier is presented. It uses a new chopping technique that works without the use of switching transistors in the high gain path, resulting in high noise performance and low offset. It is designed in a low-cost 180 nm process with a 5V supply voltage. In critical places, such as the differential pair, 1.8V-devices are used, as they provide much better matching and noise performance, and at the same time have lower parasitics. They are protected from breakdown conditions by several circuit techniques. Some of them are described below. The operational amplifier is used in a differential programmable gain amplifier for processing signals of up to 50 kHz bandwith with a SINAD > 100 dB, making it suitable as a preamplifier for 18-Bit ADCs.
Keywords: chopping; operational amplifier; gain boosting; 1/f-noise; offset; programmable gain amplifier

A Fully Digital Method for the Generation of Sinusoidal Waveform for the Built-In Self-Test (BIST) of the Audio chip. - Li, Hongzhi; Eckmüller, Josef; Sattler, Sebastian; Eichfeld, Herbert; Weigel, Robert (2nd VDE World Microtechnologies Congress, 2003)
elib2cris::1512001600,li2003d
Keywords: Digital; sinusoidal; waveform generation; BIST; Built-In-Self-Test; audio chip

A fully integrated 120-GHz six-port receiver front-end in a 130-nm SiGe BiCMOS technology - Lämmle, Benjamin; Schmalz, Klaus; Borngraeber, J.; Scheytt, Christoph; Weigel, Robert; Kölpin, Alexander; Kissinger, Dietmar (2013 IEEE 13th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, 2013)
A fully integrated six-port receiver front-end at 120 GHz center frequency including a low-noise-amplifier, a passive six-port network, a VCO, and four direct converters is presented in this publication. The overall architecture of the designed six-port receiver is analyzed and fundamental theory of the receiver given. The design of the six-port building blocks is described and measurement results are presented. All circuits have been fabricated in a 0.13μm 300-GHz fT SiGe BiCMOS technology. The fully integrated receiver consumes 85.9 rnA from a 3.3-V supply and occupies an area of 1.03mm2. The receiver includes a VCO with a center frequency of 117.15 GHz, a tuning range of 2.7 GHz, and a phase noise of -86 dBc/Hz at 1 MHz offset. The LNA shows a gain of 12 dB, a 3-dB bandwidth of 30 GHz at a power consumption of 9.2 rnA. The six-port core has a conversion gain of 3.6 dB, a P1dB of -12 dBm, and a power consumption of 28 rnA. The overall receiver shows a conversion gain of 2.4 dB at 120 GHz and P1dB of -17 dBm.
elib2cris::1512001600,laemmle2013

A Fully Integrated Analog Baseband IC for an UMTS Zero-IF Receiver - Weigel, Robert; Pretl, Harald; Maurer, Linus; Schelmbauer, Werner; Fenk, Josef; Adler, Bernd (Proceedings Austrochip, 2000)
UnivIS-Import:2015-04-16:Pub.2001.tech.IE.LETE.afully

A Fully-Integrated BiCMOS IF Transceiver for W-CDMA Mobile Applications. - Thomann, Wolfgang; Eschlböck, Gernot; Fuchs, Hans-Peter; Habring, G.; Haider, Günter; Heigelmayr, Bernhard; Minichshofer, Jürgen; Novak, Dieter; Pankratz, Thomas; Pimingsdorfer, Dieter; Scheiber, Andreas; Stephelbauer, Carl; et al. (6th European Conference on Wireless Technology, 2003)
A fully-integrated, single-chip, intermediate frequency (IF) transceiver (TRX) with on-chip synthesizer, a novel vector-modulator/divider structure for receiver local oscillator (LO) generation from transmitter LO, and analog continuoustime baseband filters with automatic filter calibration is presented. The transceiver is intended for third-generation (3G) Wide-Band Code Division Multiple Access (W-CDMA) mobiles and has been implemented in a standard, high frequency, Si-BiCMOS process with a bipolar of 25 GHz and a gate length of 0.5 um. The transceiver complies with Association of Radio Industries and Businesses (ARIB) W-CDMA and UMTS standards.
elib2cris::1512001600,thomann2003b
Keywords: Fully Integrated; BiCMOS; IF; Transceiver; W-CDMA; mobile

A fully integrated bulk-CMOS switch based tunable transformer for RF and antenna matching - Bakalski, Winfried; Thomas, Anthony; Weigel, Robert (IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications (PAWR), 2013)
A fully integrated tunable RF impedance matching network based on a transformer topology and on-chip RF switches is presented. Using the Infineon 130 nm Bulk-CMOS RF switch process with 2.4 μm alumina top metal, the chip integrates a 4-bit digitally tunable capacitor, a planar transformer with 4 independent windings and 12 taps, an on-chip charge pump and RF switches to control the operating mode of capacitor and the transformer. The circuit offers the possibility to cover the Smith Chart at either low and high impedance up to a VSWR of 10 on the GSM band 790-960 MHz. In by-pass mode the insertion loss is 0.8 dB at 850 MHz and features a harmonic generation of - 85 dBc (H2) and -75 dBc (H3) without the need of any external devices or extra controller. The current consumption at 1.5 V is 120 μA.
elib2cris::1512001600,bakalski2013
Keywords: CMOS integrated circuits; UHF antennas; UHF integrated circuits; impedance matching; microwave switches; transformer windings; GSM band; Infineon bulk-CMOS RF switch process

A Fully Integrated Continuous-Time Channel Selection Filter for a UMTS Zero-IF Receiver - Schelmbauer, Werner; Maurer, Linus; Pretl, Harald; Adler, Bernd; Weigel, Robert (ITG-Workshop Mikroelektronik für die Informationstechnik, 2000)
elib2cris::1512001600,schelmbauer2000a
Keywords: UMTS; Filter

A Fully Integrated VCO at 2GHz - Zannoth, Markus; Kolb, Bernd; Fenk, Josef; Weigel, Robert (IEEE International Solid-State Circuits Conference, 1998)
An integrated voltage-controlled oscillator (VCO) at a frequency of 2 GHz is implemented in a f/sub T/= 25 GHz standard bipolar process. The phase noise of the VCO is -136 dBc/Hz at 4.7 MHz frequency offset. The LC-resonator uses vertically coupled on-chip inductors and integrated tuning diodes. Due to the poor performance of integrated resonators on silicon ICs, oscillators with phase noise meeting requirements of wireless applications are difficult to integrate. With fully integrated designs only the standards for cordless phones, for instance DECT, can be achieved. The critical point in the DECT-specification is the emission of the transmitter due to intermodulation in the third adjacent channel, that must be <-47 dBm. This value is measured with an integration bandwidth of 1 MHz centered at the nominal center frequency. With a channel-spacing of 1.728 MHz the third adjacent channel is located 5.184 MHz from the actual transmit channel frequency. The beginning of the integration bandwidth is at an offset frequency of 4.684 MHz related to the nominal frequency of the transmit channel. This is the offset frequency, at which the specification must be met. The resulting noise requirement is -132 dBc/Hz at a offset frequency of 4.684 MHz, when the integration bandwidth and the transmit output power of 25 dBm are taken into account.
elib2cris::1512001600,zannoth1998a

A fully integrated VCO at 2 GHz - Zannoth, Markus; Kolb, Bernd; Fenk, Josef; Weigel, Robert (IEEE Journal of Solid-State Circuits, 1998)
A fully integrated voltage-controlled oscillator at a frequency of 2 GHz with low phase noise has been implemented in a standard bipolar process with a f/sub t/ of 25 GHz. The design is based on an LC-resonator with vertical-coupled inductors. Only two metal layers have been used. The supply voltage of the oscillator is 2.7 V. The phase noise is only -136 dB/Hz at 4.7 MHz frequency offset. A tuning range of 150 MHz is achieved with integrated tuning diodes.
elib2cris::1512001600,zannoth1998b

A fundamental-frequency 122 GHz radar transceiver with 5.3 dBm single-ended output power in a 130 nm SiGe Technology - Aguilar, Erick; Issakov, Vadim; Weigel, Robert (IEEE MTT-S International Microwave Symposium Digest, 2020)
A fundamental-frequency D-Band transceiver (TRX) module in a 130 nm SiGe HBT technology for radar applications is presented. The module achieves in measurements a phase noise of -89 dBcI/Hz at an offset frequency of 1 MHz with an output frequency of fTX=122 GHz and operates in the frequency range of 110 - 125 GHz. A measured maximum conversion gain (CG) of 8.5 dB at fIF = 1 GHz is observed. Due to limitations of available measurement equipment, the output power had to be measured in a single-ended manner. Under this consideration, an output power of 5.3 dBm is measured, which to the best of the author's knowledge, corresponds to the highest output power reported so far for a fully-integrated fundamental-frequency-based TRX module including on-chip LO generation in the 120 GHz frequency range. By employing a differential antenna at the output, the TRX can potentially generate an effective output power of about 8 dBm.
CRIS-Team Scopus Importer:2020-11-06
Keywords: D-Band; Fundamental-frequency; High-power; Highly-integrated; SiGe; Transceiver; TRX

A Grounded Coplanar Waveguide Resonator Based In-Line Material Characterization Sensor - Talai, Armin; Mann, Sebastian; Weigel, Robert; Kölpin, Alexander (German Microwave Conference (GeMIC), 2016)
Microwave Materials such as Rogers RO3003 are subject to process-related fluctuations in terms of the relative permittivity. The behavior of high frequency circuits like patchantenna arrays and their distribution networks is dependent on the effective wavelength. Therefore, fluctuations of the relative permittivity will influence the resonance frequency and antenna beam direction. This paper presents a grounded coplanar waveguide based sensor, which can measure the relative permittivity at 77GHz, as well as at other resonance frequencies, by applying it on top of the manufactured depaneling. In addition, the sensor is robust against floating ground metallizations on inner printed circuit board layers, which are typically distributed over the entire surface below antennas.
elib2cris::1512001600,talai2016
Keywords: Antenna Array; Grounded CoplanarWaveguide; Differential Frequency; Electromagnetic Simulation; Floating Ground; Material Characterization; Relative Permittivity

A GSM-Network for Mobile Phone Localization in Disaster Scenarios - Rose, Richard; Meier, Christian; Zorn, Stefan; Götz, Alexander; Weigel, Robert (German Microwave Conference, 2011)
This paper deals with an adjustment and an implementation of a modified GSM-network. This network is necessary to enable the localization of mobile phones, primarily in disaster scenarios. In order to localize a mobile phone it is mandatory, that the phone transmits a signal. As a mobile phone transmits only sporadically without request, it has to be enforced to send a signal to be localized. The enforcing of a transmission is done by means of bringing up an auxiliary GSM-network. The configuration of the GSM-network allows the usage of a special handover procedure with frequency hopping. The implementation of frequency hopping considerably increases the accuracy of applied localization techniques.
elib2cris::1512001600,rose2011

A high accuracy Direction-Of-Arrival and Misalignment Angle Detector - Vinci, Gabor; Barbon, Francesco; Weigel, Robert; Kölpin, Alexander (German Microwave Conference, 2011)
High-precision Direction-Of-Arrival measurements are often a challenge. The need to accurately detect the angle of incidence of an incoming electromagnetic wave with respect to a reference geometrical axis is very important for automotive and security applications. Furthermore, the ability to measure a misalignment angle of a transmitting antenna in respect to a reference is a task required by countless industrial applications. A high accuracy angle-detection system is hereby presented and measurement results from a prototype detecting a 24 GHz source are shown.
elib2cris::1512001600,vinci2011

A High Accurarcy Post-Synchronization Method for Secondary Radar Systems - Kaiser, Markus; Hüttner, Jörg; Ziroff, Andreas; Weigel, Robert (9th European Radar Conference (EuRAD), 2012)
A post-synchronization method for a localization system is presented here. The synchronization of independent secondary radar units of an active localization system is essential. There are different synchronization techniques. One of these is FSK-pre-synchronization, which is analysed in this paper. The precision of the pre-synchronization is not accurate enough for round trip phase measurement. The undesirable side-effects which distort the synchronization between the active radar units have been analysed and a compensation method developed. The radar units operate in the 5.8 GHz ISM band. To verify how accurately the novel post-synchronization method works a round trip phase measurement has been implemented. With the novel post-synchronization a ranging accuracy of 0.1824 cm is possible.
elib2cris::1512001600,kaiser2012
Keywords: compensation; frequency shift keying; millimetre wave radar; phase measurement; synchronisation; FSK-presynchronization; ISM band; compensation method; frequency 5.8 GHz; high accuracy post-synchronization method; localization system; round trip phase measurement; secondary radar system; Accuracy; Delay; Distance measurement; Frequency shift keying; Phase measurement; Radar; Synchronization

A High Frequency Low Noise Acoustic STW VCO - Fleischmann, Bernd; Russer, Peter; Schaller, A.; Weigel, Robert (19th European Microwave Conference, 1989, 1989)
A voltage controlled oscillator (VCO) at 2.65 GHz has been developed using acoustic surface transverse wave (STW) delay lines operating at the fifth harmonic as the frequency controlling element. A filter with three transducers has been designed. The STW filter also serves as the oscillator output coupler. Compared to a microstrip coupler, the spectral characteristic of the oscillator is strongly improved due to the high selectivity of the transducer type coupler. The Q value and the untuned insertion loss of the filter were 3600 and 30 dB, respectively. A very thin metallization of only 25 nm aluminum was used for the STW filter. Excellent phase noise data have been measured. A single-sideband phase noise to carrier ratio of ¿93 dBc/Hz at 1 kHz and ¿63 dBc/Hz at 100 Hz was attained. As a phase shifter, a GaAs varactor diode circuit is used. Tuning range and output power of the oscillator were ± 375 kHz and 3 dBm, respectively. The load pulling (frequency stability) is ± 3.5 kHz at 12 dB return loss. Attenuation of harmonics is higher than 44 dB referred to the carrier.
–empty–::1512001600,fleischmann1989
Keywords: Acoustic noise; Acoustic transducers; Delay lines; Frequency; Microstrip; Phase noise; Power harmonic filters; Surface acoustic waves; Voltage control; Voltage-controlled oscillators

A High-Gain High-Linearity Tapered Distributed Amplifier for Ultra-Wideband-Applications Using a Low Cost SiGe BiCMOS Technology - Sewiolo, Benjamin; Kissinger, Dietmar; Fischer, Georg; Weigel, Robert (IEEE Wireless and Microwave Technology Conference, 2009)
elib2cris::1512001600,sewiolo2009c

A High-Linearity Broadband 55-77 GHz Differential Low-Noise Amplifier with 20 dB Gain in SiGe Technology - Kissinger, Dietmar; Aufinger, Klaus; Meister, Thomas; Maurer, Linus; Weigel, Robert (Asia-Pacific Microwave Conference (APMC 2010), 2010)
This paper presents a broadband differential current re-use low-noise amplifier with 30% fractional bandwidth at a center frequency of 66 GHz. The circuit has been manufactured in an advanced SiGe:C HBT technology with ft/fmax = 220/285 GHz. The amplifier is unconditionally stable and achieves a maximum differential gain of 19.7 dB while operating over a 3-dB bandwidth of 22 GHz. At the upper corner frequency of 77 GHz the amplifier exhibits a noise figure of 5.8 dB and linearity measurements show a 1-dB output referred compression point above +3 dBm. The circuit consumes 40 mW from a 3.3 V supply and occupies a chip area of 728 × 728 μm2 including bond pads.
elib2cris::1512001600,kissinger2010e
Keywords: Broadband communication; CMOS integrated circuits; Frequency measurement; Gain; Noise; Silicon; Silicon germanium

