Initial Calibration Procedure of a Six-Port Receiver System for Complex Data Reception - Lindner, Stefan; Barbon, Francesco; Vinci, Gabor; Weigel, Robert; Kölpin, Alexander (42nd European Microwave Conference (EuMC), 2012)

In-Line Material Characterization Sensors Operating at 10 GHz and 77 GHz - Frank, Martin; Talai, Armin; Weigel, Robert; Kölpin, Alexander (Asia Pacific Microwave Conference (APMC) 2017, 2017)
This paper describes the design of two sensors for the in-line material characterization of bulk and metallized dielectrics around 10,GHz and 77,GHz in order to determine the relative permittivity of RF substrates. The sensors are based on a resonant grounded coplanar waveguide structure and can be applied on top of a material under test. The shift in the resonance frequency between loaded and unloaded resonator is evaluated by 3D full wave simulations in order to determine the relative permittivity. The basic sensor structure is improved for the in-line characterization of printed circuit boards by a clearance of the resonator area and the filling of the air gaps. Measurements with different MUTs were performed with both sensors followed by the evaluation of the relative permittivity. The results are in good agreement with the expected permittivity values and show high reproducibilit
Keywords: Material Characterization; Relative Permittivity; Grounded Coplanar Waveguide

Innovative Differential Magnetic Localization Method for Capsule Endoscopy to Prevent Interference Caused by the Geomagnetic Field - Zeising, Samuel; Anzai, Daisuke; Thalmayer, Angelika; Fischer, Georg; Kirchner, Jens (Advances in Radio Science : Kleinheubacher Berichte, 2021)

Innovative Hybrid Halbach Array for Steering Magnetic Nanoparticles Through a Bifurcation - Thalmayer, Angelika; Fischer, Georg (Current Directions in Biomedical Engineering, 2023)

Innovative Key Generation Approach to Encrypt Wireless Communication in Personal Area Networks - Bichler, Daniel; Stromberg, Guido; Huemer, Mario (Global Telecommunications Conference, 2007. GLOBECOM '07. IEEE, 2007)
In this paper we present a signal processing methodology for sharing symmetric keys in personal area networks. Symmetric encryption and decryption are commonly used because of limitations in computing power and energy consumption. However, key sharing still imposes challenges regarding usability, computational complexity of algebraic key exchange algorithms, and security. Our approach is that keys are generated locally on devices by shaking them, and that the keys are equal if and only if the devices are shaken together. Based on practical assessments, we show that the key generation algorithm is able to generate keys from acceleration data with an average entropy of 13bit/key in 70% of the cases.
elib2cris::1512001600,bichler2007
Keywords: algebraic key exchange algorithm; computational complexity; energy consumption; key generation algorithm; personal area networks; power consumption; signal processing; symmetric decryption; symmetric encryption; wireless communication

Innovative LED Beleuchtung im Historischen Stadtkern Potenziale und Akzeptanz eines neuen Lichtkonzepts - Werner, Daniel; Gabel, Kristin; Schwenzfeier-Hellkamp, Eva (8. LiTG-Tagung Stadt- und Außenbeleuchtung, 2013)

In-Situ EMF Measurements of Rooftop Attenuation for Assessment of the Compliance Boundary of Cellular Base Stations - Reese, Roland; Michler, Fabian; Scheiner, Benedict; Radermacher, Eva (IEEE Access, 2022)

In-Situ-Linearization for Instantaneous Frequency Measurement Systems - Scheiner, Benedict; Lurz, Fabian; Michler, Fabian; Weigel, Robert; Kölpin, Alexander (European Microwave Week 2019, 2019)

In-Situ Testing of a Multi-Band Software-Defined Radio Platform in a Mixed-Field Irradiation Environment - Budroweit, Jan; Müller, Steffen; Jaksch, Matthis; Garcia Alía, Rubén; Coronetti, Andrea; Kölpin, Alexander (Aerospace, 2019)
This paper presents an in-situ test concept for a multi-band software-defined radio (SDR) platform in a mixed-field radiation environment. Special focus is given to the complex automated test setup with respect to the requirements of the irradiation facility. Additionally, selected test results of a system-level evaluation are presented and discussed. For the verification of the mixed-field radiation environment, the software-defined radio (SDR) was also tested under proton irradiation. The cross-sections for the observed single event eects are compared and show similar results.<br
Keywords: in-situ testing; automated test setup; mixed-field irradiation; total dose effects; single event effects; software-defined radio

In-Situ Time-Frequency Analysis of the 77 GHz Bands using a Commercial Chirp-Sequence Automotive FMCW Radar Sensor - Gardill, Markus; Schwendner, Johannes; Fuchs, Jonas (2019 IEEE MTT-S International Microwave Symposium (IMS), 2019)
A commercial chirp-sequence automotive radar sensor is reconfigured to allow for time-frequency analysis of the 77GHz automotive radar bands. Compared to highend measurement equipment such as real-time spectrum analyzers, due to its low cost and compact size the proposed approach allows for in-situ interception and time-frequency analysis of traffic scenarios, e.g. by mounting the sensor in a test vehicle exactly at the positions where the radar sensors would be mounted. The theory behind the modification is discussed and compared with measurements. Time-frequency spectra of a rural road driving scenario obtained with the proposed system are shown to illustrate the practical relevance and usefulness of the approac
Keywords: radar; automotive; FMCW; chirp-sequence; time-frequency analysis

Insole Gait Acquisition System Based on Wearable Sensors - Gogoi, Niharika; Fischer, Georg; Kirchner, Jens; Yu, Zixuan; Qin, Yichun (Engineering Proceedings, 2021)
Human gait analysis is a growing field of research interest in medical treatment, diagnosis, sports training, and structural health monitoring. It is the study of graphical representation of human motion through observation method (video or image-based) in a clinical setup or placing sensor method at different parts of the body, to understand the condition of human muscles, mechanics, and fitness. Out of the two methods, the role of wearable sensors in such clinical applications is crucial because of their low cost, simple implementation, and time to time monitoring. In our study, we propose an insole design for wearable sensors based on lead zirconate titanate piezoelectric discs (PZT) and inertial measurement unit (IMU) BMI270 to acquire the human gait. A PZT and an IMU aligned on the same axis are placed in a metallic structure. Such structures are placed at three points of a shoe sole: toe, metatarsal, and heel. The human gait obtained from this insole layout is significantly affected by plantar pressure distribution and alignment of the feet. The PZT sensors give an insight into the pressure map under the feet in the form of voltage. The accelerometer in the IMU gives the change of position of the feet to examine the gait analysis. The gyroscope in IMU is used for the understanding of the motion and posture of feet by measuring its angular rate. The acquired data from these sensors shows that each individual has a different gait pattern at the three points in the sole. It also shows intra-individual variations where the gait of the same person varies in daily situations.<br

Instantaneous frequency measurement based on low-cost Six-Port technology - Lindner, Stefan; Vinci, Gabor; Barbon, Francesco; Linz, Sarah; Mann, Sebastian; Weigel, Robert; Kölpin, Alexander (European Microwave Conference, 2013)
This paper describes a new approach for absolute, high accuracy and fast responding millimeter wave frequency measurement. The shown system is based on the reduction of the frequency detection to a phase measurement with a delay line and a subsequent determination of the phase. By using a Six-Port structure, this phase can be evaluated very precisely, leading to a accurate frequency detection. Another remarkable point is the fast system response, because there is neither time consuming transformation to frequency domain nor long integration time required.
elib2cris::1512001600,lindner2013a
Keywords: delay lines; frequency measurement; Detectors; millimeter wave measurement; phase measurement