A High-Linearity Tapered Distributed Amplifier for Ultra-Wideband-Applications - Sewiolo, Benjamin; Fischer, Georg; Weigel, Robert (German Microwave Conference, 2009)
elib2cris::1512001600,sewiolo2009a

A highly adaptable ultra-low weight wireless sensor network for tracking and monitoring of airborne vertebrates - Duda, Niklas; Weigel, Robert; Koelpin, Alexander (2020 23rd International Microwave and Radar Conference, MIKON 2020, 2020)
This paper gives an overview of the BATS project, which aims to track the behavior of bats by developing an ultra-low power wireless sensor network. It is composed of an ultra-low weight sensor node that is attached to the animal and extensive ground infrastructure for tracking the animals as well as remote data download of locally stored sensor data from the tags. The system achieves its low power consumption by adaptively enabling certain functions based on the current situation. The mobile node, as a key component of the system, contains a variety of sensors, including an electrocardiogram (ECG) to allow precise insights in the animals' behavior while maintaining a low weight of around 1 g depending on the hardware configuration.
CRIS-Team Scopus Importer:2020-12-25
Keywords: Low power; Sensors; Wireless sensor network

A Highly Efficient UHF RFID Frontend Approach - Essel, Jochen; Brenk, Daniel; Heidrich, Jürgen; Weigel, Robert (Internationla Microwave Workshop on Wireless Sensing, Local Positioning and RFID, 2009)
elib2cris::1512001600,essel2009

A Highly-Integrated 60 GHz Receiver for Radar Applications in 28 nm Bulk CMOS - Ciocoveanu, Radu; Weigel, Robert; Issakov, Vadim (2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2020)
This paper presents a low-power highly-integrated 57-64 GHz receiver for short-range frequency-modulated continuous-wave (FMCW) radar applications and fabricated in a 28 nm CMOS technology. Measurement results show that the receiver (Rx) achieves a 18.9 dB conversion gain (CG) with a -12 dBm input referred 1-dB compression point (IP1dB) at 60 GHz. A 7.6 dB double sideband noise figure (NF dsb ) is achieved at 10 MHz offset. Furthermore, the circuit draws 44 mA from a single 0.9 V supply and the chip core size is 0.58 mm × 0.33 mm.<br

A Highly Integrated Dual-channel Configurable GNSS Receiver Front-end for Wideband Reception - Urquijo, Santiago; Rügamer, Alexander; Milosiu, Heinrich; Felber, Wolfgang (PROCEEDINGS OF THE 32ND INTERNATIONAL TECHNICAL MEETING OF THE SATELLITE DIVISION OF THE INSTITUTE OF NAVIGATION (ION GNSS+ 2019), 2019)
CRIS-Team WoS Importer:2021-10-18

A highly-integrated fractional-N synthesizer for FMCW radar - Eickhoff, Ralf; Ellinger, Frank; Ußmüller, Thomas; Spiegel, Solon (IEEE International Conference on Microwaves, Communications, Antennas and Electronic Systems, 2008, 2008)
This paper presents an integrated synthesizer for frequency ramp generation in local positioning systems using frequency modulated continuous wave (FMCW) radar in the ISM band at 5.8 GHz. The synthesizer is designed and implemented as a fractional-N phase locked loop (PLL) in a 0.18 mum SiGe-BiCMOS technology controlled by a MASH 1-1-1 SigmaDelta-modulator, which is integrated on an FPGA. Besides preventing spurs in the output spectrum, this digital control allows a flexible programming of the synthesizer with respect to its frequency ramp generation and output spectrum respectively. The complete fractional-N synthesizer was integrated into a single system PCB and measurements regarding phase noise and tuning range were performed. Moreover, an FMCW radar system using this synthesizer achieved an accuracies of 13 cm in indoor environments.
elib2cris::1512001600,eickhoff2008b

A Highly Integrated Single-Chip Baseband IC for 2.5th Generation Multimedia Oriented Mobile Phones - Huemer, Mario; Lüftner, Thomas; Weigel, Robert; Hagelauer, Richard; Hausner, Josef (Elektrotechnik und Informationstechnik, 2002)
In this paper we report on the design and architecture of a single chip baseband processor IC for GSM/GPRS/EDGE cellular phone applications. S-GOLD is a mixed signal IC containing all analog and digital baseband functionality of a cellular radio. It is designed as a single chip solution, integrating the digital and mixed signal portions of the baseband in a leading edge 0.13 µm 1.5 V CMOS technology to meet the ever increasing demands of the GSM cellular subscriber market for feature rich and high performance terminals at low costs.
elib2cris::1512001600,huemer2002a
Keywords: mobile; Chip

A Highly Linear and Efficient 28 GHz Stacked Power Amplifier for 5G using Analog Predistortion in a 130nm BiCMOS Process - Potschka, Julian; Dietz, Marco; Kolb, Katharina; Maiwald, Tim; Breun, Sascha; Ackermann, Thomas; Ferling, Dieter; Hagelauer, Amelie Marietta; Weigel, Robert (PROCEEDINGS OF THE 2019 IEEE ASIA-PACIFIC MICROWAVE CONFERENCE (APMC), 2019)
CRIS-Team WoS Importer:2020-09-25

A Highly Linear Low-Power 28 GHz LNA in 45nm SOI-CMOS using the Modified Derivative Superposition Method for IM3-Cancellation - Lammert, Vincent; Weigel, Robert; Issakov, Vadim (PROCEEDINGS OF THE 2020 IEEE TEXAS SYMPOSIUM ON WIRELESS AND MICROWAVE CIRCUITS AND SYSTEMS (WMCS), 2020)
CRIS-Team WoS Importer:2021-03-12

A highly modular 77 GHz multi-tone FMCW SiGe radar concept for industrial measurements - Erhart, Christian; Lutz, Steffen; Mantz, Hubert; Walter, Thomas; Weigel, Robert (German Microwave Conference (GeMiC), 2015)
In this paper, a modular system for 77 GHz applications and a novel approach to increase the accuracy of distance measurements using angular phase shifts is presented. The sensor itself consists of state of the art MMICs and provides the opportunity to exchange the beam forming component easily. The radiation characteristics of the so far developed beam formers are illustrated and some exemplary distance measurements will be shown. The sensor prototype is integrated in a robust metal case, which is usable for measurements in harsh environments. Applications for the sensor include distance, velocity as well as surface and vibration analysis. The introduced distance measuring approach is based on FMCW multi tone modulation in combination with an innovative correlation evaluation.
elib2cris::1512001600,erhart2015

A Highly Reconfigurable RF-DPLL Phase Modulator for Polar Transmitters in Cellular RFICs - Buckel, Tobias; Tertinek, Stefan; Mayer, Thomas; Bauernfeind, Thomas; Wicpalek, Christian; Springer, Andreas; Weigel, Robert; Ussmueller, Thomas (IEEE Transactions on Microwave Theory and Techniques, 2018)

A Highly Sensitive Glucose Biosensor Based on a Microstrip Ring Resonator - Schwerthöffer, Udo; Weigel, Robert; Kissinger, Dietmar (2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications, 2013)
elib2cris::1512001600,schwerthoeffer2013a

A High Performance Line Filter for Narrowband Power Line Communication Testbed Applications - Müller, Steffen; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (IEEE International Conference on Smart Grid Communications (SmartGridComm), 2013)
This paper is presenting a two-stage line filter design, optimized for power line communication (PLC) testbed applications in the frequency range from 9 kHz to 500 kHz. The filter shows a very high differential mode attenuation together with a high input impedance on load-side. It enables to cope with the harsh noise characteristics of the PLC channel, as well as varying line access impedances in order to build up testbeds without any additional equipment. After exploring the filter’s architecture, SPICE simulations and measurement results are carried out, while the latter are discussed with respect to two commercial off-the-shelf filters.
elib2cris::1512001600,mueller2013
Keywords: Power Line Communication; Smart Grid; Line Filter; Electromagnetic Interference; Testbed

A High Precision Reconfigureable Bistatic Interferometric Radar with Integrated Six-port Receiver at 60 GHz - Völkel, Matthias; Mann, Sebastian; Frank, Martin; Weigel, Robert; Hagelauer, Amelie Marietta (2019 12th German Microwave Conference (GeMiC), 2019)
In this paper a 60GHz bistatic reconﬁgureable sixport radar for high precision measuring is presented. The frontend is designed in a substrate-integrated waveguide technology including coupler, attenuator and transmission lines. The core of the front-end is a integrated six-port receiver MMIC including the passive six-port structure, a LNA and four detectors. It has been designed using a 0.13µm SiGe BiCMOS process. A BGT60, stabilized by a PLL-circuit, generates the transmit signal for vivaldi antennas. The system includes also a baseband circuit with adjustable differential ampliﬁer, 24bit@52kSa/s ADC converter for signal sampling and DAC converter for gain and attenuation tuning. Furthermore, the stacked system is directly connected to a FPGA board. A full NIOS2 system is set up to control the radar and send the collected data via ethernet to the PC. C++ software is written to conﬁgure the system in an easy comfortable way and to visualize the measured data. Measurements show, that the radar works in a range up to ﬁve meter. The maximum distance deviation at 1m is 30µm and the standard deviation is 12.6µm.<br
Keywords: bistatic; FPGA; integrated receiver; interferometry; millimeter wave circuits; radar systems; six-port; substrateintegrated waveguide (SIW)

A High-Sensitivity Radar System Featuring Low Weight and Power Consumption - Mann, Sebastian; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (IEEE Microwave Magazine, 2015)
In this article, a lightweight, low-power radar system for vibration monitoring has been presented. Based on a theoretical analysis of the competition scenario, an optimized system concept has been developed. The radar front end is able to sequentially evaluate the in-phase and quadrature component of the received signal with only a single hybrid coupler and power detector, reducing the overall weight to 5 g including the power-supply cable. A low duty cycle of 1% allowed the power to average 1.5 mW. As the minimum required sensitivity was limited to 0.5-mm oscillation amplitude, the most challenging parts in this student competition were, in our opinion, the tight power and weight optimizations. As the competition required only vibration detection butno ranging, a minimalistic system concept optimized for this application was proposed. The system features a free-running VCO sourced directly from the power supply without any further stabilization. For ranging applications, temperature changes as well as supply and tuning voltage variations at the VCO could have a severe impact on the system's accuracy. However, for pure vibration detection of a well-defined target, this is not a problem. Further improvements could be achieved when designing a customized 24-GHz oscillator, optimized for high efficiency [9] and fast turn-on time. In addition, the necessary number of measurements per second could be further investigated. Currently, with ten measurements per second, there is a convenient safety margin against false detections; however, fewer measurements would directly reduce the duty cycle and thus the average power consumption of the system.
elib2cris::1512001600,mann2015a
Keywords: Low Power; Radar

A Hybrid Acoustic-Wave Resonator and Lumped-Element Ladder Filter - Wagner, Michael; Gossmann, Timo; Tomasik, Jakob; Weigel, Robert; Hagelauer, Amelie Marietta; Leuschner, Stephan (IEEE International Ultrasonics Symposium, IUS, 2018)
RF frequency filters employing acoustic-wave resonators are used in common modern handsets for mobile communication. These resonators make use of the piezoelectric effect, i.e. their characteristics therefore strongly depend on employed materials and technology and comprise relatively fixed behavior. Classic filter design theory, however, is dealing with lumped reactive elements like inductors and capacitors for the realization of any-order filter designs instead. This theoretical treatment can lead to a multitude of realizable designs which makes it in fact very generous but also complex. Furthermore, theory is well-known and resulting structures are excessively explored in practice. In this paper, a new practical approach for the combination of these two filter types, preserving their respective benefits, is presented.
Created from Fastlane, Scopus look-up

A Hybrid Method for Determining the Coupling Coefficient of Near Field Identification Systems - Iliev, Stoyan; Abou-Chahine, Zeid; Luy, Johann-Friedrich; Weigel, Robert (38th European Microwave Conference, 2008, 2008)
In this paper a hybrid method for determining the coupling coefficient of the near field identification systems is suggested. The method is called hybrid, because it processes the simulation data from full wave field simulator in the PSpice environment. By combination of the S parameter simulation, which describes the spacial interaction between the two coils of the near field identification system at the resonant frequency and PSpice simulation, where the exact currents in the coils can be obtained, it is possible to determine the coupling factor between the coils fast and with high accuracy, without the necessity of building a sophisticated measurement setup. Additionally the performance of the system could be evaluated under different surrounding conditions, since metallic walls and dielectric structures could be easily implemented into the full wave field simulator environment.
elib2cris::1512001600,iliev2008

Air-to-ground channel characterization for OFDM communication in C-Band - Blümm, Christian; Heller, Christoph; Fourestie, B.; Weigel, Robert (7th International Conference on Signal Processing and Communication Systems (ICSPCS), 2013)
Knowledge of the propagation channel is essential for the design and optimization of wireless communication systems. This paper presents the case study of an ongoing data link development for air-to-ground telemetry in C-band, based on Orthogonal Frequency Division Multiplexing (OFDM). A novel easy-to-use channel sounding technique is applied to identify specific small-scale channel fading effects. With the obtained information, the OFDM system can be parameterized in terms of subcarrier spacing and cyclic prefix. This helps to maximize data throughput and robustness even for worst-case aircraft positions and maneuvers.
elib2cris::1512001600,bluemm2013b
Keywords: OFDM modulation; optimisation; radio networks; space telemetry; wireless channels; C-Band; OFDM communication; air-to-ground channel characterization; air-to-ground telemetry; channel sounding technique

Aktive phasengesteuerte Planarantenne mit Adaption von Richtcharakteristik und Polarisation für den TVSatellitenempfang - Fischer, Georg (ITG-Diskussionssitzung Antennen für Mobile Systeme, 1996)
Keywords: Adaptive Arrays; Broadcast

Aktivitäts- und Sturzdetektion von Personen am Handgelenk - Zimmermann, Lars (RADCOM, 2013)
elib2cris::1512001600,zimmermann2013

Aktuelle Ansaetze im Bereich der linearen HF Leisungsverstaerker - Musolff, Christian (Electrical and Electronic Engineering for Communication Workshop - Entwicklerforum - Fachmesse, 2012)
elib2cris::1512001600,musolff2012

Aktuelle Forschungsprojekte im Bereich LED-Technologie an der Fachhochschule Bielefeld - Werner, Daniel; Schwenzfeier-Hellkamp, Eva (2. Symposium Intelligente Gebäudetechnologien, 2012)

Akustik im Bereich Mechatronik der Universität Linz - Lerch, Reinhard; Weigel, Robert (48. Jahrestagung der Österreichischen Physikalischen Gesellschaft (ÖPG) - Fachtagung Akustik, 1998)
elib2cris::1512001600,lerch1998

Akustische Oberflaechenbauelemente im UHF-Bereich - Weigel, Robert (VDI-Verlag, 1993)
elib2cris::1512001600,weigel1993a