Instantaneous Heartbeat Detection using a Cross-Correlation based Template Matching for Continuous Wave Radar Systems - Will, Christoph; Shi, Kilin; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2016)
Instantaneous heartbeat detection is necessary for an optimal patient monitoring in healthcare centers. Whereas electrocardiogram (ECG) and ballistocardiogram (BCG), for instance, are established methods for real time monitoring nowadays, contact-free systems are appreciated. Herewith, a 24 GHz continuous wave (CW) radar system with an intelligent signal processing is presented. Common heartbeat detection algorithms use the fast Fourier transform (FFT), and therefore require an adequate observation time window and rather detect an averaged heart rate. The proposed algorithm in contrast accomplishes the detection of single heart beats directly in the time domain with an insignificant delay. The core of that algorithm is a template matching using the cross-correlation method. In this paper, after describing the radar system with the novel signal processing, the presented system is compared to a commercial ECG produc
elib2cris::1512001600,will2016
Keywords: Radar interferometry; Biomedical signal processing; Template matching

Integrated adaptive LO leakage cancellation for W-CDMA direct upconversion transmitters - Lanschützer, Christian; Springer, Andreas; Maurer, Linus; Boos, Zdravko; Weigel, Robert (IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, 2003, 2003)
A method for on-chip implementation is presented to compensate both local oscillator leakage due to finite LO to RF port isolation and input DC offset. It uses an RF power detector and a digital control loop and is intended for use in direct upconversion transmitters. The entire control loop was integrated in a CMOS UNITS transceiver chip. This paper presents the cancellation principle, simulations, and measurement results.
elib2cris::1512001600,lanschutzer2003
Keywords: 3G mobile communication; CMOS integrated circuits; circuit feedback; circuit simulation; integrated circuit design; integrated circuit measurement; integrated circuit modelling; radio transmitters

Integrated baseband and RF circuits for 2.5/3G mobile radio terminals - Stelzer, Andreas; Thomann, Wolfgang; Huemer, Mario; Hausner, Josef; Weigel, Robert (Applied Electromagnetics and Communications, 2003. ICECom 2003. 17th International Conference on, 2003)
The Global System for Mobile Communication (GSM) has set out to conquer the world. The power of this technology has dramatically changed the way of life in human society. This paper gives an overview of presently existing digital cellular standards (2G) and their convergence (2.5G) towords third-generation (3G) systems like the Universal Mobile Telephone System (UMTS). System requirements of the new generation of mobile phones are discussed in terms of baseband signal processing power and the impact on semiconductor technology. A highly integrated baseband processor is presented. In the second part of the paper challenges of the RF transceiver are treated by the fully-inlegrated, single-chip, intermediate frequency (IF) transceiver "Sushi Compact" with on-chip synthesizer, a vector-modulator/divider structure for receiver local oscillator (LO) generation, and by introducing a fully-integrated direct conversion transceiver SMARTiU. Tlie transceivers are intended for 3G Wide-Band Code Division Multiple Access (W-CDMA) mobiles and have been implemented in standard high frequency, Si-BiCMOS processes. Both transceivers comply wilh Association of Radio Industries and Businesses (ARIB) WCDMA and UMTS standards.
elib2cris::1512001600,stelzer2003c
Keywords: 3G mobile communication; Baseband; Circuits; Electromagnetics; GSM; Land mobile radio; Mobile communication; Multiaccess communication; Radio frequency; Transceivers

Integrated Classification and Localization of Targets using Bayesian Framework in Automotive Radars - Dubey, Anand; Santra, Avik; Fuchs, Jonas; Lübke, Maximilian; Weigel, Robert; Lurz, Fabian (2021 IEEE International Conference on Acoustics, Speech and Signal Processing, 2021)
Automatic radar based classification of automotive targets, such as pedestrians and cyclist, poses several challenges due to low inter-class variations among different classes and large intra-class variations. Further, different targets required to track in typical automotive scenario can have completely varying dynamics which gets challenging for tracker using conventional state vectors. Compared to state-of-the-art using independent classification and tracking, in this paper, we propose an integrated tracker and classifier leading to a novel Bayesian framework. The tracker’s state vector in the proposed framework not only includes the localization parameters of the targets but is also augmented with the targets’s feature embedding vector. In consequence, the tracker’s performance is optimized due to a better separability of the targets. Furthermore, the classifier’s performance is enhanced due to Bayesian formulation utilizing the temporal smoothing of classifier’s embedding vecto
Keywords: Automotive Radar; Bayesian Classification; Triplet Variational Auto-encoder; Unscented Kalman Filter

Integrated Classification and Tracking of Vulnerable Road Users using Automotive Radars - Dubey, Anand; Lurz, Fabian (IEEE Radio & Wireless Week, Workshop on AI-based Radar Technologies, 2022)

Integrated dielectric millimeter-wave sensors for biomedical applications (invited) - Lämmle, Benjamin; Schmalz, Klaus; Scheytt, Christoph; Weigel, Robert; Kissinger, Dietmar (Analog, 2011)
elib2cris::1512001600,laemmle2011c

Integrated Diversity Front-End for Digital Satellite Radio Reception - Röber, Jürgen; Senega, Simon; Bänisch, Andreas; Hagelauer, Amelie Marietta; Weigel, Robert; Lindenmeier, Stefan (IEEE MTT International Microwave Symposium (IMS), 2016)
This paper presents a diversity integrated circuit (IC) for digital satellite radio (SDARS) at 2.3GHz. The IC contains an RF circuit which enables fast adaptive processing of up to three antenna signals for maximum ratio combining in a fast fading scenario. The RF front-end of the diversity system is integrated using 150 nm CMOS technology. The phase of each of the three input paths can be adjusted in quantized steps of 45° from 0° to 360°. If the input signal of one path suffers from fading, a single path can be completely turned off for reducing the power consumption. The diversity IC is evaluated by means of laboratory measurements as well as by tests where antenna signals of real fading scenarios are processed using the presented IC. The results showa typical improvement in radio reception of more than a factor of 4 compared to a conventional reception system.
elib2cris::1512001600,roeber2016
Keywords: SDARS; Diversity; LNA; Phase Shifter; Power Combiner; Integrated Circuit; RF Front-end

Integrated Front-End Approaches for Wireless 100 Gb/s and Beyond: Enabling Efficient Ultra-High Speed Wireless Communication Systems - Carlowitz, Christian; Dietz, Marco (IEEE Microwave Magazine, 2023)
Wireless communication faces ever-growing demand for higher data rates, which has driven the need for modem implementations that are capable of providing single-link data rates on the order of 100 Gb/s and beyond for extremely fast data transmission. In recent years, the 60-GHz band has been employed to significantly increase wireless local area network data rates in IEEE’s 802.11ad standard targeting multigigabit modems. Its extension 802.11ay was finalized in 2021, targeting data rates toward 100 Gb/s in the same bands by increasing spectral efficiency and combining up to four channels with more than 8-GHz bandwidth in total [1] . This approach has the advantage of existing unlicensed regulatory allocations. Nevertheless, options for higher bandwidth have increasingly been investigated, also driven by the publication of the IEEE 802.15.3d [2] physical layer standard for a frequency range between 252 and 325 GHz, which resides in an atmospheric window that enables reasonable long-range communication links on the order of a few kilometers. In this frequency range, a substantially higher bandwidth is achievable. Specific regulatory allocations are still missing; nevertheless, the conditions to use this frequency range have already been discussed and described during the 2019 World Radiocommunication Conference [3] . Although the first demonstrations of 100-Gb/s modems in this frequency range were at least partially based on photonic technologies [4] , integrated front ends in different semiconductor technologies have been demonstrated [5] and are discussed in the present article in more detail together with the major remaining challenges for practical applications.<br
Keywords: Wireless communication; Wireless LAN; Spectral efficiency; Bandwidth; Modems; Transceivers; Resource management