Akustische Oberflaechenwellentechnik - Weigel, Robert (TUM-Mitteilungen, 1994)
elib2cris::1512001600,weigel1994

Al1-xScxN-based BAW filters for mobile communications - Hagelauer, Amelie Marietta; Bogner, Andreas (Virtual Electronic Materials and Applications 2021, 2021)

A Large Deflection Model of Silicon Membranes for Testing Intrinsic Stress of MEMS Microphones by Measuring Pull-In Voltage - Oesterle, Florian; Fink, Franz; Dehe, Alfons; Kuhn, Harald; Weigel, Robert; Kölpin, Alexander (SPIE Microtechnologies, Smart Sensors, Actuators, and MEMS VI, Conference 8763, 2013)
Mechanical parameters, especially mechanical stress of membranes used in silicon microphones strongly depend on the manufacturing process. As a result, deviations during this process can result in sensitivity variations of the microphone. Therefore, the stress should be well controlled within a certain tensile level. This paper describes a method to test devices electrically using the MEMS related pull-in phenomenon with respect to the mechanical compliance of microphone membranes. Using this method, out of specification chips can be detected at an early stage within the manufacturing process instead of determination at a system functionality test after packaging. Therefore, the adequacy for the intended use of the pull-in voltage and its dependency on varying tensile stress due to manufacturing tolerance is evaluated.
elib2cris::1512001600,oesterle2013c
Keywords: Inspection equipment; Manufacturing; Microelectromechanical systems; Silicon

A laser probing system for characterization of SAW propagation on LiNbO/sub 3/, LiTaO/sub 3/, and quartz - Holm, Andreas; Weigel, Robert; Russer, Peter; Ruile, Werner (IEEE MTT-S Internation Microwave Symposium Digest, 1996, 1996)
A nondestructive high-resolution technique for the optical detection of the phase and amplitude of high-frequency surface acoustic wave (SAW) devices is presented. The setup incorporates a mode-locked ps-laser, harmonic mixing, and coherent detection. Dynamic range and minimum detectable surface displacement were 50 dB and 1 pm//spl radic/(Hz), respectively. The probing technique allows not only the measurement of the SAW field but also the precise direct determination of the phase velocity which is a fundamental design parameter in SAW technology. We present experimental results of the phase velocity of both SAW and Leaky SAW modes on quartz, LiNbO/sub 3/ and LiTaO/sub 3/ with an accuracy of up to 1.5.10/sup -5/. Our results agree very good with theory and other experiments.
elib2cris::1512001600,holm1996b
Keywords: acoustic materials; acoustic wave velocity measurement; acousto-optical effects; lithium compounds; Acoustic signal detection; harmonic mixing; optical detection; phase velocity

A leadless packaging concept for high frequency applications - Theuss, Horst; Dangelmaier, Jochen; Engl, Mario; Pressel, Klaus; Knapp, Herbert; Simbürger, Werner; Gnannt, K.; Eurskens, Wolfram; Hirtreiter, J.; Weigel, Robert (Electronic Components and Technology Conference, 2004)
We present a low cost leadless packaging concept for applications in the GHz region. This package concept has an ultra-miniaturized footprint, small dimensions of the contact pads, and a standard package height of 0.4 mm. Further reduction of the package height is possible. The semiconductor chip can be implemented in a wire bond or a flip chip version. We demonstrate the capability of this package concept by three different applications in the GHz region. First, we show the performance of a filter component, designed to suppress the 3rd harmonic in a GSM application. This example represents a wire bond version of the package concept. The other two demonstrators are high frequency bipolar transistors and frequency dividers working up to 30 GHz, respectively. They are based upon flip chip interconnects. The results show that the package concept using the flip chip version is not yet limited at frequencies of 30 GHz.
elib2cris::1512001600,theuss2004

A Lecture Course Series: From Concept Engineering to Implementation of Signal Processing Algorithms with FPGAs - Huemer, Mario; Lunglmayr, Michael; Pfaff, Markus (13th European Signal Processing Conference, 2005)
The design of complex modern embedded systems like wireless communication systems becomes increasingly inefficient. The methods used in the design process ranging from system concept design to hardware and/or software implementation are diverse, and typically managed by different teams with quite different expertise in a company. This naturally leads to communication problems between the teams. In this paper we highlight a new concept on hardware-oriented signal processing in education, where the same group of students passes through the whole design process. We describe a tripartite coordinated course series consisting of a lecture, a concept and simulation oriented exercise course using MATLAB and a practical course, where finally real hardware is developed using FPGAs (Field Programmable Gate Arrays).
elib2cris::1512001600,huemer2005
Keywords: Signal Processing; FPGA

A Light Weight 3x3 Switched Polarity URA Antenna and Receive System for Direction Finding - Depold, Andreas; Dorn, Christian; Erhardt, Stefan; Weigel, Robert; Lurz, Fabian (2022 IEEE Topical Conference on Wireless Sensors and Sensor Networks, WiSNeT 2022, 2022)
Minimizing the time it takes to locate and rescue victims from building collapses is critical for their survival chance. This scenario causes a challenging environment for radio frequency based localization. This paper introduces a direction finding system based on a 3x3 uniform rectangular array with integrated polarization switching for multipath mitigation intended for search and rescue applications. It is shown that utilizing two polarizations can be used to reduce or eliminate ambiguities caused by multipath propagation. Further approaches to optimize localization ability are discusse
CRIS-Team Scopus Importer:2022-04-15
Keywords: Antenna arrays; Direction-of-arrival estimation; phase detection; receivers

A linear and efficient Doherty PA at 3,5GHz - Musolff, Christian; Kamper, Michael; Abou-Chahine, Zeid; Fischer, Georg (IEEE Microwave Magazine, 2013)
elib2cris::1512001600,musolff2013
Keywords: power amplifier; Doherty; load modulation; linearity; IMD; cancellation; 3; 5GHz; efficiency; backoff; twotone; harmonic balance

A Linearized Calibration Technique Using Modulated Signals for Wideband Dual-Input Doherty Characterization - Illmer, Andreas; Deublein, Alexander; Weigel, Robert; Ackermann, Thomas (2024 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR), 2024)

A linear Watt-level power amplifier implemented in 28 nm standard CMOS technology - Oßmann, Patrick; Fuhrmann, Jörg; Dufrene, Krzysztof; Pretl, Harald; Springer, Andreas (Microwave Conference (APMC), 2014 Asia-Pacific, 2014)

A Link Quality Indicator for analog FM Transmission Systems - Brendel, Johannes; Schmidt, Axel; Fischer, Georg (IEEE Conference on Signal Processing and Communication Systems, 2013)
This work describes a method to determine the link quality of analog frequency modulated (FM) transmission systems (especially wireless microphones) with the help of digital signal processing. We exploit the amplitude variations of a disturbed FM transmission to estimate the signal to interference plus noise ratio (SINR) of the received signal. Furthermore, the statistical measure kurtosis is used to determine the type of interference. After the theoretic description and derivation of the algorithms, the approach is confirmed with simulations. Finally, measurements and results of a hardware implementation show the applicability of the presented link quality estimator for instance in cognitive wireless microphone systems.
elib2cris::1512001600,brendel2013b

All about Audio Data Reduction - Brandenburg, Karlheinz; Herre, Jürgen (117th AES Convention, 2004)
Eingeladene Konferenz-Workshop-Vorträge, Tutorials
Keywords: Tutorial Seminar

All-Pass Based Filter Design Using BAW Resonators - Bogner, Andreas; Bauder, Rudiger; Timme, Hans Jorg; Reccius, Christian; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE International Ultrasonics Symposium, IUS, 2019)
The integration of multiple bands and higher power standards lead to enhanced interference problems and make higher attenuation levels in next-gen RF-Front-Ends necessary. This paper introduces an all-pass based BAW filter design concept for notch, band-stop and band-pass filter topologies to indicate the possibilities and the impact of key parameters like material electromechanical coupling factor k-eff^2, piezoelectric material quality factor Qm and inductor losses QL. This work outlines the concept and design aspects. Also various examples will be proposed to show the main benefits of this approach.
CRIS-Team Scopus Importer:2020-02-21
Keywords: acoustic wave filter; all-pass network; BAW filter; BAW resonator

A low-complexity LMMSE equalizer for W-CDMA downlink receivers in large delay spread channels - Buchacher, C.; Zimmermann, Markus; Paul, Stefan; Huemer, Mario (Informationstagung Mikroelektronik ME 2008, 2008)
elib2cris::1512001600,buchacher2008

A Low-Cost 2.4 GHz Frequency Measurement System for Microsecond Time Domain Pulses Based on Six-Port Technology - Lurz, Fabian; Lindner, Stefan; Mann, Sebastian; Linz, Sarah; Barbon, Francesco; Weigel, Robert; Kölpin, Alexander (European Microwave Conference, 2014)
This paper presents a fast responding frequency measurement system based on Six-Port technology being able to determine precisely the frequency of very short time domain pulses of 1 μs and even less in the 2.4 GHz ISM band. By using a delay line the frequency measurement can be reduced to a phase measurement that can be quickly evaluated by the Six-Port network implemented with lumped components. Measurements show that the delay line, currently realized by a SMA cable, is extremely sensitive to temperature variations even in the range of 0.1 K. Thus, a temperature compensation method based on reference measurements is proposed and final measurements show that the system can reach a calibrated and temperature compensated error of only a few parts per million (ppm).
elib2cris::1512001600,lurz2014
Keywords: Frequency measurement; Delay line; Six-Port

A Low-Cost Laser Barrier Based Vectorial Velocity Measurement System - Lindner, Stefan; Weigel, Robert; Kölpin, Alexander (IEEE Sensors, 2016)
This paper describes a low-cost measurement system based on two crossed laser barriers to measure the angle, the position as well as the velocity of an object with known shape, which is passing the measurement system. Due to the simple system setup this leads to a low-cost vectorial speed measurement system, which is capable of high speed measurements. Furthermore, as a demonstrator, a table soccer ball speed measurement system will be presented, which shows the feasibility of the proposed system.
elib2cris::1512001600,lindner2016
Keywords: angle of arrival; velocity measurement; laser barrier; crossed laser; table soccer

A Low-Cost SAW-Resonator Transmitter for Radio Control Applications in the 70 cm-Band - Schirdewahn, Bernd; Ostertag, Thomas; Weigel, Robert; Riha, Gerd; Russer, Peter (Asia-Pacific Microwave Conference (APMC), 1992, 1992)
elib2cris::1512001600,schirdewahn1992
Keywords: Capacitance; Frequency; Optical resonators; Optical transmitters; Oscillators; RLC circuits; Radio control; Radio transmitters; Resonance; Surface acoustic waves

A low cost ultra-wide-band inverted F-Antenna for Cognitive PMSE systems - Stöckle, Andreas; Brendel, Johannes; Rieß, Steffen; Rose, Richard; Fischer, Georg (International Conference on Wireless Information Technology and Systems, 2012)
elib2cris::1512001600,stoeckle2012
Keywords: UWB; IFA; self-complementary; UHF; ultra-wide-band; scanning antenna; SCA

A Low Insertion-Loss 10-110 GHz Digitally Tunable SPST Switch in 22 nm FD-SOI CMOS - Ciocoveanu, Radu; Weigel, Robert; Hagelauer, Amelie Marietta; Issakov, Vadim (A Low Insertion-Loss 10-110 GHz Digitally Tunable SPST Switch in 22 nm FD-SOI CMOS, 2018)
This paper presents a wideband digitally tunable SPST switch based on the travelling-wave concept that has been realized in a 22 nm FD-SOI CMOS technology. The digital control for return loss is performed through mutual inductance switching. Small-signal measurement results show that the proposed SPST switch achieves a bandwidth of 10-110 GHz, with an insertion loss of 1.2 dB at 60 GHz and a 24 dB isolation at 60 GHz, whereas large-signal measurements show a 1-dB compression point of +7 dBm at 24 GHz. Furthermore, the 3 digital control bits allow tuning return loss center frequency by approximately 7 GHz. The chip core size is 0.12 mm x 0.15 m

A Low Noise Amplifier Chain for Digital Satellite Radio Applications - Röber, Jürgen; Bänisch, Andreas; Fischer, Georg; Weigel, Robert (IEEE International Symposium on Circuits and Systems (ISCAS), 2015)
This paper contains the development and verification of low noise amplifier stages (LNA) within the framework of a front-end for digital satellite radio diversity receiver operating around 2.3 GHz. First, a low noise high gain LNA is developed to reach the high requirements of satellite radio reception. Therefore a single-ended cascode architecture is chosen. The simulated noise figure is 0.58 dB and the gain is 19.87 dB. Second, a differential stage is designed to fulfill the specification with regards to backward isolation and common-mode rejection. This circuit has a measured gain of 10.15 dB and a backward isolation of -43.24 dB. Furthermore, the two stages are combined by an integrated balun and the overall performance is verified. Due to the good noise performance of the first stage, the overall noise figure is 0.64 dB, the gain is 29.83 dB and the backward isolation is - 76.07 dB. All in all the whole circuit has a current consumption of 25.40 mA. Finally the LNA performance is compared with other state-of-the-art LNAs.
elib2cris::1512001600,roeber2015
Keywords: LNA; low noise; high gain; differential; distortion canceller; CCPDC

A Low Noise UHF Surface Transveres Wave Oscillator - Eichinger, Ludwig; Fleischmann, Bernd; Hausner, Josef; Russer, Peter; Weigel, Robert (18th European Microwave Conference, 1988, 1988)
A hybrid oscillator at 1.98 GHz has been developed using acoustic surface transverse wave (STW) delay lines operating at the third harmonic as the frequency controlling element. The STW delay lines were fabricated on 37.5° rotated Y-cut quartz substrates with a photolithographic technique. The Q value and the untuned insertion loss of the STW filters were 3400 and 21 dB, respectively. The phase noise and temperature stability of the oscillator were characterized. At a power output of 6.5 dBm a single sideband phase noise to carrier ratio of -100 dBc/Hz at 1 kHz and -70 dBc/Hz at 100 Hz was attained.
null::1512001600,eichinger1988
Keywords: Acoustic noise; Delay lines; Frequency; Insertion loss; Oscillators; Phase noise; Power harmonic filters; Surface acoustic waves

A Low Noise Vector Modulator with integrated Basebandfilter in 120 nm CMOS technology - Simon, Martin; Weigel, Robert (IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, 2003, 2003)
A low noise vector modulator for cellular systems with integrated baseband filter has been developed in 120 nm CMOS technology. The baseband filter is an anti-aliasing filter for the digital to analogue converter of the baseband that has been build around a differential amplifier with 3rd order butterworth low pass characteristic. High linearity and low output noise can be achieved for the modulator due to the current interface between the baseband filter and the mixer cells. The GSM specification for emitted noise into the receive band can be fulfilled without using a duplex filter behind the power amplifier output.
elib2cris::1512001600,simon2003
Keywords: Analog-digital conversion; Band pass filters; Baseband; CMOS technology; Differential amplifiers; Digital filters; GSM; Linearity; Power amplifiers; Power filters

A low-phase-noise monolithically integrated 60 GHz push-push VCO for 122 applications in a SiGe Bipolar technology - Chakraborty, Abhiram; Trotta, Saverio; Weigel, Robert (IEEE Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), 2013)
elib2cris::1512001600,chakraborty2013