Integrated millimeter-wave transceiver concepts and technologies for wireless multi-Gbps communication - Kissinger, Dietmar; Girg, Thomas; Beck, Christopher; Nasr, Ismail; Forstner, Hans-Peter; Wojnowski, Maciej; Pressel, Klaus; Weigel, Robert (IEEE MTT-S International Microwave Symposium, 2015)
elib2cris::1512001600,kissinger2015a

Integrated Reconfigurable CMOS Power Amplifiers - Rascher, Jochen; Zohny, Amr; Weigel, Robert (European Microwave Conference (EuMC), 2013)
Technologies for Embedded Wireless Systems Workshop
elib2cris::1512001600,rascher2013a

Integrated RF transformer and power combiner design in 150nm CMOS process - Lourandakis, Errikos; Karouzakis, Konstantinos; Papadopoulos, Padelis; Chicharro, José Antonio; Weigel, Robert (European Microwave Integrated Circuit Conference (EuMIC), 2014 9th, 2014)

Integrated System and Network Simulation of a 5.8 GHz Local Positioning System - Mosshammer, Ralf; Eickhoff, Ralf; Huemer, Mario; Weigel, Robert (12th International Conference, 2009)
In this work, performance aspects of a high-precision radiolocation system are evaluated. An integrated simulation environment is introduced, which allows the co-evaluation of both physical layer parameters, such as measurement error, as well as network-related performance figures like the time-to-fix and throughput. Simulation results for different strategies and algorithms are presented and analyzed for their practicability.
elib2cris::1512001600,mosshammer2009a

Integrated System-on-Module for Design-Space Exploration of Spiking Neural Networks - El-Masry, Moamen; Kourany, Taher; Kho, Rex; Werner, Thilo; Zjajo, Amir; Weigel, Robert (AICAS 2023 - IEEE International Conference on Artificial Intelligence Circuits and Systems, Proceeding, 2023)
We present an integrated system-on-module for design-space exploration of neurosynaptic behavior of complex, non-volatile memory enhanced, spiking neural networks. The system operates in a locally-analog, globally-digital manner, which enables both exploration and validation of individual computational components and characteristic spike-based features of neurosynaptic arrays. The system components are reconfigurable, adaptable and interchangeable enabling reproducible, precise firing patterns. The platform is coupled with an embedded resistive-RAM which acts as a weight retention mechanism. Experimental results obtained in 28 nm CMOS technology illustrate the feasibility of the methodology.
CRIS-Team Scopus Importer:2023-08-11
Keywords: near-memory computing; neuromorphic; non-volatile memory; resistive-RAM; Spiking neural networks; system-on-module

Integrated Systems-in-Package: Heterogeneous Integration of Millimeter-Wave Active Circuits and Passives in Fan-Out Wafer-Level Packaging Technologies - Hagelauer, Amelie Marietta; Wojnowski, Maciej; Pressel, Klaus; Weigel, Robert; Kissinger, Dietmar (IEEE Microwave Magazine, 2018)
Keywords: Antenna measurements; Dipole antennas; Integrated circuits; Packaging; Radio frequency; Silicon; Transceivers

Integrated Test Concepts for In-Situ Millimeter-Wave Device Characterization - Kissinger, Dietmar; Nehring, Johannes; Bauch, Andreas; Borutta, Karl; Nasr, Ismail; Lämmle, Benjamin; Weigel, Robert (IEEE 13th International New Circuits and Systems Conference (NEWCAS), 2015)
elib2cris::1512001600,kissinger2015b

Integrated Test for Silicon Front Ends - Kissinger, Dietmar; Lämmle, Benjamin; Maurer, Linus; Weigel, Robert (IEEE Microwave Magazine, 2010)
Silicon-based technologies have enabled the monolithic integration of transceiver circuits with operational frequencies up into the millimeter-wave regime. While high integration relaxes the requirements on RF chip-to-chip interconnects and external circuitry, it imposes serious challenges upon the traceability of failure mechanisms and functional errors of the individual building blocks that comprise the front-end. Additionally, expensive external measurement equipment in combination with complex, error-prone, and time-consuming calibration procedures, necessitates the development of on-chip test modules. It has been shown that a variety of built-in test schemes are currently the topic of research for both the mixed-signal and microwave domain. Solutions for the individual building blocks that will enable direct verification of performance parameters have been presented throughout this article. Current RF transceiver architectures will require a mixture of both paradigms for successful implementation of integrated test strategies. It is the authors' belief that the application of such concepts is a must for future integrated transceiver systems to meet the stringent requirements of time-to-market and low-cost of mass market consumer products.
elib2cris::1512001600,kissinger2010b
Keywords: Circuit testing; Integrated circuit interconnections; Integrated circuit technology; Millimeter wave integrated circuits; Millimeter wave measurements; Millimeter wave technology; Monolithic integrated circuits; Radio frequency; Silicon; Transceivers

Integration Concepts for SAW Duplexers for Multimode and Multiband RF Front-end Modules - Koch, Robert; Kiwitt, Jürgen; Pitschi, Maximilian; Wagner, Karl Christian; Weigel, Robert (Fourth International Symposium on Acoustic Wave Devices for Future, 2010)
elib2cris::1512001600,koch2010

Integration of Broadcast and Broadband in LTE/5G (IMB5) - Experimental Results From the eMBMS Testbeds - Heyn, Thomas; Morgade, Javier; Petersen, Swen; Pfaffinger, Kerstin; Lang, Ekkehard; Hertlein, Markus; Fischer, Georg (European Conference on Networks and Communications 2016, 2016)
In this paper, results of the project "Integration of Broadcast and Broadband in LTE/5G" (IMB5) project are described. The IMB5 project explores the LTE-broadcast mode eMBMS within two detailed SFN field trial networks in Erlangen and Munich, Germany and identifies potential improvements of the current broadcasting feature within LTE towards future releases of 4G and 5G. On the User Equipment (UE) side, terminals from Qualcomm and Samsung, based on commercial chipsets have been used mainly for application layer tests. For detailed physical layer tests, two different LTE software-defined-radio platforms based on OpenAirInterface framework and from National Instruments have been set-up to support detailed field experiments with the existing and future extended eMBMS beyond the state-of-the-art in LTE release 12. On the application layer, it is shown in the project, that using LTE eMBMS, a flexible service mix of unicast mobile broadband and broadcast linear TV can be delivered. For country wide deployment of eMBMS single-frequency networks, physical layer waveform modifications like an increased cyclic prefix compared to current LTE standard are recommended.
elib2cris::1512001600,heyn2016
Keywords: eMBMS; MBSFN; LTE-Broadcast 5G-Broadcast; Test facilities; Testbed; Field Trials; SDR platform