A Low Phase-Noise SiGe Colpitts VCO with Wide Tuning Range for UWB Applications - Eßwein, Alexander; Dehm-Andone, Gunther; Weigel, Robert; Aleksieieva, Anna; Vossiek, Martin (2010 European Wireless Technology Conference (EuWIT), 2010)
An integrated differential common collector Colpitts VCO with a wide tuning range is presented in this paper. The circuit was designed and fabricated in the IHP Technologies SGB25V 250nm SiGe:C BiCMOS process. It provides a superior low phase noise performance of −115 dBc/Hz covering the frequency range of 6.7 to 8.7 GHz for UWB pulsed frequency modulated secondary radar application. An additional common collector output buffer was implemented as well. The circuit provides an overall output power of −10dBm single-ended with a power dissipation of 47mW including the on-chip buffer. This paper also shows the modifications and improvements done at the mmwave topology to reduce size and to improve the tuning range.
lhft_intern.bib::Esswein2010

A Low-Power 120-GHz Integrated Sixport Receiver Front-End with Digital Adjustable Gain in a 130-nm BiCMOS Technology - Völkel, Matthias; Hirsch, Hartmut; Dietz, Marco; Weigel, Robert; Hagelauer, Amelie Marietta; Kissinger, Dietmar (IEEE Bipolar/BiCMOS Circuits and Technology Meeting, 2017)
In this paper a 120GHz monolithic low-power sixport receiver front-end including two variable gain amplifiers, a passive sixport network, four detectors and a digital serial interface (SPI) is presented. The measurement principle is based on the additive superposition of two incident millimeter-wave signals, whereas the superposition must be fulfilled under special conditions. After power detection, the quadrature components can be extracted. The proposed measurement system is well suited for industrial radar applications, as well as for biomedical applications and it is further more well suited for communication systems. The receiver has been designed using a 0.13μm SiGe BiCMOS process from IHP (SG13G2). The whole integrated circuit has a size of 1560μm x 900μm and only consumes 102.3mW from a 3.3V supply. The receiver exhibits a 1 dB compression point of -13dBm at the center frequency. The bandwidth is 15.5 GHz and covers the lower part of the D-Band. The gain of the input amplifier can be adjusted from 3 to 16 dB by a digital interface. The maximum power consumption of the VGA is 46.2m
Keywords: industrial radar; communication receiver; interferometer; phase measurement; sixport; low power; SiGe BiCMOS; millimeter-wave

A Low-Power 14% FTR Push-Push D-Band VCO in 130 nm SiGe BiCMOS Technology with -178 dBc/Hz FOMT - Breun, Sascha; Völkel, Matthias; Schrotz, Albert-Marcel; Dietz, Marco; Issakov, Vadim; Weigel, Robert (RWW 2020, 2020)
This paper presents a low-power wideband push-push voltage controlled oscillator (VCO), achieving a frequency tuning-range (FTR) of 19 GHz (14 %) at a center frequency of 136 GHz. The VCO yields a minimum phase noise of −86.5 dBc/Hz at 1 MHz offset at a power consumption of around 27 mW from a 1.8 V supply, which yields a FOMT of −178 dBc/Hz. The chip is fabricated using a 130 nm SiGe BiCMOS technology with ft/fmax of 250 GHz/370 GHz, respectively, and is integrated with a by-32 divider chain attached to the fundamental output of the VCO, offering a 2.1 GHz output for an external phaselocked loop (PLL).<br

A Low Power 24 GHz Radar System for Occupancy Monitoring - Lurz, Fabian; Mann, Sebastian; Linz, Sarah; Lindner, Stefan; Barbon, Francesco; Weigel, Robert; Kölpin, Alexander (IEEE Radio and Wireless Symposium (RWS), 2015)
This paper presents a low power 24GHz Doppler radar system for presence detection and occupancy monitoring. It is based on a minimalistic hardware approach and is able to wirelessly sense human respiratory signals so that even non-moving persons can be detected. By intermittently measuring, the average power consumption could be significantly reduced down to e.g. 0.2mW for 20 measurements per second. Experiments verify that, due to the short wavelength, the single channel receiver limitations can be neglected when only a detection of human respiratory but no evaluation of the breathing frequency is necessary.
elib2cris::1512001600,lurz2015
Keywords: Doppler radar; low-power; occupancy sensor

A Low Power 4.3 GHz Phase-Locked Loop with Advanced Dual-Mode Tuning Technique Including I/Q-Signal Generation in 0.12 um Standard CMOS - Konstanznig, Georg; Springer, Andreas; Weigel, Robert (International Symposium on Circuits and Systems, 2003., 2003)
The design of a 4.3 GHz Integer-N (Int-N) frequency synthesizer fabricated in a 0.12 μm standard CMOS-technology for a direct conversion UMTS receiver is reported. The fully-integrated, differential, complementary, LC-tuned voltage controlled oscillator (LC-VCO) can be tuned from 4.22 GHz to 4.34 GHz with 400 kHz steps. In order to support QPSK modulation process for the UMTS receive-band (2.11 GHz - 2.17 GHz), I/Q-signals are generated using a divide-by-two stage in master-slave configuration. The proposed advanced dual-mode tuning technique is based on digital coarse-tuning with subsequent analog fine-tuning. Coarse-tuning is controlled by an additional digital logic. The latter tuning phase is done by a conventional charge pump phase-locked loop (PLL). The 2nd order loop filter is realized off-chip. Except for the VCO with 2.3 V and a current consumption of 2 mA to achieve higher output swing, the system is biased from a 1.5 V supply consuming 8 mA. Thus, the overall power consumption can be stated to be less than 17 mW. The low power consumption compares favorable with previously published synthesizers.
elib2cris::1512001600,konstanznig2003
Keywords: 3G mobile communication; Energy consumption; Frequency synthesizers; Logic; Master-slave; Phase locked loops; Power generation; Quadrature phase shift keying; Tuning; Voltage-controlled oscillators

A Low-Power 60-GHz Integrated Sixport Receiver Front-End in a 130-nm BiCMOS Technology - Völkel, Matthias; Dietz, Marco; Weigel, Robert; Hagelauer, Amelie Marietta; Kissinger, Dietmar (European Microwave Integrated Circuits Conference, 2017)
Abstract—In this paper a 60 GHz monolithic low-power sixport receiver front-end for high precision industrial radar systems is presented. The measurement principle is based on the passive superposition and power detection of two incident millimeterwave signals. The integrated receiver has been designed using a 0.13μm SiGe BiCMOS process from IHP (SG13G2) and includes a low noise amplifier (LNA), the passive sixport structure and four detectors. The signal processing in the baseband is done with an ADC-board designed with components from Texas Instruments and a Cyclone IV FPGA board. The integrated receiver circuit has a size of 1320μm x 950μm and a low power consumption of 73mW from a 3.3V supply.
Keywords: industrial radar; interferometer; phase measurement; sixport; low power; SiGe BiCMOS

A low power CMOS transmitter with Class-E power amplifiers for positioning application in multi-band - Hsieh, Chia-Yu; Röber, Jürgen; Bänisch, Andreas; Hagelauer, Amelie Marietta; Ußmüller, Thomas; Weigel, Robert (GeMiC 2016, German Microwave Conference 2016, 2016)
In this paper, a transmitter for outdoor positioning application such as animal tracking is introduced. Class-E power amplifiers are exploited in the transmitter system in order to increase the energy efficiency for the demand of long operation duration of the system. Along with the need of power saving, a circuit topology is proposed to realize the modulation based on Binary Offset Carrier (BOC) technique at two different bands to achieve higher positioning accuracy and better utilization of the spectrum by transmitting data simultaneously. The operating frequencies of the system are 868 MHz and 2.4 GHz, and the circuit is designed in 150nm CMOS technology. The power efficiency of the class-E power amplifier is greater than 50 % over 2.4-2.8 GHz while the measured output power is greater than 10 dBm from 1.3 to 2.8 GHz.
elib2cris::1512001600,hsieh2016
Keywords: positioning; class-E

A Low-Power Embedded Communication Platform for Medical Applications - Schwarzmeier, Andre; Reuter, Lukas Michael; Mena-Carrillo, Juan; Weber, Werner; Fischer, Georg; Weigel, Robert; Kissinger, Dietmar (46th annual conference of the German Society for Biomedical Engineering, 2012)
Introduction This paper presents a scalable, flexible and energy efficient embedded communication platform for seamless data transfer of medical sensor signals from the sensor acquisition point to a medical service centre. The presented platform can be used as an assistance system for improved medical support and care of patients and lifestyle users by providing vital parameter data to the service centre for a variety of individual assistance services. Methods The presented hardware platform is comprised of two functional blocks. A sensor platform has been implemented containing a medical device controller for collection of the data of various medical sensors connected via an analog front end or by an integrated Bluetooth transceiver module. Furthermore, a communication module including an A-GPS receiver enables GSM and UMTS data and voice connections to a central infrastructure and provides positioning data of the patient current location. The software protocol stack for the sensor data transmission is kept flexible in order to allow different communication standards. Special emphasis has been put on the energy management concept to optimize the battery life time and increase patient acceptance. Results The modular hardware and software co-design allows the connection of a wide range of different medical sensors, adjusted to the patient needs and specific use case. The use of data reduction and pre-processing techniques allows a reduction of the amount of data transferred to the infrastructure. Additionally, the centralized aggregation of sensor data enables short transmission times. This, in conjunction with an application specific energy management concept, leads to an increased battery life time. Conclusion The presented platform allows the collection of vital parameters from a variety of medical sensors for personal assistance of patients and elderly people. This concept allows new possibilities in diagnosis and treatment with the goal of an increased quality of life through the extension of independent at-home living periods.
elib2cris::1512001600,schwarzmeier2012
Keywords: Medical; Platform; Energy; Budget

A Low-Power Fall Detection and Activity Monitoring System for Nursing Facilities and Hospitals - Schwarzmeier, Andre; Weigel, Robert; Fischer, Georg; Kissinger, Dietmar (IEEE Topical Conference on Bio-medical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS2014), 2014)
Abstract— This paper presents a fall detection and activity monitoring system comprised of a server software for data management, multiple UHF RFID readers and an energy efficient, small and lightweight semi-passive UHF RFID sensor tag. The system is able to gather activity and indoor localization data of several persons wearing just one sensor tag, making it particularly suitable for the use in nursing facilities or hospitals. The implemented fall detection alerts nursing staff in case of a detected fall and allows quick intervention in case of an emergency.
elib2cris::1512001600,schwarzmeier2013
Keywords: Index Terms— semi active UHF RFID; remote fall monitoring; sensor tag; localization; Ambient Assisted Living (AAL); sensor processing

A Low-Power Integrating and Sampling Demodulator for 3-5 GHz IR-UWB Applications - Schrüfer, Daniel; Röber, Jürgen; Schwarzkopf, Artur; Rabenstein, Thomas; Mai, Timo; Weigel, Robert (2021 IEEE Radio and Wireless Symposium (RWS), 2021)

A low-power, low-noise, highly-linear receiver for 122 GHz applications in a SiGe BiCMOS technology - Chakraborty, Abhiram; Trotta, Saverio; Aufinger, Klaus; Lachner, Rudolf; Weigel, Robert (IEEE Radio and Wireless Symposium (RWW), 2014)
elib2cris::1512001600,chakraborty2014

A Low-Power Low-Noise Single-Chip Receiver Front-End for Automotive Radar at 77 GHz in Silicon-Germanium Bipolar Technology - Hartmann, Marcus; Wagner, Christoph; Seemann, Kay; Platz, Johannes; Jäger, Herbert; Weigel, Robert (IEEE Radio Frequency Integrated Circuits Symposium, 2007)
This paper presents a single chip receiver front-end, including low-noise amplifier and mixer, for application in automotive radar systems at 77 GHz. The circuit has been implemented in a SiGe HBT technology. The complete circuit occupies 1030 times 1130 mum2 including bond pads and dissipates 440 mW from a 5.5 V supply. The front-end shows a minimum measured single sideband noise figure (SSB NF) of 11.5 dB and a maximum conversion gain of 30 dB at 77 GHz. Linearity measurements show a 1 dB input compression point of -26 dBm and a third order intercept point of -21.6 dBm at 77 GHz.
elib2cris::1512001600,hartmann2007a

A Low-Power Micromixer with High Linearity for Automotive Radar at 77 GHz in Silicon-Germanium Bipolar Technology - Hartmann, Marcus; Wagner, Christoph; Seemann, Kay; Platz, Johannes; Jäger, Herbert; Weigel, Robert (Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, 2007)
A direct-conversion micromixer realized in a modern SiGe:C bipolar technology for application in automotive radar systems at 77 GHz is presented. The mixer exhibits a minimum conversion gain of 15 dB and a maximum noise figure of 16.5 dB over a frequency range from 75 GHz to 85 GHz. The 1dB input related compression point is at -3dBm and the RF and LO matching is better than -20 dB and -10 dB, respectively. The total DC current consumption is 34 mA at 5.5 V
elib2cris::1512001600,hartmann2007

A low-power multi-standard frontend for wireless sensor networks - Essel, Jochen; Brenk, Daniel; Heidrich, Jürgen; Hofer, Günter; Holweg, Gerald; Weigel, Robert (IEEE Sensors2010, 2010)
This paper presents a low-power multi-standard frontend for passive wireless RFID based sensor networks. The CMOS only frontend is implemented in a 0.13 μm CMOS technology. It includes a highly efficient rectifier for UHF and HF to supply the digital logic, the integrated sensor interface and the necessary auxiliary circuits like a low-power voltage/current reference and the local oscillator. Furthermore the complete sensor enhanced RFID transponder is able to communicate with a standard EPC HF and UHF RFID reader. The DC power consumption of the analog frontend components is about 3 μA. The measured overall RF-to-DC power conversion efficiency of the complete analog frontend for a DC output power of 10 μW is about 17% at -11 dBm RF input power for UHF. To the authors' knowledge, this is the highest UHF efficiency achieved by a multi-standard sensor tag. The efficiency of the HF frontend at -4 dBm RF input power and 1 V VDD is about 10%. The maximum efficiency of the frontend is about 17% at HF.
elib2cris::1512001600,essel2010a
Keywords: CMOS integrated circuits; UHF oscillators; low-power electronics; radiofrequency identification; rectifiers; wireless sensor networks

A low power Pulse Frequency Modulated UWB radar transmitter concept based on switched injection locked harmonic sampling - Carlowitz, Christian; Eßwein, Alexander; Weigel, Robert; Vossiek, Martin (7th German Microwave Conference (GeMiC2012), 2012)
Pulse Frequency Modulated ultra-wideband (PFM-UWB) radar signals have been introduced as a very capable option for UWB ranging and wireless local positioning. PFM-UWB signals allow for simple correlating receivers and for a very efficient use of the UWB spectral mask. The generation of pulse frequency modulated (PFM) ultra-wideband (UWB) signals usually requires a fast tunable RF-VCO and good linear RF amplifiers. The resulting complexity and power consumption of a PFM-UWB transmitter can be considered as a drawback compared e.g. to simple impulse radio UWB systems. In this paper, a PFM UWB transmitter concept is introduced that overcomes these drawbacks. The novel approach is based on harmonic sampling with a switched injection locked oscillator (SILO). RF signal generation is solely based on a very simple fixed frequency pulsed LO that samples the phase of an injected harmonic of a baseband FM signal. In this paper the basic concept for switched injection locked harmonic sampling PFM UWB signal generation is introduced and its feasibility is proved through measurements with a 7-8 GHz PFM UWB transmitter prototype.
lhft_intern.bib::Carlowitz2012