Integration of Cellular Internet of Things Modules into Sport Wearable - Elhaddad, Ahmed; Irnstorfer, Florian; Duemler, Burkhard; Fischer, Georg (European Technology Platform on Smart Systems Integration (EPoSS), 2021)
Narrowband Internet of Things (NB-IoT) and LTE for Machine Type Communications (LTE-M) are gaining more momentum as Cellular Internet of Things (CIoT) technologies, which provide cellular connectivity for IoT applications. Thus, mobile operators can support IoT applications by exploiting the existing network infrastructure. These standards are designed to provide large coverage area, low energy consumption devices and low cost devices. In our project, we are integrating sensors, NB-IoT and LTE-M modules into smart wearables namely: a NB-IoT module into a Smart Shoe and a NB-IoT/LTE-M module into a Smart Jacket. Therefore, sensor data are transmitted to a cloud platform directly without using a smartphone as a hub node (“phoneless” solution). This will allow for health monitoring of athletes during activities and during their recovery phase in case of rehabilitation and injury prevention. <

Integration of Molecular Communications into Future Generation Wireless Networks - Haselmayr, Werner; Springer, Andreas; Fischer, Georg; Alexiou, Christoph; Boche, Holger; Höher, Peter Adam; Dressler, Falko; Schober, Robert (6G Wireless Summit, 2019)

Integration of Satellite Navigation RF Receiver Paths into Mobile Radio Platforms - Miskiewicz, Anna (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2009)

Integration spannungsabstimmbarer Oszillatoren für Mobilfunkanwendungen - Zannoth, Markus; Fenk, Josef; Weigel, Robert (Elektrotechnik und Informationstechnik, 1998)
Die in Handfunkgeraten der GSM- und DECT-Mobilfunksysteme benutzten Frequenzerzeugerkonzepte beruhen im wesentlichen auf dem Einsatz dreier von dem Sende- und Empfangssynthesizer angesteuerten abstimmbaren Oszillatoren. Ziel der gegenwärtigen Arbeiten ist die Integration dieser Oszillatoren in bipolarer Technik. In dem Beitrag werden die Anforderungen der Oszillatoren aufgezeigt. Die Erhöhung des Integrationsgrades der Oszillatoren wird theoretisch und experimentell untersucht. Für GSM-Anwendungen werden teilintegrierte und für DECT-Anwendungen vollintegrierte VCO-Varianten demonstriert.
elib2cris::1512001600,zannoth1998

Integrierte Antennen in eWLB-Gehäusen für Millimeterwellenanwendungen - Pour Mousavi, Seyed Mehran (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2014)

Integrierte Radar Sensoren in Silizium-Germanium Technologie für den Automobilbereich - Kissinger, Dietmar; Weigel, Robert (HF-Report, 2010)
elib2cris::1512001600,kissinger2010a

Integrierter Generator zur Erzeugung hochlinearer und ultrabreitbandiger Frequenzrampen zur Nahbereichsortung - Maser, Matthias (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2017)

Integrity-sensing based on surface roughness of copper conductors for future use in natural fiber composites - Baron, Philipp; Lenz, Philipp; Wittmann, Armin; Fischer, Georg (IEEE Sensors Letters, 2021)
Natural fiber composites can significantly contribute to the necessary reduction of CO2 emissions. Because of scattering material characteristics caused by variation in plant growth, it is necessary to measure the attrition of the derived natural fiber composite material in-situ. This monitoring will be implemented with the aid of a new type of copper line sensor embedded in the flax fiber grid. The line sensor, which will be integrated into the natural fiber composite, will provide information about the remaining service life of the composite material and thus monitor the component’s structural integrity. The key property of copper is the formation of surface roughness under mechanical strain. In this paper proof is provided, that all relevant forms of mechanical strain generate surface roughness on copper conductors. When the mechanical load capacities of conductor and natural fiber composite are matched, it is possible to generate a statement about the composite’s remaining service life via an evaluation of the roughness. The feasibility of matching is proven by two methods which allow to vary the mechanical sensitivity of the copper conductor to mechanical stress. This allows the deployment of the sensor in manifold load scenarios and thus the use of flax fiber composite materials for critical automotive parts.<br
Keywords: Copper; surface roughness; Line Sensor; natural fiber composite material; Cable Monitoring System; skin effect

Intelligente Funkmikrofone - Spektrumserfassung für Cognitive-Radio-Systeme - Rieß, Steffen; Brendel, Johannes; Schröter, Simon; Fischer, Georg (2013)
Die Hersteller von professioneller, drahtloser Produktionstechnik sehen sich zunehmend mit steigenden Anforderungen für den interferenzfreien Betrieb ihrer Systeme konfrontiert. Die Gründe dafür liegen in der Digitalen Dividende sowie Änderungen in der Regulierung durch die Bundesnetz-agentur im Frequenzbereich von 470-862 MHz. Ein Ansatz zur Lösung dieser Problematik stellt die Cognitive-Radio-Technologie dar, wobei die vorherrschende Funkumgebung überwacht und daraus ggf. die Entscheidung für einen Frequenzwechsel im Falle einer Störung getroffen wird.
elib2cris::1512001600,riess2013a

Intelligente Gassensorik-Plattform - Präsenzdetektion in Innenräumen mittels CO2 zur Erhöhung der Sicherheit im betreuten Wohnen - Zimmermann, Lars (EEEfCOM, 2013)

Intelligente LED-Leuchte für die Funktionsbereiche „Fressen“, „Liegen“ und „Laufen“ in der Milchviehhaltung - Werner, Daniel; Müller, Maike; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (BLE Innovationstage 2016, 2016)

Intelligente LED-Leuchte für die Funktionsbereiche „Fressen, „Liegen“ und „Laufen“ in der Milchviehhaltung - Werner, Daniel; Müller, Maike; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (4. Düsser Milchviehforum, 2017)

Intelligentes Frequenzmanagement bei professionellen Drahtlosmikrofonen (PMSE) - Eine Reaktion auf die Herausforderung durch die Digitale Dividende - Zimmermann, Lars (RADCOM, 2011)
elib2cris::1512001600,zimmermann2011a

Intelligent Signal Processing Routine for Instantaneous Heart Rate Detection using a Six-Port Microwave Interferometer - Will, Christoph; Shi, Kilin; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (IEEE International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS), 2015)
Instantaneous heart rate detection is one of the key parameters in medical vital parameter monitoring. In medical centers e.g., real time monitoring of the vital signs of a patient under surveillance is necessary. Nowadays, the dominant technologies are electrocardiogram (ECG) or ballistocardiogram (BCG), but the required direct contact to the person-under-surveillance is a common drawback of these sensors. In this paper, a Six-Port microwave interferometer is presented and used to detect the current heart rate of a person-under-test. An intelligent signal processing routing is proposed, that avoids the fast Fourier transform (FFT) due to the implicated longsome observation window and operates directly in the time domain instead. A commercial ECG product is used to proof the reliability of the presented signal processing routine to establish Six-Port microwave interferometers for instantaneous heart rate detectio
elib2cris::1512001600,will2015
Keywords: Six-Port; Interferometers; Biomedical signal processing; Heartbeat monitoring