A low-power rram memory block for embedded, multi-level weight and bias storage in artificial neural networks - Pechmann, Stefan; Mai, Timo; Potschka, Julian; Reiser, Daniel; Reichel, Peter; Breiling, Marco; Reichenbach, Marc; Hagelauer, Amelie (Micromachines, 2021)
Pattern recognition as a computing task is very well suited for machine learning algorithms utilizing artificial neural networks (ANNs). Computing systems using ANNs usually require some sort of data storage to store the weights and bias values for the processing elements of the individual neurons. This paper introduces a memory block using resistive memory cells (RRAM) to realize this weight and bias storage in an embedded and distributed way while also offering programming and multi-level ability. By implementing power gating, overall power consumption is decreased significantly without data loss by taking advantage of the non-volatility of the RRAM technology. Due to the versatility of the peripheral circuitry, the presented memory concept can be adapted to different applications and RRAM technologies.
CRIS-Team Scopus Importer:2021-11-05
Keywords: ANN; Embedded memory; Low-power; Memory block; Multi-level; RRAM

A Low Power SiGe HBT LNA For UWB Applications - Hamouda, Mohammed; Fischer, Georg; Weigel, Robert; Ußmüller, Thomas (German Microwave Conference, 2012)
A low noise amplifier (LNA) is implemented in this work for ultra wide band (UWB) localization and sensing systems within a wide frequency range starting from 400MHz and up to 10GHz. The topology used is a resistive shunt feedback and a peaking inductance in series with the output transistor to achieve the desired bandwidth and have better noise performance. The LNA is fabricated in low cost 0.25μm 92GHz fmax SiGe-HBT BiCMOS process technology. The area of the manufactured chip is 0.73mm2. The achieved gain is 12dB with a NF less than 3.7dB over the entire frequency range while the consumed power is only 14.5mW.
elib2cris::1512001600,hamouda2012a

A Low-Power Squaring Circuit with Regulated Output and Improved Settling Time in 180 nm CMOS for 3-5 GHz IR-UWB Applications - Schrüfer, Daniel; Rober, Jürgen; Mai, Timo; Weigel, Robert (Advances in Radio Science : Kleinheubacher Berichte, 2021)
This paper demonstrates a low-power squaring circuit for 3-5 GHz non-coherent Impulse-Radio Ultra-Wideband (IR-UWB) receivers for Pulse Position Modulation (PPM) in a low-cost 180 nm CMOS technology. The squaring, which is the key element in typical IR-UWB receivers, is performed exploiting the non-linear transfer function of a MOS transistor. For a high gain at low power consumption the transistor is biased in the moderate inversion region, where the second-order derivative of the transconductance g(m) and, as a result, the quadratic term in the transfer function reaches a maximum. A control loop was implemented to set the dc output voltage to a defined value and thus to allow a comparison of the squarer output signal with a defined threshold voltage, which can easily be set and adjusted (e.g. by a DAC). To speed up the settling time of the output and hence to reach higher data rates, a novel slew-rate booster is implemented at the output. Thereby, the squarer is capable of data rates of up to 15.6 Mbits(-1), which is more than two times higher compared to the circuit without the slew-rate booster, while only consuming 72.4 mu W in addition. In the extracted post-layout simulations the whole circuitry consumes 724 mu A at a 1.8 V power supply, resulting in a power consumption of 1.3 mW.
CRIS-Team WoS Importer:2021-12-31

A Low-Power Wideband D-Band LNA in a 130 nm BiCMOS Technology for Imaging Applications - Aguilar Mendoza, Erick; Hagelauer, Amelie Marietta; Kissinger, Dietmar; Weigel, Robert (Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, 2018)
A Low-power D-Band Low Noise Amplifier (LNA) manufactured in a recent 130 nm SiGe BiCMOS process for imaging applications is presented. The architecture consists of an optimized 3-stage cascode amplifier which achieves a maximum gain of 32.8 dB and a gain>20 dB in the frequency range from 121 to 161 GHz with a DC power consumption of 39.6 mW. The simulated noise figure varies from 6 to 9.7 dB within the range 130 to 140 GHz. To the best of the author’s knowledge, the presented work exhibits the highest gain-bandwidth product with the lowest power consumption for a D-Band amplifier in a 130 nm SiGe technology.
Keywords: D-Band; Imaging; Radiometrie; LNA; SiGe; mm-wave

A Low-Voltage Broadband D-Band BPSK Modulator for a PMCW Radar Transmitter in 22 nm FDSOI - Engelmann, Andre; Probst, Florian; Hetterle, Philip; Weigel, Robert; Dietz, Marco (Asia-Pacific Microwave Conference 2022 (APMC), 2022)
This work presents a broadband low-voltage binary-phase-shift-keying (BPSK) modulator operating in the D-band. The modulator is intended for a phase-modulated continuous-wave (PMCW) radar transmitter with a chip rate of up to 12.5 Gb/s and integrated into an advanced 22 nm fully-depleted silicon-on-insulator (FDSOI) technology. The circuit covers a bandwidth of 34 GHz at a carrier frequency of 140 GHz with a maximum conversion gain of 2.5 dB. A 1 dB output compression point of −7.2 dBm is reached while consuming 27 mW DC-Power at a supply voltage of only 0.8 V and a circuit core area of 0.051 sqm
Keywords: Binary-phase-shift-keying (BPSK) modulator; CMOS; D-band; FDSOI; MMIC; phase-modulated continuous-wave (PMCW) radar.

A Low Voltage Folded Gilbert Cell Mixer for 6G Communication Systems - Hetterle, Philip; Engelmann, Andre; Probst, Florian; Huang, Tianzhu; Weigel, Robert (Asia-Pacific Microwave Conference (APMC), 2023)
This paper presents the design of a folded Gilbert cell D-band down-conversion mixer manufactured in a 22 nm fully-depleted silicon-on-insulator (FDSOI) CMOS technology. The mixer runs on a supply voltage of 800 mV and consumes a power of 28 mW. The device achieves a conversion gain of -7 dB while maintaining a broad bandwidth of 30 GH
Keywords: CMOS; D-band; FDSOI; Gilbert cell; down-conversion; low voltage; mixer; mm-wave; mobile communication; 6G

A Machine Learning Perspective on Automotive Radar Direction of Arrival Estimation - Fuchs, Jonas; Gardill, Markus; Lübke, Maximilian; Dubey, Anand; Lurz, Fabian (IEEE Access, 2022)
Millimeter-wave sensing using automotive radar imposes high requirements on the applied signal processing in order to obtain the necessary resolution for current imaging radar. High-resolution direction of arrival estimation is needed to achieve the desired spatial resolution, limited by the total antenna array aperture. This work gives an overview of the recent progress and work in the field of deep learning based direction of arrival estimation in the automotive radar context, i.e. using only a single measurement snapshot. Additionally, several deep learning models are compared and investigated with respect to their suitability for automotive angle estimation. The models are trained with model- and data-based approaches for data generation, including simulated scenarios as well as real measurement data from more than 400 automotive radar sensors. Finally, their performance is compared to several baseline angle estimation algorithms like the maximum-likelihood estimator. All results are discussed with respect to the estimation error, the resolution of closely spaced targets and the total estimation accuracy. The overall results demonstrate the viability and advantages of the proposed data generation methods, as well as super-resolution capabilities of several architectures.
CRIS-Team WoS Importer:2022-02-04

Ambient Environmental Parameter Estimation for Reliable Diffusive Molecular Communications - Toriyama, Shota; Hasegawa, Shoma; Kirchner, Jens; Fischer, Georg; Anzai, Daisuke (Future Internet, 2022)
Molecular communication is a promising communication technology that uses biomolecules such as proteins and ions to establish a communication link between nanoscale devices. In diffusive molecular communication, which uses diffusion characteristics of transfer molecules, the diffusion mechanism is mathematically derived as a Channel Impulse Response (CIR) to design an optimal detector structure. However, an ideal environment is assumed for deriving a CIR. Hence there is a concern that developed systems based on the derived CIR may not operate well in a realistic environment. In this study, based on the finite element method (FEM), we constructed a model of the environment with heterogeneous temperature distribution and actual volume of transmitting molecules to not only demodulate the bit information via maximum likelihood sequence estimation (MLSE) but also to estimate the temperature and volume of the transmitting molecules. Furthermore, in this study, we evaluated the performance of the MLSE method and investigated the effects of ambient environmental temperature distribution and volume of the transmitted molecules on diffusive molecular communication. The evaluation results demonstrated that the proposed method can improve the communication performance by approximately 9 by estimating the temperature and transmit molecule volume.
Keywords: diffusive molecular communications; MLSE; ambient environmental parameter estimation

A measurement method to mitigate temperature effects in nanometer CMOS RF power amplifiers - Oßmann, Patrick; Fuhrmann, Jörg; Moreira, José; Pretl, Harald; Springer, Andreas (Microelectronics (Austrochip), 22nd Austrian Workshop on, 2014)

A Memoryless Semi-Physical Power Amplifier Behavioral Model Based on the Correlation Between AM-AM and AM-PM Distortions - Glock, Stefan; Rascher, Jochen; Sogl, Bernhard; Ußmüller, Thomas; Müller, Jan-Erik; Weigel, Robert (IEEE Transactions on Microwave Theory and Techniques, 2015)
A new semi-physical memoryless computationally effective behavioral model (BM) capable of predicting amplitude-modulation-to-amplitude-modulation (AM-AM) and amplitude-modulation-to-phase-modulation (AM-PM) distortions is proposed. In recent years, AM-AM and AM-PM distortions have been separately studied in literature. Here, we investigate the correlation between AM-AM and AM-PM distortions first. Based on the observed correlation, a novel AM-PM model is derived from the well-known Rapp AM-AM model. On the basis of the close relationship between the AM-AM and AM-PM model, a highly accurate and computationally effective large-signal BM is obtained. The newly developed model addresses the current needs of the mobile industry that requires BMs of the power amplifier (PA), which can be interpreted by the designers. In addition, the models must be computationally effective due to the limited computation power in mobile handset. Therefore, only memoryless BMs can be taken into account and larger errors are accepted for the sake of computational effectiveness. In this paper, it is shown that the newly introduced model achieves excellent results, when it is applied to actual industrial applications of two GaAs-based class-AB PAs in 65-nm technology and one CMOS-based class AB PA in 28-nm technology, which are designed for mobile communications.
elib2cris::1512001600,glock2015

A MEMS-Based Reconfigurable RF Receiver Front-End Utilizing Multi-Port Technology - Mack, Torsten (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2005)

A Method for Accurate Modeling of BAW Filters at High Power Levels - Tag, Andreas; Chauhan, Vikrant; Huck, Christian; Bader, Bernhard; Karolewski, Dominik; Pitschi, Maximilian; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2016)
elib2cris::1512001600,tag2016

A method for the analysis of ramp-inherent linearity distortions in automotive radar applications - Müller, Felix; Steinbuch, Dirk; Walter, Thomas; Weigel, Robert (German Microwave Conference (GeMiC), 2015)
Through the use of sensors to provide information about the vehicles surroundings, driver assistance systems increase traffic safety. These sensors must not deliver wrong data due to noise or external distortion. In FMCW Radar systems additionally a highly linear ramp is essential. Hence nonlinear ramps have direct impact on the baseband spectrum. Weak targets could be covered and therefore not detected. This paper describes a method for evaluating the RF ramp linearity, based on analysis of the baseband signal. Therefore the analysis is easier, as the baseband frequency is only a few MHz depending on chirp modulation parameters and target distance. The instantaneous frequency is measured, so that deviations from the ideal slope can be detected immediately. Results are compared with simulations and high frequency measurements with a commercial availably spectrum analyzer which calculates the mean frequency deviation over a high number of ramps.
elib2cris::1512001600,mueller2015

A Method for the Determination of the Complex Permittivity by Detuned Ring Resonators for Bulk Materials up to 110 GHz - Talai, Armin; Steinhäußer, Frank; Bittner, Achim; Schmid, Ulrich; Weigel, Robert; Kölpin, Alexander (International Journal of Microwave and Wireless Technologies, 2015)
elib2cris::1512001600,talai2015

A Method to Determine the Injected Real Power into an IC Pin in Case of a Conducted Immunity EMC Test - Weigel, Robert; Frick, Marco; Eidher, R. (IEEE International Symposium on Electromagnetic Compatibility, 2011)
The direct power injection (DPI) measurement method is an internationally accepted technique to verify the robustness of an integrated circuit (IC) against an injected RF signal. The requirements of this measurement method respecting the setup is fixed in the international standard IEC 62132-4 [1]. In this paper a method is presented which allows to determine the real power injection into the IC pin by considering the influence of the required test printed circuit board (PCB). To apply this method only the transmitted and reflected RF power, the voltage standing wave ratio (VSWR), which are already locked during the DPI test, and the scattering parameters (S-parameters) of the PCB injection path are needed. How to use the available measurement results and how to determine the required S-parameters of the PCB injection path is described in this paper.
elib2cris::1512001600,weigel2011e
Keywords: S-parameters; electromagnetic compatibility; integrated circuit testing; printed circuits; IC Pin; S-parameters; conducted immunity EMC test; injected real power

A Microstrip Resonant Biosensor for Aqueous Glucose Detection in Microfluidic Medical Applications - Schwerthöffer, Udo; Warter, Christoph; Weigel, Robert; Kissinger, Dietmar (2014 IEEE Topical Conference on Bio-medical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS2014), 2013)
elib2cris::1512001600,schwerthoeffer2013b

A Microwave Interferometer Based Contactless Quasi-TEM Waveguide Position Encoder with Micrometer Accuracy - Mann, Sebastian; Lindner, Stefan; Lurz, Fabian; Barbon, Francesco; Linz, Sarah; Weigel, Robert; Kölpin, Alexander (IEEE MTT-S International Microwave Symposium (IMS), 2014)
Position measurement plays an important role in industrial process technology. Hereby, a waveguide based position sensor system for industrial applications is described. The proposed system features a Phase Locked Loop controlled 24 GHz signal source, an interferometric Six-Port receiver structure, a radar coupler, and a terminated quasi-TEM parallel plate waveguide structure. Furthermore, the system concept comprises a target, which can be applied both touching and contactless in the waveguide’s fringing field, reflecting a part of the transmitted wave. To obtain the target’s position information, the reflected wave is compared to a reference signal with respect to the relative phase difference. Hence, this phase shift is directly related to the position information.
elib2cris::1512001600,mann2014a
Keywords: Six-Port; position encoder; parallel plate waveguide; phase measurement

A microwave permittivity sensing system based on a hybrid heterodyne reflectometer circuit - Nehring, Johannes; Schütz, Martin; Weigel, Robert; Kissinger, Dietmar (Microwave Conference (EuMC), 2014 44th European, 2014)