Intelligent surface-Aided transmitter architectures for millimeter-wave ultra massive mimo systems - Jamali Kooshkghazi, Vahid; Tulino, Antonia M.; Fischer, Georg; Müller, Ralf; Schober, Robert (IEEE Open Journal of the Communications Society, 2021)
In this article, we study two novel massive multiple-input multiple-output (MIMO) transmitter architectures for millimeter wave (mmWave) communications which comprise few active antennas, each equipped with a dedicated radio frequency (RF) chain, that illuminate a nearby large intelligent reflecting/transmitting surface (IRS/ITS). The IRS (ITS) consists of a large number of low-cost and energy-efficient passive antenna elements which are able to reflect (transmit) a phase-shifted version of the incident electromagnetic field. Similar to lens array (LA) antennas, IRS/ITS-Aided antenna architectures are energy efficient due to the almost lossless over-The-Air connection between the active antennas and the intelligent surface. However, unlike for LA antennas, for which the number of active antennas has to linearly grow with the number of passive elements (i.e., the lens aperture) due to the non-reconfigurablility (i.e., non-intelligence) of the lens, for IRS/ITS-Aided antennas, the reconfigurablility of the IRS/ITS facilitates scaling up the number of radiating passive elements without increasing the number of costly and bulky active antennas. We show that the constraints that the precoders for IRS/ITS-Aided antennas have to meet differ from those of conventional MIMO architectures. Taking these constraints into account and exploiting the sparsity of mmWave channels, we design two efficient precoders; one based on maximizing the mutual information and one based on approximating the optimal unconstrained fully digital (FD) precoder via the orthogonal matching pursuit algorithm. Furthermore, we develop a power consumption model for IRS/ITS-Aided antennas that takes into account the impacts of the IRS/ITS imperfections, namely the spillover loss, taper loss, aperture loss, and phase shifter loss. Moreover, we study the effect that the various system parameters have on the achievable rate and show that a proper positioning of the active antennas with respect to the IRS/ITS leads to a considerable performance improvement. Our simulation results reveal that unlike conventional MIMO architectures, IRS/ITS-Aided antennas are both highly energy efficient and fully scalable in terms of the number of transmitting (passive) antennas. Therefore, IRS/ITS-Aided antennas are promising candidates for realizing the potential of mmWave ultra massive MIMO communications in practice.
CRIS-Team Scopus Importer:2022-06-05
Keywords: and energy efficiency; hybrid MIMO; Intelligent reflecting/transmitting surfaces; lens array; mmWave communications; reflect/transmit array; scalability

INTMDCT - A Link Between Perceptual and Lossless Audio Coding - Geiger, Ralf; Herre, Jürgen; Koller, Jürgen; Brandenburg, Karlheinz (IEEE ICASSP, 2001)
Vorträge und Veröffentlichungen auf Konferenzen_Gehörangepasste Datenreduktion

Introducing New Design Guidelines for Dualband CRLH Structures formed by Transmission Lines and Lumped Components - Kölpin, Alexander; Pape, Benedikt; Weigel, Robert (IEEE MTT-S International Microwave Workshop on Wireless Sensing, Local Positioning, and RFID, 2009)
In this paper a new strategy for designing dualband composite right and left handed (CRLH) structures based on lumped elements is introduced. By using the presented formulars the desired metamaterial devices become easily scalable to arbitrary frequencies as the parasitic elements of the lumped components are considered resulting in three design guidelines. The practical use is shown by a dualband branch line coupler and a Wilkinson power divider operating at 2.5 GHz and 5.25 GHz.
elib2cris::1512001600,koelpin2009
Keywords: Wilkinson power divider; dualband CRLH structure design guideline; dualband branch line coupler; dualband composite-right-and-left-handed structure; lumped component; metamaterial device; parasitic element; transmission line; UHF couplers; lumped parameter networks; metamaterials; microwave materials; power dividers; telecommunication transmission lines

Introduction in High-Resolution and Ultra-Low Power Distance Measurements by Microwave Interferometry - Kölpin, Alexander; Lurz, Fabian; Weigel, Robert (IEEE International Microwave Symposium, Workshop on Modern radar systems for high resolution ranging, indoor localization, and vital signs detection, 2015)
Many civilian measurement applications can be realized by microwave interferometry. This radar architecture features low hardware and software complexity and can be optimized for highest distance resolutions in the micrometer regime combined with a measurement value update rate of several kilohertz or ultra-low power operation for, e.g., presence detection. Both approaches will be discussed in this talk. After introducing the basic technology and dependencies a detailed introduction to real hardware building blocks for the K band will be given. Also non-ideal effects and approaches for calibrating the system will be given. The talk will close with real world applications spreading from simple presence detection to precise distance measurements, vibration analysis and frequency determinatio
elib2cris::1512001600,koelpin2015
Keywords: Radar; Interferometry

Introduction to High-Resolution Distance Measurements by Microwave Interferometry - Kölpin, Alexander (Workshop on Industrial Radar Technologies, 2014)
Keywords: Six-Port; Interferometer

Investigation of DC-Offset and Flicker Noise for Combined Single Shot Galileo/GPS Receivers with Homodyne Front-End Architecture - Ehm, Henning; Winter, Sebastian; Weigel, Robert (IEEE Radio and Wireless Symposium (RWS), 2008)
This paper presents quantitative theoretical and simulative results on the sensitivity of a combined single shot Galileo/GPS receiver with homodyne front-end architecture due to DC-offset, flicker noise, and resolution of the analog to digital converter.
elib2cris::1512001600,ehm2008

Investigation of Parasitic Effects in Multi-Transducer SAW RF Filters - Fischerauer, Gerhard; Gogl, Dietmar; Weigel, Robert; Russer, Peter (IEEE Ultrasonics Symposium, 1994)
This paper discusses the relative importance of the different parasitic effects in multi-transducer SAW filters at UHF frequencies. This is accomplished by using a lumped-element circuit model which links the circuit elements directly to the filter-geometry and enables one to identify the sources of unwanted features in the filter frequency characteristics. Further, the model complexity may be reduced by retaining only those circuit elements that lead to the most severe effects. It is shown how Ohmic losses in connection pads and bond wires, coupling capacitances between pads, and inductive effects due to the bond wires are modeled and how they contribute to the filter characteristics. An experimental interdigitated IDT (IIDT) filter consisting of 15 transducers and operational at 1 GHz serves as an example. Its passband distortions could easily be traced back to stray capacitances between pads or IDTs while the stopband characteristics are mainly determined by inductive coupling effects between the 17 bond wires. The latter result indicates that in multi-transducer devices like IIDT filters or image-impedance connected twin-track filters parasitic effects negligible in simpler structures are of paramount importance
elib2cris::1512001600,fischerauer1994b

Investigation of Particle Steering for Different Cylindrical Permanent Magnets in Magnetic Drug Targeting - Thalmayer, Angelika; Zeising, Samuel; Fischer, Georg; Kirchner, Jens (7th International Electronic Conference on Sensors and Applications, 2020)
Keywords: magnetic drug targeting; particle steering; permanent magnet

Investigation of SAW propagation loss - Wallner, Paul; Holm, Andreas; Weigel, Robert (Proc Progressin Electromagnetics Research Symposium (PIERS), 1997)
elib2cris::1512001600,wallner1997