A Microwave Sensing System for Aqueous Concentration Measurements based on a Microwave Reflectometer - Hofmann, Maximilian; Trenz, Florian; Weigel, Robert; Fischer, Georg; Kissinger, Dietmar (2012 IEEE MTT-S International Microwave Symposium Digest (MTT), 2012)
This paper presents a novel parameterized Debye relaxation model for aqueous glucose solutions up to 40 GHz. The influence on all Debye relaxation parameters is given by three equations. A compact microwave demon- strator for concentration measurements, consisting of two directional couplers, a voltage controlled oscillator (VCO), a six-port-junction, power detectors and a signal processing board is introduced. A hybrid calibration procedure for the reflectometer based approach is applied, based on a linear five standard calibration and a three standard error-box model, respectively.
elib2cris::1512001600,hofmann2012c
Keywords: Diabetes; Electromagnetic reflection; Relaxation methods

A Microwave VNA for Biomedical In-line Concentration Measurements - Hofmann, Maximilian; Bauch, Andreas; Weigel, Robert; Fischer, Georg; Kissinger, Dietmar (BioWireless Conference, 2013)
This paper presents a microwave (MW) test-set designed for biomedical in-line concentration measurements. The demonstrator consists of a commercial voltage controlled oscillator (VCO) with an output power of up to +12.0 dBm, feeding an asymmetric 4 way power divider. A fraction of 0 dBm of the VCO output is driving three I-Q mixers, which realizes a homodyne vector network analyzer. Dual directional couplers were investigated concerning the application for concentration measurements. A wiggly line coupler was separately fabricated and measured as well as implemented in the demonstrator. The entire system is fabricated, calibrated and subsequently characterized with a transmission based permittivity sensor.
elib2cris::1512001600,hofmann2013a

A millimeter-wave FMCW radar system simulator for automotive applications including nonlinear component models - Dudek, Manuel; Kissinger, Dietmar; Weigel, Robert; Fischer, Georg (European Radar Conference (EuRAD), 2011)
A fully differential millimeter wave frequency modulated continuous wave (FMCW) radar architecture is built up in Agilent's RF design and system simulation environment ADS® to investigate the influence of RF impairments on system level on the target signal. To take also the surroundings of the automotive scenario into account a 3D ray tracing channel simulator is coupled in a Matlab® co-simulation providing realistic data of the traffic situation. Therefore investigations on the performance of the radar frontend in an automotive long range radar (LRR) application are enabled, the functionality of the circuitry can be verified and components designed in the most beneficial way, so that the best performance is achieved with the available resources. For nonlinear behavior the frontend components are parameterized according to recently published values for 77GHz SiGe circuits. The functionality of the complete simulation environment is demonstrated by calculating a typical traffic situation.
elib2cris::1512001600,dudek2011c

A MIM-cap free digitally tunable NMOS pi-network - Thomas, Anthony; Bakalski, Winfried; Ußmüller, Thomas; Weigel, Robert (IEEE Radio and Wireless Symposium (RWW), 2014)
elib2cris::1512001600,thomas2014

A Miniaturized Very Low-Power Vector Modulated CMOS Phase Shifter for Wireless Receivers - Kastenhuber, Tina; Röber, Jürgen; Bänisch, Andreas; Fischer, Georg; Weigel, Robert (German Microwave Conference, 2015)
This paper presents and analyses a phase shifter for diversity receivers, which modulates the I-/Q-vector in the constellation diagram. The system consists of a three stage programmable gain amplifier (PGA) chain in both branches. The design covers the full phase range of 360◦. Each stage can be programmed to amplify the incoming signal between 19 dB and 63 dB with a centre frequency of 3MHz. The radio frequency (RF) signal is down-converted to an intermediate frequency (IF) of 5MHz, where phase shifting is done. The circuit is intended for an automotive satellite radio receiver in S- and L-band. Thus, demand automotive requirements have to be fulfilled. The supply voltage is 1.8V. Compared to other phase shifters, the power consumption of 2.7mW is highly energyefficient. This system includes a constant gm-source and a biasing circuit. All requirements are verified in post-layout Corner and Monte−Carlo analysis using Virtuoso and WiCkeD. The design only takes 0.116 mm2 of silicon area in a 150- nm CMOS technolog
elib2cris::1512001600,kastenhuber2015
Keywords: Phase shifter; vector modulated; PGA; constant gm-source; low-power; diversity

A mobile microcontroller platform for sensor fusion and communication - Reuter, Lukas Michael; Agethen, Roman; Lurz, Fabian; Fischer, Georg; Weigel, Robert; Kissinger, Dietmar (Embedded World Conference, 2012)
elib2cris::1512001600,reuter2012

A Modular MIMO Millimeter-Wave Imaging Radar System for Space Applications and Its Components - Hrobak, Michael; Thurn, Karsten; Moll, Jochen; Hossain, Maruf; Shrestha, Amit; Thualfiqar, Al-Sawaf; Stoppel, Dimitri; Weimann, Nils G.; Rämer, Adam; Heinrich, Wolfgang; Martinez, Javier; Vossiek, Martin; et al. (Journal of Infrared, Millimeter, and Terahertz Waves, 2020)
This article presents the design and prototyping of components for a modular multiple-input-multiple-output (MIMO) millimeter-wave radar for space applications. A single radar panel consists of 8 transmitters (TX) and 8 receivers (RX), which can be placed several times on the satellite to realize application-specific radar apertures and hence different cross-range resolutions. The radar chirp signals are generated by SiGe:C BiCMOS direct-digital-synthesizers (DDS) in the frequency range of 1 to 10.5GHz with a chirp repetition rate of <1μs within each TX and RX. The latter allows for easy interfaces in the MHz range in between the TX/RX units and therefore optimized 2-D sparse antenna arrays with rather large distances in between the TX/RX antennas. Furthermore, this allows for ideally linear frequency modulated continuous-waveforms (FMCW) in conjunction with phase-shift-keying (PSK) radar signals and enables simultaneous operation of all TX when code division multiplex (CDMA) modulation schemes are applied. Comparably low complexity of the TX/RX units has been achieved by applying straightforward frequency plans to signal generation and detection but comes with challenging requirements for the individual active and passive components. Tackled by thin film technology on alumina and the recently developed SiGe and InP semiconductor technologies, which have been further optimized in terms of process maturity and space qualification. Upconversion and downconversion to and from 85 to 94.5GHz are performed by double balanced Gilbert mixers realized with InP double heterojunction bipolar transistor technology (DHBT) and 42-GHz local oscillator signals from SiGe:C BiCMOS VCO synthesizer using phase-locked-loops (PLL). InP DHBT power amplifiers and low-noise amplifiers allow for output power levels of 15dBm and >30dB gain with noise figure values of 9dB, respectively. The MIMO radar utilizes patch antenna arrays on organic multilayer printed circuit boards (PCB) with 18dBi gain and 18∘ half power beamwidth (HPBW). Generation of power supply and control signals, analog-to-digital conversion (ADC), and radar signal processing are provided centrally to each panel. The radar supports detection and tracking of satellites in distances up to 1000m and image generation up to 20m, which is required to support orbital maneuvers like satellite rendezvous and docking for non-cooperative satellites.

A Modular Vector Field Measurement System at 150 GHz, 300 GHz and 450 GHz - Hofmann, A.; Seibert, Günter; Manglberger, M.; Kalb, A.; Göbel, S.; Yao, S.; Weinzierl, Jochen; Schmidt, Lorenz-Peter; Brand, Hans (Proceedings of GeMiC, April, 2005)
UnivIS-Import:2015-04-16:Pub.2005.tech.IE.LEH.amodul

A Molecular Communication Testbed Based on Proton Pumping Bacteria: Methods and Data - Grebenstein, Laura; Kirchner, Jens; Wicke, Wayan; Ahmadzadeh, Arman; Jamali Kooshkghazi, Vahid; Fischer, Georg; Weigel, Robert; Burkovski, Andreas; Schober, Robert (IEEE Transactions on Molecular, Biological and Multi-Scale Communications, 2019)
This paper presents a detailed description of a recent biological molecular communication (MC) testbed and provides a set of experimental measurement data. In particular, the MC testbed is realized using Escherichia coli (E. coli) bacteria that express the light-driven proton pump gloeorhodopsin (GR) from Gloeobacter violaceus (G. violaceus). Upon an external light stimulus, these bacteria (as the transmitter) export protons (as the signaling molecules) into the channel. This changes the pH level of the environment, which can be detected with a pH sensor (as the receiver). To facilitate future advancement in the experimentation of MC systems, in this paper, we explain the methodology used for the development of our testbed and discuss the reasoning behind the choices made throughout its evolution. Moreover, we provide different categories of measurement data obtained with the testbed. The data set is expected to facilitate and promote the experimental evaluation of communication schemes developed by the MC community.
CRIS-Team Scopus Importer:2021-04-20

Amplitude Modulation in a Molecular Communication Testbed with Superparamagnetic Iron Oxide Nanoparticles and a Micropump - Bartunik, Max; Thalhofer, Thomas; Wald, Christian; Richter, Martin; Fischer, Georg; Kirchner, Jens (Body Area Networks. Smart IoT and Big Data for Intelligent Health. BODYNETS 2020. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, vol 330., 2020)
Keywords: molecular communication; nanoparticles; amplitude modulation

A Multiband 2-Port Vector Network Analyzer based on Six-Port Junctions for Biomedical Measurement Applications between 6 GHz and 33 GHz - Linz, Sarah; Hofmann, Maximilian; Fischer, Georg; Weigel, Robert; Kissinger, Dietmar (2013 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC), 2013)
Concentration measurements of dissolved substances in fluids are of great interest for biomedical as well as industrial applications. In this work a multiband vector network analyzer is presented that is capable of determining phase variations due to changes in the concentration. A topology comprising two Six-Port networks optimized for the frequencies 6.6 GHz, 19.7GHz and 32.4GHz has been implemented. Measurement results show a characteristic change of the phase when increasing the glucose concentration in binary aqueous solutions.
elib2cris::1512001600,linz2013
Keywords: Six-Port; multiband

A Multiband 2-Port VNA for Biomedical Applications based on two Six-Port-Junctions - Hofmann, Maximilian; Linz, Sarah; Weigel, Robert; Fischer, Georg; Kissinger, Dietmar (2013 IEEE MTT-S International Microwave Symposium Digest (IMS), 2013)
This paper presents a triple band two port vector network analyzer (VNA) consisting of two six-port-junctions for biomedical concentration measurements. The microwave sensing system is designed to operate with a 10% bandwidth around 6.6 GHz, 19.7 GHz and 32.4 GHz. An embedded coplanar permit- tivity sensor will be applied for measurements of aqueous glucose solutions. The entire microwave sensing system is designed, fab- ricated and characterized with different glucose concentrations in binary solutions.
elib2cris::1512001600,hofmann2013c

A multichannel scanning receiver system for surveillance applications - Hausknecht, Frank; Mzyk, Raphael; Dehm-Andone, Gunther; Fischer, Georg; Weigel, Robert (6th Future Security Research conference, 2011)
elib2cris::1512001600,hausknecht2011
Keywords: Multichannel; scanning; Receiver; surveillance

A Multi-Functional Reconfigurable Low-Power Ultra-High PSRR CMOS Reference-System - Söll, Christopher; Bänisch, Andreas; Röber, Jürgen; Shi, Lan; Weigel, Robert (IEEE Conference on PhD Research in Microelectronics and Electronics (PRIME), 2015)
This paper presents a new reference system with emphasis on low power design and high power supply rejection. The untrimmed reference provides a 600mV output voltage, which only differs by 5.75mV in the temperature range between -40 ◦ C and +125 ◦ C and a PSRR of -157.2 dB at 10Hz. The core part of the reference produces a reference potential of 416.1mV with a deviation of only 1.59mV. Moreover, the circuit provides a 900mV output, a temperature independent 3 μA current and trimming possibilities for the temperature curves and the amplitude of output voltages and currents. Under all operating conditions, the post-layout Corner- and Monte-Carlo-Simulations show a power consumption of less than 40 μA and ensure functionality across process, supply voltage and temperature variations.
elib2cris::1512001600,soell2015
Keywords: bandgap; reference; low power; high psrr; temperature coefficient; subregulation; GRK-1773

A Multi-Layer Perceptron Applied to Number of Target Indication for Direction-of-Arrival Estimation in Automotive Radar Sensors - Gardill, Markus; Fuchs, Jonas; Frank, Christian; Weigel, Robert (2018 IEEE 28th International Workshop on Machine Learning for Signal Processing (MLSP), 2018)
Keywords: Automotive Radar; Direction-of-Arrival Estimation; Neural Network; Multi-Layer Perceptron

A Multilayer Reconfigurable Transmitarray in K-Band for Beam Steering Applications - Frank, Martin; Weigel, Robert; Kölpin, Alexander (International Conference on Electromagnetics in Advanced Applications (ICEAA 2017), 2017)
There are many different radar applications which require a change in the direction of the radiation beam, for example in order to separate signals coming from different directions or to track targets. A change in the main beam direction is usually realized by a mechanical rotation of the antenna or electronically by using phased array systems. The work presented in this paper is focused on a less common approach to realize beam steering functionality, the so called transmitarray. The transmitarray is built of several unit cells and is placed in front of a focal source. Each unit cell includes two radiation structures to receive the signal coming from the source on one side and to retransmit it on the other side with a distinct phase shift. The superposition of the signal contributions of all array elements leads to a certain radiation pattern of the whole structure. By individually adjusting the phase shifts of each unit cell the desired radiation pattern can be realized. The realization of a transmitarray can be done in two steps. First the design of a unit cell which provides the capability of performing the phase shifts has to be done. Afterwards the array synthesis is done by combining several unit cells. The unit cell used in this approach is derived from previous research with significant improvements and is supposed to work in the 24 GHz ISM band. A continuous phase range is obtained by loading patches with varactor diodes on the outer layers of a layer stack consisting of two thin laminates of RO4350 and a metal sheet in between. Both, metal sheet and second metal layer of the laminate have apertures inside to provide coupling from one patch to the other. By applying a voltage difference between patch and ground plane the capacity of the varactor diode is changed. This detunes the whole structure and leads to a change in the transmission phase. To obtain the desired continuous phase range of 360° several unit cells are placed in series resulting in a multilayer structure. The functionality of the designed unit cell has been verified in simulation and measurement. In the next step a 5 x 1 array has been synthesized and designed for a +/- 30° beam steering range with CST MWS. Measurements of the radiation pattern for several combinations of the five tuning voltages have been performed with a measurement setup consisting of two horn antennas and a rotation stage. A +/- 30° beam steering range has been successfully confirmed. The designed transmitarray at 24 GHz differs from previous approaches by combining a continuous phase range of the unit cells with a working frequency in the K-band.
Keywords: Transmitarray; Reconfigurable Antenna; Beam Steering

A Multimode Receiver Front-End for Software Defined Radio - Kruth, A.; Simon, Martin; Dufrene, Krzysztof; Weigel, Robert; Boos, Zdravko; Heinen, Stefan (European Conference on Wireless Technology (ECWT), 2006)
A flexible multimode receiver architecture for software defined radio systems with focus on GSM, WCDMA and CDMA systems has been designed in a 120 nm CMOS technology. The receiver consists of a wideband coilless common gate LNA2 with gain switches and a high linearity down-converter with current interface between mixer and baseband-filter. The LO signal of a 8 GHz VCO and divider with ratio 4 respectively 8 covers the whole receiver frequency range. The receiver consumes 32 mA at 1.5 V supply voltage.
elib2cris::1512001600,kruth2006
Keywords: broadband amplifiers; demodulators; gain; measurements; mixer noise; mobile communications; receivers

A multi-PMT optical module for the IceCube upgrade - Dorn, Christian; Kossatz, M.; Kretzschmann, A.; Ortjohann, H. W.; Reubelt, Jonas; Sulanke, K. H.; Weigel, Robert; Classen, Lew; Kappes, Alexander; Karg, Timo (Proceedings of Science, 2019)
Following the first observation of an astrophysical high-energy neutrino flux with the IceCube Neutrino Observatory in 2013 and the identification of a first cosmic high-energy neutrino source in 2017, the detector will be upgraded with about 700 new advanced optical sensors. This will expand IceCube's capabilities both at low and high neutrino energies. A large fraction of the upgrade modules will be multi-PMT Digital Optical Modules, mDOMs, each featuring 24 three-inch class photomultiplier tubes (PMTs) pointing uniformly in all directions, thereby providing an almost homogeneous angular coverage. The signal from each PMT is digitized individually, providing directional information for the incident photons. Together, the 24 PMTs provide an effective photosensitive area more than twice than that of the current IceCube optical module. The main mDOM design challenges arise from the constraints on the module size and power needed for the 24-channel high-voltage and readout systems. This contribution presents an mDOM design that meets these challenges and discusses the sensitivities expected from these modules.
CRIS-Team Scopus Importer:2021-04-20

A Multi-Purpose Simulation Tool for Evaluation and Analysis of Variability Impact on Low Power Memory Organizations - Grabner, Thomas; Miranda, Miguel; Papanikolaou, Antonis; Huemer, Mario (Austriachip, 2006)
elib2cris::1512001600,grabner2006

A Multistandard HF/ UHF-RFID-Tag With Integrated Sensor Interface and Localization Capability - Ußmüller, Thomas; Brenk, Daniel; Essel, Jochen; Heidrich, Jürgen; Fischer, Georg; Weigel, Robert (6th Annual IEEE International Conference on RFID, 2012)
elib2cris::1512001600,ussmueller2012

An 802.11a/b/g RF Transceiver in an SoC - Simon, Martin; Laaser, P.; Filimon, V.; Geltinger, H.; Friedrich, D.; Raman, Y.; Weigel, Robert (IEEE International Solid-State Circuits Conference, 2007. ISSCC 2007, 2007)
The RF transceiver of a 0.13mum CMOS WLAN 802.11 a/b/g SoC for cellular applications comprising MAC, PHY, and analog front-end is presented. The transceiver with direct-conversion architecture and broadband 12GHz VCO draws 87/104mA in TX and 69/80mA in RX mode for the 2.4/5.0GHz band. The TX with control loop achieves -32dB EVM at -2dBm output power with 1.5V supply.
elib2cris::1512001600,simon2007

An 8-32GHz Frequency Synthesizer based on a Wideband VCO Array with Bandwidth Extension Stage - Nehring, Johannes; Fischer, Georg; Weigel, Robert; Kissinger, Dietmar (German Microwave Conference (Gemic), 2014)
This paper proposes a wideband signal source covering a bandwidth of two octaves from 8 GHz to 32 GHz. The system is based on an array of three wideband voltage controlled oscillators (VCOs) for octave wide frequency syn- thesis and a post-synthesis stage which extends the bandwidth by another octave. The circuits were fabricated in a 0.35 μm SiGe bipolar technology with an ft/fmax= 170/250GHz. The VCO tuning ranges are 28.9 %, 26.2 % and 24.7 % respectively. The average output power was measured to be −3.5 dBm. The single-sideband phase noise at 1 MHz offset has an average value of −100 dBc/Hz over the entire bandwidth of two octaves. The system blocks VCO array, bandwidth extension and output buffer consume a power of 175 mW, 277 mW and 150 mW.
elib2cris::1512001600,nehring2014a

An 8-32 GHz frequency synthesizer based on a wideband VCO array with bandwidth extension stage - Nehring, Johannes; Fischer, Georg; Weigel, Robert; Kissinger, Dietmar (8th German Microwave Conference, GeMiC 2014, 2019)
This paper proposes a wideband signal source covering a bandwidth of two octaves from 8 GHz to 32 GHz. The system is based on an array of three wideband voltage controlled oscillators (VCOs) for octave wide frequency synthesis and a post-synthesis stage which extends the bandwidth by another octave. The circuits were fabricated in a 0.35 µm SiGe bipolar technology with an ft/fmax = 170/250 GHz. The VCO tuning ranges are 28.9 %, 26.2 % and 24.7 % respectively. The average output power was measured to be −3.5 dBm. The single-sideband phase noise at 1 MHz offset has an average value of −100 dBc/Hz over the entire bandwidth of two octaves. The system blocks VCO array, bandwidth extension and output buffer consume a power of 175 mW, 277 mW and 150 mW.
CRIS-Team Scopus Importer:2021-04-20
Keywords: VCO; Voltage controlled oscillator; Wideband frequency synthesis

An Accurate Free Space Method for Material Characterization in W-Band Using Material Samples with Two Different Thicknesses - Lau, Isabella; Frank, Martin; Shi, Kilin; Lurz, Fabian; Talai, Armin; Weigel, Robert; Kölpin, Alexander (European Microwave Conference (EuMC), 2018)
This paper presents an accurate free space method for material characterization eliminating the problem of the required precise orientation between the material and the antennas and expanding the unambiguous range for electrical thick samples. It includes theoretical considerations and measurement results of four different materials. Overall, a maximum measurement uncertainty of 0.0153 for the relative permittivity and 0.001 for the loss tangent in the W-band can be achieved. Depending on the variation of the material’s thickness, the implemented setup changes lead to an reduction of the measurement uncertainty of 8 to 58%.<br
Keywords: permittivity; dielectric materials; microwave measurement; materials nondestructive testing

An acoustic emmission sensor system for thin layer crack detection - Unterreitmeier, Marianne; Nagler, Oliver; Pfitzner, Lothar; Weigel, Robert; Holmer, Rainer (29th European Symposium on Reliability of Electron Devices, Failure Physics and Analysis, 2018)

An Active Constraint Method for Distributed Routing, and Power Control in Wireless Networks - Ferizi, Alban; Dekorsy, Armin; Fliege, Jörg; Popova, Larissa; Koch, Wolfgang; Söllner, Michael (EURASIP Journal on Wireless Communications and Networking, 2009)
Efficiently transmitting data in wireless networks requires joint optimization of routing, scheduling, and power control. As opposed to the universal dual decomposition we present a method that solves this optimization problem by fully exploiting our knowledge of active constraints. The method still maintains main requirements such as optimality, distributed implementation, multiple path routing and per-hop error performance. To reduce the complexity of the whole problem, we separate scheduling from routing and power control, including it instead in the constraint set of the joint optimization problem. Apart from the mathematical framework we introduce a routing and power control decomposition algorithm that uses the active constraint method, and we give further details on its distributed application. For verification, we apply the distributed RPCD algorithm to examples of wireless mesh backhaul networks with fixed nodes. Impressive convergence results indicate that the distributed RPCD algorithm calculates the optimum solution in one decomposition step only.
elib2cris::1512001600,ferizi2009

An Additive Manufactured K-Band Waveguide Coupler and K-Band Antennas in SLM-Technology - Beck, Christopher; Gabsteiger, Jasmin; Scheitler, Christian Josef; Dietz, Marco; Hagelauer, Amelie Marietta; Weigel, Robert (2020)

An advanced continous multi-level EMC simulation process for automotive applications - Weigel, Robert; Frank, Florian (Embedded World Conference, 2009)
elib2cris::1512001600,weigel2009

An Advanced Millimeter-Wave FMCW-Radar System Simulation Environment for the Automotive Sector - Dudek, Manuel; Kissinger, Dietmar; Weigel, Robert; Fischer, Georg (12. GMM/ITG-Fachtagung ANALOG, 2011)
In this paper a millimeter-wave radar system simulation environment for frequency-modulated continuous-wave radar using a 3D ray tracing channel simulator is presented. Therefore we use Agilent’s RF design environment ADS® for system simulation and calculate the channel impulse response based on the data received from a 3D ray tracer in a Matlab® co-simulation. To reduce computing time the whole signal flow is processed in a complex baseband representation and scattering center models are used as substitute for complex polygon targets as further improvement. Nevertheless all effects occurring at harmonic bands due to nonlinearities in the transmitter and receiver circuits are well reflected in the simulation. A typical road scenario is simulated and the results show the capabilities of the simulation approach in terms of speed and accuracy.
elib2cris::1512001600,dudek2011e

An AGC Proposal with Frame and Carrier Synchronization for Burst Transmission Systems - Reinhardt, Steffen; Trommer, I.; Huemer, Mario (European Wireless Conference, 2006)
This paper provides an automatic gain control (AGC) algorithm applicable in high speed burst communication systems. Since under multipath propagation a common AGC can severely degrade the performance of the frame synchronization algorithms used in packet transmission systems, a new interface is particularly designed to perform automatic gain control in conjunction with the applied timing and coarse frequency synchronization. We simulated our AGC interface in a Single Carrier (SC) system with Frequency Domain Equalization (FDE) in the presence of noise and multipath fading, but the techniques are also applicable to multi-carrier systems as orthogonal frequency division multiplexing (OFDM). Simulation results let conclude that the applied synchronization algorithms in combination with our AGC interface do not need a preamble as long as the short preamble specified in IEEE802.11g to yield an optimal system performance.
elib2cris::1512001600,reinhardt2006

Analog Compensation of AM-AM and AM-PM effects for HighEfficiency Stacked-FET Power Amplifiers in 65-nm Standard CMOS - Zohny, Amr; Leuschner, Stephan; Rascher, Jochen; Pinarello, Sandro; Ußmüller, Thomas; Müller, Jan-Erik; Fischer, Georg; Weigel, Robert (European Microwave Integrated Circuits Conference (EuMIC), 2013)
Simultaneously achieving high linearity and high power-added efficiency (PAE) is essential for power amplifiers (PA) operating with modern communication signals. The challenge is exacerbated by the low breakdown voltages of standard CMOS realizations. This work presents a low-complexity programmable analog scheme to compensate the strong AM-AM and AM-PM nonlinearities of the high-ruggedness stacked-cascode topology while maintaining high PAE. The proposed solution utilizes standard NMOS devices to achieve peak PAE of 60% at the 900 MHz band from a 3V supply. The compensation scheme manages to improve the output 1-dB compression point by up to 2 dB and keep the AM-PM variation within 5 degrees. The proposed method improves the linear output power (@ ACPR= -40 dBc) for a Class-AB power amplifier by up to 1.5 dB without compromising PAE or saturated output power
elib2cris::1512001600,zohny2013a
Keywords: Power amplifier; Stacked FET; Stacked cascode; CMOS; linearization; ruggedness

Analog Computation Methods with the help of analog and pseudo-digital Carry Signals - Söll, Christopher; Shi, Lan; Bänisch, Andreas; Röber, Jürgen; Ußmüller, Thomas; Weigel, Robert (IEEE European conference on circuit theory and design (ECCTD), 2015)
This work describes new methods of handling exceedings of the supply range in analog computation stages. These are handled as pseudo-digital and analog carry signals and used to regulate the gain of the stage where they occur as well as all computation stages that follow. A complete example for such an analog computation is simulated and presented and critical parts of the architectures are addressed. In addition, more sophisticated extensions are proposed and the ”right” way of carry handling is explained for a specific algorithm, together with a discussion of the advantages of different methods for each application.
elib2cris::1512001600,soell2015a
Keywords: analog computation; analog carry; pseudo-digital carry; pre-processing; GRK-1773

Analog Non-Linear Transformation-Based Tone Mapping for Image Enhancement in C-arm CT - Shi, Lan; Berger, Martin; Bier, Bastian; Söll, Christopher; Röber, Jürgen; Fahrig, Rebecca; Eskofier, Björn; Maier, Andreas; Maier, Jennifer (IEEE Medical Imaging Conference (MIC), 2016)
Flat-Panel C-arm Computed Tomography (CT) suffers from pixel saturation due to the detector’s limited dynamic range. We describe a novel approach to analog, non-linear tone mapping (TM) for preventing detector saturation. An analog TM operator (TMO) applies a non-linear transformation in a CMOS sensor and its inverse TMO based on 14-bit digital raw data. This is done in order to prevent overexposure and to enhance image quality to 32 bits. The method was applied to the cases of low-contrast head imaging and to that of imaging both knees. Cone-beam projection data with and without overexposure was simulated for a 200° short-scan of the knees and a 360° full-scan of a Forbild head phantom. The results show an increased correlation coefficient of 0.99 compared to 0.96 for overexposed knee data and a higher low-contrast visibility (CC=0.99) compared to linear quantization (CC=0.97
elib2cris::1512001600,shi2016a
Keywords: GRK-1773

Analyse der Sende-Empfangsverkopplung in einem homodynen, bistatischen 77 GHz-Automobilradar - Mittelstraß, Delf (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2013)

Analyse leitungsgeführter EMV-Störsignale an der Schnittestelle Integrierter Schaltkreis/Komponente - Frick, Marco (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2012)

Analyse und Modellierung der Funkausbreitung in Passagierkabinen von Großraumflugzeugen - Bachhuber, Martin (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2011)

Analyse und Verhaltensmodellierung des HF-Frontends von passiven CMOS-Transpondern für UHF-RFID-Anwendungen - Seemann, Kay (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2007)

Analysis and Cancellation Methods of Second Order Intermodulation Distortion in RFIC Downconversion Mixers - Dufrene, Krzysztof (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2007)
elib2cris::1512001600,dufrene2007a

Analysis and Compensation of Relative Humidity and Ice Formation Effects for Radar-Based SHM Systems Embedded in Wind Turbine Blades - Simon, Jonas; Moll, Jochen; Krozer, Viktor; Kurin, Thomas; Lurz, Fabian; Bagemiel, Oliver; Krause, Stefan (EUROPEAN WORKSHOP ON STRUCTURAL HEALTH MONITORING (EWSHM 2022), VOL 3, 2023)
CRIS-Team WoS Importer:2022-11-11

Analysis and Design of Monolithic Integrated SiGe Mixer Circuits for 77 GHz Automotive Radar - Hartmann, Marcus (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2008)

Analysis of a built-in test architecture for direct-conversion SiGe millimeter-wave receiver frontends - Kissinger, Dietmar; Agethen, Roman; Weigel, Robert (IEEE Instrumentation and Measurement Technology Conference, 2010)
elib2cris::1512001600,kissinger2010c

Analysis of a Microstrip Patch Array Fed Cylindric Lens Antenna for 77GHz Automotive Radar - Wenig, Peter; Weigel, Robert (IEEE Antennas and Propagation Symposium (ISAP), 2008)
elib2cris::1512001600,wenig2008b

Analysis of a Physically-Embedded Radar Sensor System - Kurin, Thomas; Issakov, Vadim; Erhardt, Stefan; Weigel, Robert; Lurz, Fabian (2021 18TH EUROPEAN RADAR CONFERENCE (EURAD), 2021)
CRIS-Team WoS Importer:2022-08-26