Investigation of surface acoustic waves on LiNbO3, quartz, and LiTaO3 by laser probing - Holm, Andreas; Stürzer, Quirin; Xu, Y.; Weigel, Robert (Microelectronic Engineering, 1996)
Laser probing for the investigation of surface acoustic wave (SAW) devices has been established on account of some important advantages. Nondestructive testing and phase preserved imaging of the wave field yield valuable information for evaluation of the material data. In the following, results from high accuracy phase velocity measurements on SAW-cut crystals, e.g. 128°-YX-LiNbO3 and ST-quartz will be presented. Moreover it is shown the detection of leaky surface acoustic waves (LSAW) on 36°-YX-LiTaO3, which is a wave mainly polarized parallel to the surface plane. However, high sensitivity of the measurement system enables the detection of the weak bending perpendicular to the surface.
elib2cris::1512001600,holm1996a
Keywords: surface; acoustic; wave; LiNbO3; laser; probing; SAW

Investigation of Systematic Errors of an Indirect Resonant Planar Material Characterization Method - Lau, Isabella; Weigel, Robert (IEEE Transactions on Microwave Theory and Techniques, 2022)
Indirect measurement principles have always been presented as a solution to save simulation and modeling efforts for complex permittivity extraction methods. However, detailed investigations on remaining systematic errors as well as recommendation guidelines for reference material selection are missing in the literature. In this article, typical systematic error sources of a planar coplanar waveguide over ground material sensor are investigated. An indirect error compensation algorithm is presented, and its ability to compensate the main error sources is simulatively analyzed. A measurement setup is created by considering the specified requirements. The measurement principle is validated by measuring three different plastics. Overall, the results are plausible and have uncertainties of the same or lower order of magnitude compared with the state of the art. However, the findings show that indirect planar methods suffer from fundamental problems, which limit the achievable measurement uncertainty. The findings of this work can be used as a basis for decision-making when considering an indirect planar measurement principle.
CRIS-Team WoS Importer:2022-05-13

Investigation of Thermal and Non-Linear Effects on the Performance of the Power Amplifier - BAW Filter - Chain in a LTE Transmitter - Stehr, Uwe; Chauhan, Vikrant; Silva Cortes, Victor Arturo; Frank, Astrid; Hein, Matthias; Weigel, Robert; Hagelauer, Amelie Marietta (International Ultrasonics Symposium, 2019)

Investigation on Third-Order Intermodulation Distortions due to Material Nonlinearities in TC-SAW Devices - Chauhan, Vikrant; Mayer, Markus; Ruile, Werner; Wagner, Karl; Mayer, Andreas; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2018)

Investigations of a New Design Concept for Wide-Band Hybrid Ladder Filters - Wagner, Michael; Gossmann, Timo; Tomasik, Jakob; Weigel, Robert; Hagelauer, Amelie (IEEE International Ultrasonics Symposium, IUS, 2019)
In this paper, a new design concept for wide-band hybrid ladder filters is investigated. The concept enables manipulation of the fixed behavior and limited electromechanical coupling coefficient (keff2) of acoustic-wave resonators by additional lumped-element resonators. This hybrid approach allows for resonance spreading of single acoustic-wave resonators, which corresponds to an increased keff2. An illustration of the concept is given, as well as an example for the application to wide-band filter design. Measurements of one of two proposed basic structures show an effective increase of keff2 by a factor of more than 4, demonstrating that the concept is feasible in practice.
CRIS-Team Scopus Importer:2020-02-21

Investigations on the Magnetic Field Coupling of Automotive High Voltage Systems to Determine Relevant Parameters for an EMR-optimized Designing - Krause, David; John, Werner; Weigel, Robert (Advances in Radio Science : Kleinheubacher Berichte, 2016)
elib2cris::1512001600,krause2014

In-vitro Evaluation von endoskopischer Oberflächenrekonstruktion mittels Time-of-Flight-Kameratechnik - Groch, Anja; Hempel, Sarah-Marie; Speidel, Stefanie; Höller, Kurt Emmerich; Engelbrecht, Rainer; Penne, Jochen; Seitel, Alexander; Röhl, Sebastian; Yung, Kwong; Bodenstedt, Sebastian; Pflaum, Felix; Kilgus, Thomas; et al. (Workshop Bildverarbeitung für die Medizin, 2011)
UnivIS-Import:2015-04-16:Pub.2011.tech.IE.LEH.invitr

IP2 and DC Offset Tuning in Current Mode Output Downconversion Mixers - Dufrene, Krzysztof; Weigel, Robert (International Conference on Microwaves, Radar Wireless Communications, 2006, 2006)
This paper describes IP2 and DC offset tuning methods for current mode output downconversion mixers, which are suitable for low-voltage RFIC applications. A prototype of a 1.5 V double-balanced I/Q mixer for cellular applications operating in a 700 MHz - 2200 MHz, frequency range, equipped with the calibration circuits and fabricated in a 0.13 um RF CMOS technology, is presented. Experimental results confirm the effectiveness of the proposed tuning approach.
elib2cris::1512001600,dufrene2006d
Keywords: Baseband; CMOS technology; Calibration; Circuit optimization; Intermodulation distortion; Noise reduction; Output feedback; Radio frequency; Tuning; Voltage

I/Q Imbalance Compensation for Six-Port Interferometers in Radar Applications - Linz, Sarah; Vinci, Gabor; Lindner, Stefan; Mann, Sebastian; Lurz, Fabian; Barbon, Francesco; Weigel, Robert; Kölpin, Alexander (European Microwave Conference, 2014)
Six-port interferometers are of great interest for displacement and vibration measurements in industrial as well as medical applications. However, they show offsets as well as amplitude and phase imbalances in their differential in-phase and quadrature signals, leading to inaccuracies of the measured displacement. If a very slow moving or vibrating target has to be monitored, an additional phase shifter for calibration is needed, so that the system’s errors can be compensated. A method for calculation and compensation of errors is presented and a compact and cost-efficient implementation of a phase shifter for 24 GHz Six-port interferometers is shown.
elib2cris::1512001600,linz2014b
Keywords: Six-Port; Ellipse; IQ Imbalance; Interferometer

Iterative combined decision feedback equalization and decoding for broadband wireless single carrier systems - Koppler, Alois; Huemer, Mario; Springer, Andreas; Weigel, Robert (Telecommunications, 2003. ICT 2003. 10th International Conference on, 2003)
Single carrier transmission with frequency domain equalization (SC/FDE) exhibits approximately the same performance and signal processing complexity as orthogonal frequency division multiplexing (OFDM) for broadband wireless access (BWA) systems or W-LANs. We propose the extension with low complexity iterative decision feedback equalization and decoding for conventional blockwise SC/FDE transmission. The described turbo-like scheme approximately achieves the efficiency of ideal decision feedback equalization. We also demonstrate that the feedback of softly decided symbols before the first decoding step provides an extra gain. Simulation results show a remarkable performance increase for highly frequency selective multipath channels.
elib2cris::1512001600,koppler2003
Keywords: OFDM; WLAN; broadband wireless single carrier systems; frequency domain equalization; frequency selective multipath channels; iterative combined decision feedback equalization; iterative decoding; low complexity DFE; orthogonal frequency division multiplexing; signal processing complexity; simulation results; single carrier transmission; softly decided symbols; broadband networks; decision feedback equalisers; iterative decoding; multipath channels; radio access networks; wireless LAN