Analysis of Combined Frequency Drift and Offset for Galileo/GPS Single Shot Receiver Architectures - Ehm, Henning; Winter, Sebastian; Weigel, Robert (International Symposium on Signals, Systems, and Electronics (ISSSE 2007), 2007)
This paper analyzes the combined effect of a residual frequency offset and drift after down-conversion for single shot receiver architectures as they are currently utilized in mobile terminals for GPS reception. The change in the receiver detection probability due to this effect is calculated, as well as the associated connected sensitivity-loss. The obtained results are given for the GPS C/A code and open Galileo signal, both in the L1 band.
elib2cris::1512001600,ehm2007

Analysis of Decompressed Audio - 'The Inverse Decoder' - Herre, Jürgen; Schug, Michael (19´09th AES Convention, 2000)
Vorträge und Veröffentlichungen auf Konferenzen_Gehörangepasste Datenreduktion

Analysis of General Multichannel Waveguides - Jungwirth, Mario; Pöcksteiner, Norbert; Kovacs, Günter; Weigel, Robert (IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2002)
Using the planar waveguide concept in surface acoustic wave (SAW) technology is often advantageous when the modeling of transversely distributed phenomena is indispensable for an accurate design of SAWdevices. This is especially true when complex multi-track structures such as transversely coupled resonator filters (TCRFs) are under consideration where, e.g., transverse velocity and stiffness profiles have to be incorporated in the device simulation. The interdigital transducers (IDTs) and the reflector gratings composing those devices behave as planar waveguides, supporting, in principle, all kinds of modes such as bound, semi-bound, and radiation modes. Therefore, to model these SAW propagation effects, we subdivide the SAW structures in transverse direction into several parallel waveguiding channels (N regions), and take, as the wave-describing quantity, a two-dimensional scalar potential function. By doing so, we obtain a complete set of orthonormal modes into which an arbitrary transverse excitation function can be expanded to study its propagation. The general mode spectrum includes a discrete spectrum of bound modes and continuous spectra of semi-bound and radiation modes. We calculate all types of modes by making use of the stack matrix technique. The present work, which arose from the requirement of creating an efficient mathematical tool for the simulation of TCRFs, provides the complete analysis of general SAW multi-channel structures.
elib2cris::1512001600,jungwirth2002a
Keywords: Multichannel; Waveguide

Analysis of General Planar Waveguides with N Segments - Pöcksteiner, Norbert; Jungwirth, Mario; Kovacs, Günter; Weigel, Robert (IEEE International Ultrasonics Symposium, 2000)
elib2cris::1512001600,poecksteiner2000

Analysis of Key Modules in an Analog Front-End for Scanning Receiver Systems - Mzyk, Raphael; Dehm-Andone, Gunther; Langmann, Frank; Fischer, Georg; Weigel, Robert; Kölpin, Alexander (IEEE International Conference on Microwaves, Radar & Wireless Communications, 2012)
In this paper, a cost-effective approach on receiver systems for frequency scanning and direction finding applications is presented. A hybrid approach on analog front-end topology is introduced, that combines direct sampling and double superheterodyne architecture. Key modules like a reconfigurable filter, reference clock distribution units, and low noise PLL (phaselocked loop) are highlighted and the trade-off between cost effectiveness and performance is investigated. The performance of those modules is presented by measurement results.
elib2cris::1512001600,mzyk2012a
Keywords: Scanning receiver; surveillance; clock distribution; frequency synthesis; reconfigurable filter

Analysis of Low Profile Ferrite Material Based Planar Shell Core Inductor - Umar, Zeeshan; Engelsberger, Franz Xaver; Wojnowski, Maciej; Hagelauer, Amelie Marietta; Weigel, Robert (2018 IEEE 20TH ELECTRONICS PACKAGING TECHNOLOGY CONFERENCE (EPTC), 2018)
CRIS-Team WoS Importer:2019-04-12

Analysis of onboard channel measurements for train communication scenarios in the context towards 6G enabling technologies - Lichtblau, Johann; Elkholy, Kariem; Koelpin, Alexander (2022 52nd European Microwave Conference, EuMC 2022, 2022)
This paper examines the channel characterization of onboard train communication scenarios in the context of the technology shift from 5G to 6G. It identifies the research gaps that still exist today in train onboard communications and consequently what needs to be addressed for future generation technology. In addition, the special circumstances in the train sector will be evaluated on the basis of channel measurements in the high-speed sector at 3.6 GHz., previous results will be reviewed., and research recommendations will be made. For this purpose., four scenarios are discussed for the train domain., enabling the safeguarding of developments., especially in the field of safety-critical rail infrastructures.
CRIS-Team Scopus Importer:2022-12-02
Keywords: railway communication; wireless communication

Analysis of power distribution systems on PCB level via reduced PEEC-modeling - Steinmair, Gernot; Weigel, Robert (International Conference on Microwaves, Radar and Wireless Communications, 2004)
PowerGND-system simulation together with decoupling analysis on PCB level is mandatory in order to reach shorter development times of electric and electronic components and to prevent malfunctioning of future products. The partial elements equivalent circuit (PEEC) method is applied for modeling general PCB power-ground layouts. In order to overcome the continuously increasing complexity of the resulting models, a combination of moment-matching via Krylov subspace projection and SVD-based Truncated Balanced Realization is applied for reducing the order of the PEEC models. The method of modeling and model reduction is demonstrated by means of a practical example.
elib2cris::1512001600,steinmair2004

Analysis of SAW Interdigital Transducers as Waveguides with N Acoustic Regions - Jungwirth, Mario; Pöcksteiner, Norbert; Weigel, Robert (IEEE International Ultrasonics Symposium, 2001)
Using the planar waveguide concept in surface acoustic wave (SAW) technology is often advantageous when the modeling of transversely distributed phenomena is indispensable for an accurate design of SAW devices. This is especially true when complex multi-track structures such as transversely coupled resonator filters (TCRF's) are under consideration where, e.g., transverse velocity and stiffness profiles have to be incorporated in the device simulation. The interdigital transducers (IDT's) and the reflector gratings composing those devices behave as planar waveguides supporting in principle all kinds of modes such as bound, semi-bound and radiation modes. Therefore, to model these SAW propagation effects, we subdivide the SAW structures in transverse direction into several parallel waveguiding channels (N regions), and take, as the wave-describing quantity, a two-dimensional scalar potential function. By doing so, we obtain a complete set of orthonormal modes into which an arbitrary transverse excitation function can be expanded in order to study its propagation. The general mode spectrum includes a discrete spectrum of bound modes and continuous spectra of semi-bound and radiation modes, respectively. We calculate all types of modes by making use of the stack matrix technique. The present work provides some results in the simulation of waveguides with N acoustic regions using the complete analysis of general SAW multi-channel structures presented previously
elib2cris::1512001600,jungwirth2001
Keywords: SAW; Interdigital Transducers

Analysis of Substrate Coupling in Integrated Circuits Using Boundary Element Method and Monopole Expansion - Weigel, Robert; Brandtner, Thomas (East-West Workshop on Advanced Techniques in Electromagnetics, 2004)
elib2cris::1512001600,weigel2004

Analysis of Surface Acoustic Wave Propagation in Layered Media - Weigel, Robert; Roesler, Ulrike; Meier, Hans; Russer, Peter (Proc. progress in Electromagnetics Research Symposium, 1994)
elib2cris::1512001600,weigel1994b

Analysis of System Parameters of a Six-Port Communications Receiver with Analog I/Q Regeneration - Winter, Sebastian; Ehm, Henning; Kölpin, Alexander; Weigel, Robert (International Symposium on Signals, Systems and Electronics, 2007. ISSSE '07, 2007)
In this paper system level parameters for the compression behavior as well as second and third order distortions of a six-port communications receiver with analog I/Q regeneration are determined by system simulations. The parameter values are qualified for a range of local oscillator (LO) signal powers. A recommendation for a well-suited LO signal power is derived from the resulting parameter plot. The recommended LO signal power is supported by investigation of the receiver's conversion efficiency. The results are also valid for other ways of I/Q regeneration based on passive mixing.
elib2cris::1512001600,winter2007

Analysis of the interaction of surface acoustic waves with charge carriers in layered structures - Weigel, Robert; Roesler, Ulrike; Meier, Hans; Russer, Peter (IEEE Ultrasonics Symposium, 1994)
We have computed the propagation behavior of surface acoustic waves (SAW's) under a non-piezoelectric, conducting layer on a semi-infinite piezoelectric substrate. Due to the finite conductivity of the film which is deposited on the substrate surface the interaction of the SAW with the charge carriers in this layer involves changes in both attenuation and dispersion. In our analysis, mass loading and stress loading are taken exactly into account. We also include the space charge density distribution in the film by using and comparing four different space charge models. As an example, we present the phase velocity and the attenuation coefficient of the fundamental SAW mode propagating on a 128rotYX LiNbO3 substrate coated with a thin layer of amorphous silicon (a:Si) as a function of the silicon conductivity and the film thickness. It is found that an appropriately dimensioned semiconducting film may be used as an efficient absorbing material in SAW devices for consumer and commercial applications
elib2cris::1512001600,weigel1994d

Analysis of the Movement of ICD Leads During Cardiac Contraction as Determinant of Intracardiac Impedance - Kirchner, Jens; Fischer, Georg; Arnold, Martin (2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2018)
Intracardiac impedance (ICI) has been proposed as an indicator of cardiac status in heart failure patients. We introduce a biophysical model of the measurement setup and apply it to the movement of ICD leads reconstructed from clinical-routine X-ray recordings in a study population of 12 patients. Tilting of the right ventricular lead is found to be a major determinant of ICI changes during cardiac contraction with a mean contribution of 42+-23%. The relative position between right and left ventricular lead is the second major contributor (40+-22%). However, the contributions of the components of movement strongly differ between the patients. The proposed method provides means for a better interpretation of ICI measurements and for an improvement of its performance for monitoring heart failure statu

Analysis of the Settling Behavior of an External Reference Voltage Source for a 16 Bit and 200 MS/s Pipeline Analog-to-Digital Converter - Löhr, Robert; Bender, Leon; Röber, Jürgen; Ohnhäuser, Frank; Weigel, Robert (24th IEEE International Conference on Electronics, Circuits and Systems (ICECS), 2017)
High-Performance Analog to Digital Converter (ADC) have high requirements concerning the reference voltage source. In a small period of time the reference voltage has to settle with a high accuracy. Otherwise the linearity of the ADC degrades. In this paper the settling of an external reference voltage source is examined. Therefore optimization techniques for the signal path of the reference voltage are presented. This includes methods for reducing the external parasitic inductanceas well as design techniques for an enhanced settling curve. Under typical conditions, the achieved reference voltage source settles with an accuracy of 15 uV in less than halve a clock cycle for a 200 MS/s and 16 bits Pipeline ADC.
Keywords: reference voltage; settling; Pipeline ADC; external parasitic inductance; attenuation

Analytical Equivalent Circuit Extraction Procedure for Broadband Scalable Modeling of Three-Port Center-Tapped Symmetric On-Chip Inductors - Issakov, Vadim; Kehl-Waas, Sebastian; Breun, Sascha (IEEE Transactions on Circuits and Systems I-Regular Papers, 2019)
This paper presents a new, almost fully analytical methodology for component value extraction of a double-π equivalent circuit model for three-port on-chip inductors from a given S-parameter dataset. The compact model provides an accurate fit over a wide frequency range from dc to beyond the self-resonance frequency (SRF) to a tabular input S-parameter model describing a symmetric center-tapped on-chip inductor. The input dataset may be obtained from a measurement or from an electromagnetic field solver simulation. Using a passive broadband equivalent circuit instead of the original S-parameters' description is advantageous for circuit design, as it facilitates the convergence of transient simulations. The proposed approach carefully considers center-tap parasitics. Hence, the obtained equivalent circuit model fits the input inductor characteristics accurately not only for differential excitation but also in the common-mode and single-ended operation. Due to the fact that the proposed extraction approach is based on physical assumptions and analytical circuit decomposition, the obtained component values are physically meaningful and relate to geometry. Thus, this approach is suitable for the generation of scalable compact models, which can be used to speed-up inductor optimization during the RF circuit design. The proposed methodology has been verified on a three-port inductor realized in a 28-nm CMOS technology and measured up to 60 GHz. The extracted equivalent circuit model exhibits an accurate fit to the measured data over the entire frequency range in all operation modes. Finally, field-solver models are used to verify the scalability.<br
Keywords: circuit optimisation; CMOS integrated circuits; equivalent circuits; inductors; integrated circuit modelling; multiport networks; network analysis; radiofrequency integrated circuits; S-parameters; input inductor characteristics; analytical circuit decomposition; analytical equivalent circuit extraction procedure; component value extraction; double-π equivalent circuit model; self-resonance frequency; symmetric center-tapped on-chip inductor; passive broadband equivalent circuit; center-tap parasitics; Broadband Scalable Modeling; three-port center-tapped symmetric on-chip inductors; S-parameter dataset; electromagnetic field solver simulation; single-ended operation; common-mode operation; transient simulations; CMOS technology; Integrated circuit modeling; Inductors; Equivalent circuits; Analytical models; Scattering parameters; Geometry; Numerical models; Equivalent circuit; on-chip inductor; center-tap

Analytic Quantization Modeling of OFDM Signals Using Normal Gaussian Distribution - Ehm, Henning; Winter, Sebastian; Weigel, Robert (Asia-Pacific Microwave Conference, 2006)
This paper presents a rigorous analytic approach for the quantization of OFDM signals. The signal-to-noise ratio at the ADC output is derived as a function of the input signal's standard deviation and the ADC input range. Furthermore, the maximum signal-to-noise ratio is calculated for various ADC resolutions. The analytic results are verified by simulations applying an OFDM WLAN signal as well as normal distributed white Gaussian noise.
elib2cris::1512001600,ehm2006a
Keywords: Quantization; OFDM; clipping noise; quantization noise; digital communication systems

Analyzing the Target recognition Capability of an Ultra-Wideband Radar System Using Time Frequency Algorithms - Buchegger, Thomas; Oßberger, Gerald; Schimbäck, Erwin; Stelzer, Andreas; Weigel, Robert (Proceedings Ultra-Wideband, Short-Pulse Electromagnetics Conference, 2004)
elib2cris::1512001600,buchegger2004a

An analog baseband chain for a UMTS zero-IF receiver in a 75 GHz SiGe BiCMOS technology - Schelmbauer, Werner; Pretl, Harald; Maurer, Linus; Adler, Bernd; Weigel, Robert; Hagelauer, Richard; Fenk, Josef (Radio Frequency Integrated Circuits (RFIC) Symposium, 2002)
A zero-IF receiver for UMTS realized by using an advanced 0.35 μm SiGe BiCMOS process with 75 GHz transit frequency is presented. The focal point is the analog baseband chain consisting of a low-noise buffer (LNB), a fully integrated channel selection filter, programmable gain amplifiers (PGA) and circuits to reduce the effects of DC-offsets. The whole chain is able to provide a voltage gain from -14 dB up to 50 dB in 1 dB steps and 43 dB adjacent channel selectivity. The total receiver current consumption for a supply voltage of 2.7 V is less than 45 mA, whereby the baseband chain consumes 15 mA.
elib2cris::1512001600,schelmbauer2002