Iterative methods for reluctance based PEEC Models - Zitzmann, Martin-Ludwig; Clees, Tanja; Weigel, Robert (Proceedings of the 17th Zurich Symposium on Electromagnetics Compatibility, 2006)
elib2cris::1512001600,zitzmann2006a

Key generation based on accleration data of shaking processes - Bichler, Daniel; Stromberg, Guido; Huemer, Mario; Löw, Manuel (Proceedings of the 9th international conference on Ubiquitous computing, UbiComp 2007: Ubiquitous Computing UbiComp, 2008)
Hard restrictions in computing power and energy consumption favour symmetric key methods to encrypt the communication in wireless body area networks which in term impose questions on effective and user-friendly unobtrusive ways for key distribution. In this paper, we present a novel approach to establish a secure connection between two devices by shaking them together. Instead of distributing or exchanging a key, the devices independently generate a key from the measured acceleration data by appropriate signal processing methods. Exhaustive practical experiments based on acceleration data gathered from real hardware prototypes have shown that in about 80% of the cases, a common key can be successfully generated. The average entropy of these generated keys exceed 13bits.
elib2cris::1512001600,bichler2008

Klasse-E Leistungsverstärker mit Lastmodulation - Lautenbacher, Thomas; Schmidt, Christian; Fehr, Matthias; Kamper, Michael; Weigel, Robert; Fischer, Georg; Kölpin, Alexander (EEEfCOM 2012, 2012)
elib2cris::1512001600,lautenbacher2012a

Kognitives Frequenzmanagement für professionelle Drahtlosmikrofone (PMSE) mittels eines Scanempfänger-Netzwerks - Zimmermann, Lars (EEEfCOM, 2011)
elib2cris::1512001600,zimmermann2011

Kognitives Spektrumsmanagement fuer professionelle Funkmikrofone (PMSE) - ETSI STF386 - Fischer, Georg (Electrical and Electronic Engineering for Communication Workshop - Entwicklerforum - Fachmesse, 2011)
elib2cris::1512001600,fischer2011

Kollineare akutooptische Ablenker auf Ti:LiNbO3-Wellenleitern - Weigel, Robert (Proc. 3. Kolloquium Integrierte Optik der Deutschen Forschungsgemeinschaft, 1988)
null::1512001600,weigel1988

Kontinuierliche berührungslose Erfassung von Herzschlag und Atmung als Surrogatparameter für Symptomlinderung–eine Pilotstudie - Steigleder, Tobias; Malessa, Anke; Shi, Kilin; Michler, Fabian; Schellenberger, Sven; Heckel, Maria; Kölpin, Alexander; Ostgathe, Christoph (Zeitschrift für Palliativmedizin, 2018)
Fokus der Palliativmedizin (PM) ist die persönliche Begegnung. Häufig wird bei schwerer Krankheit auf apparative Therapie und Diagnostik verzichtet. Dennoch könnten Biomarker (BM, zB Herz-und Atemfrequenz) wichtige ergänzende Hinweise auf Symptomlast und zur individuellen Anpassung der medikamentösen Behandlung geben. Wir erforschen den innovativen Ansatz, BM mit Radartechnologie (RT) berührungs-und belastungsfrei zu erfassen. Ziel soll es ua in sein, in Zukunft die Symptomlinderung zu verbessern. RT, die auf einem interferometrischem Verfahren beruht, erfasst Herzschläge und Atmung mittels Messung der Distanzänderung zu der Radarantenne aus einigen Metern Entfernung und durch Materialen wie Kleidung oder Bettdecke hindurch. Lernende Algorithmen extrahieren die spezifischen Signale und werten sie automatisiert au

Konzept eines Netzwerks zur Spektrumsbeobachtung für C-PMSE-Systeme - Rieß, Steffen; Brendel, Johannes (RADCOM 2012 - Radar and Communication, 2012)
elib2cris::1512001600,riess2012

Kooperationsprojekt C-PMSE - Cognitive Program Making and Special Events - Zimmermann, Lars (BICC OpenLabs, 2012)
elib2cris::1512001600,zimmermann2012

Koplanare hochtemperatursupraleitende Hochfrequenzkomponenten - Weigel, Robert; Valenzuela, Alejandro; Russer, Peter (Proc. Kleinheubacher Tagung, 1993)
elib2cris::1512001600,weigel1993c

LABEL-AWARE RANKED LOSS FOR ROBUST PEOPLE COUNTING USING AUTOMOTIVE IN-CABIN RADAR - Servadei, Lorenzo; Sun, Huawei; Ott, Julius; Stephan, Michael; Hazra, Souvik; Stadelmayer, Thomas; Lopera, Daniela Sanchéz; Wille, Robert; Santra, Avik (ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings, 2022)
In this paper, we introduce the Label-Aware Ranked loss, a novel metric loss function. Compared to the state-of-the-art Deep Metric Learning losses, this function takes advantage of the ranked ordering of the labels in regression problems. To this end, we first show that the loss minimises when datapoints of different labels are ranked and laid at uniform angles between each other in the embedding space. Then, to measure its performance, we apply the proposed loss on a regression task of people counting with a short-range radar in a challenging scenario, namely a vehicle cabin. The introduced approach improves the accuracy as well as the neighboring labels accuracy up to 83.0% and 99.9%: An increase of 6.7% and 2.1% on state-of-the-art methods, respectively.
Created from Fastlane, Scopus look-up
Keywords: Deep Metric Learning; People Counting; Radar Signal Processing

Lab-on-a-chip in a pocket with droplet mixing - Bartunik, Max; Kirchner, Jens (Microfluidics 2022, 2022)

LabVIEW basierte Echtzeit-Signalverarbeitung für Low-Power-Radarsensorik - Lurz, Fabian; Mann, Sebastian; Linz, Sarah; Lindner, Stefan; Weigel, Robert; Kölpin, Alexander (Virtuelle Instrumente in der Praxis 2015, 2015)
Hochfrequenz-Radarsensoren haben sich in letzter Zeit als eine vielversprechende Alternative zu herkömmlichen Anwesenheitssensoren wie Passiv-Infrarot oder Ultraschall bewährt. Aufgrund ihrer hohen Ortsauflösung können Radarsysteme eine drahtlose Detektion von Vitalparametern, wie Herzschlag oder Atmung, durchführen und so auch sich nicht bewegende Personen detektieren. Dieses Dokument beschreibt die LabVIEW basierte Signalverarbeitung für ein 24 GHz Low-Power-Radarsystem. Für eine effiziente Evaluierung der Detektionsalgorithmen müssen diese unter weichen Echtzeitbedingungen ausgeführt werden, um ein verzögerungsfreies und flüssiges Feedback der graphischen Oberfläche zu erhalten.
elib2cris::1512001600,lurz2015a

Large-signal measurements and non-linear characterization of an analog frontend for passive UHF CMOS RFID transponders - Essel, Jochen; Brenk, Daniel; Heidrich, Jürgen; Weigel, Robert; Kissinger, Dietmar (IEEE Transactions on Microwave Theory and Techniques, 2013)
elib2cris::1512001600,essel2013

Large-Signal Performance Optimization of Inverted-F Antenna Tuned by Switchable RF Capacitor - Solomko, Valentyn; Özdamar, Oguzhan; Weigel, Robert; Hagelauer, Amelie (2021 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications, APWC 2021, 2021)
Harmonics emission by an aperture-tuned IFA (inverted-F antenna) is studied. The analytical analysis is conducted using a transmission-line model of the antenna. Based on the results of analysis, an optimization example for the large-signal performance of a carrier-aggregation front-end tuned by a high-voltage switchable RF capacitor is presented, the findings are supported by the measurements on a hardware demonstrator. According to the experimental results, the power of a second harmonic at 1800 MHz coupled from the main into diversity antenna is reduced by 10 dB by fine-selecting the position of the capacitor-based tuning network along the radiating element of the main antenna.
CRIS-Team Scopus Importer:2021-10-15
Keywords: antenna tuning; aperture tuning; C-tuner; carrier aggregation; cellular user equipment; harmonics; high-voltage RF switch; inverted-F antenna; RF switch; switchable capacitor; user terminal

Laseroptische Charakterisierung mikroakustischer Bauelemente - Holm, Andreas; Weigel, Robert (Informationstagung Mikroelektronik, 1997)
elib2cris::1512001600,holm1997a

Laseroptisches Messsystem zur Charakterisierung von mikroakustischen Bauelementen - Holm, Andreas; Thomann, Wolfgang; Weigel, Robert (Proc. Kleinheubacher URSI/ITG-Tagung, 1995)
elib2cris::1512001600,holm1995

Laser probing system for the accurate detection of surface acoustic wave phase velocities - Holm, Andreas; Soelkner, Gerald; Ruile, Werner; Russer, Peter; Weigel, Robert (SPIE 2115, 1994)
The present work demonstrates a high-resolution technique for the optical detection of the phase and amplitude of high frequency surface acoustic waves (SAWs). The test setup incorporates a mode-locked picosecond laser, harmonic mixing, and coherent detection, and it allows not only the measurement of the surface wave field but also the direct determination of the phase velocity. A measurement bandwidth in excess of 2 GHz is achieved. The maximum scan length was 4 cm. As a substrate, LiNbO3 has been used for the test measurements. Minimum detectable surface displacement and dynamic range were 1 pm/Hz1/2 and 40 dB, respectively. The method enables the determination of the phase velocity with a resolution of 1.5 (DOT) 10-5 in dependence of crystal cut, temperature, and frequency. An additional feature is that phase velocity values can be obtained with spatial resolution, i.e., velocity variation effects along the propagation path can be evaluated. We found that the assumption that the SAW velocity is constant across the whole device surface is not valid in general.
elib2cris::1512001600,holm1994a

Laufzeitdifferenz- und Richtungsschätzverfahren zur Ortung von GSM-Mobiltelefonen - Zimmermann, Lars (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2010)
elib2cris::1512001600,zimmermann2010
Keywords: Localization; Algorithms

LC Tank Differential Inductor-Coupled Dual-Core 60 GHz Push-Push VCO in 45 nm RF-SOI CMOS Technology - Rimmelspacher, Johannes; Weigel, Robert; Hagelauer, Amelie Marietta; Issakov, Vadim (Radio & Wireless Week (RWW): Silicon Monolithic Inegrated Circuits in RF Systems (SiRF), 2019)
This paper presents a 60 GHz dual-core push-push VCO in a 45 nm partially depleted (PD) RF Silicon-on-Insulator (SOI) CMOS technology. The cores are coupled inductively via differential inductors. The best measured phase noise at 1 MHz offset from a 63 GHz carrier is −94.4 dBc/Hz. The wideband continuous frequency-tuning-range (FTR) is 16 %. The DC power dissipation is 76 mW including fundamental 30 GHz and second harmonic (H2) 60 GHz output buffers at 1 V power supply voltage. The measurement results of a reference single-core VCO design proves the relative phase noise improvement of the implemented core-coupling technique. The chip area excluding pads is 0.09 mm2.<br
Keywords: millimeter-wave VCO; wideband; silicon-on-insulator; CMOS technology; System-on-Chip

LDPC codes: An Efficient Error Control Technique for Embedded Systems - Lunglmayr, Michael; Huemer, Mario (FH Science Day 2008, 2008)
elib2cris::1512001600,lunglmayr2008c

Lead Acid Accumulator Modelling for High Frequency Simulation Applications - Haslinger, Friedrich; Weigel, Robert (Annual Vehicle Electronic Systems Conference, 2000)
elib2cris::1512001600,haslinger2000

Learning Representations for Neural Networks Applied to Spectrum-Based Direction-of-Arrival Estimation for Automotive Radar - Gall, Maximilian; Gardill, Markus; Fuchs, Jonas; Horn, Thomas (2020 IEEE MTT-S International Microwave Symposium (IMS), 2020)
This paper proposes a new approach to Direction-of-Arrival Estimation using Artificial Neural Networks. It is capable of estimating both, model-order and azimuth DoA in a single step. In a hybrid approach, we train on synthetic data generated from a signal model and validate on data obtained through a measurement setup. We show a proof-of-concept for the hybrid approach, validated with measurement data. Advances on the exactness of the signal model enable the trained ANN to handle real-world data out-of-the-box. Our findings indicate super-resolution performance and the capability of estimating even high model-orders while significantly reducing computation time.<br

LED als Lichtquelle im Stall - Reiter, Klaus; Müller, Maike; Werner, Daniel (Weiterbildungskurs für Baufachleute 2015, 2015)

LED Basiswissen für Innen- und Außenraum - Schwenzfeier-Hellkamp, Eva; Werner, Daniel (5. Fachaustausch der Stadt Werther, 2017)

LED-Beleuchtung für Mensch und Tier in einem Milchviehstall unter Berücksichtigung der biologischen Wirksamkeit - Werner, Daniel; Schneider, Michael; Müller, Maike; Schwenzfeier-Hellkamp, Eva; Reiter, Klaus (Licht 2016, 22. Gemeinschaftstagung der lichttechnischen Gesellschaften Deutschlands, der Niederlande, Österreichs und der Schweiz, 2016)

LED-Beleuchtung in der Nutztierhaltung - Müller, Maike; Reiter, Klaus; Werner, Daniel (Der energieeffiziente Bauernhof, 2016)

LED - das neue Licht am Bauernhof - Werner, Daniel; Müller, Maike; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (Energieeffizienz und e-Mobilität in der Landwirtschaft – Innovative Energiesparlösungen für die Zukunft, 2016)

LED Leitstein: Eine beleuchtete Orientierungshilfe für Sehbehinderte im öffentlichen Straßen-raum - Werner, Daniel; Gabel, Kristin; Schwenzfeier-Hellkamp, Eva (12. ETP Kongress Straßenbeleuchtung 2013, 2013)

LED-Leuchten: Auch für den Kuhstall geeignet? - Werner, Daniel (2013)

LED-Leuchten im Milchviehstall bedarfsorientiert einsetzen - Werner, Daniel; Eßelmann, Christian; Greif, Maike; Bernhart, Kristin; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (Workshop Rinderhaltung und Stallbau für Architekten, Berater und Betreuer, 2018)

LEDs im Milchviehstall, worauf kommt es an? - Werner, Daniel; Schneider, Michael; Müller, Maike; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (2016)

LED-Teststrecke im Klimapark Rietberg Messtechnische Untersuchung moderner und energiesparsamer LED Beleuchtungstechnik im Bereich der Straßenbeleuchtung - Held, Sascha; Werner, Daniel; Schwenzfeier-Hellkamp, Eva (2013)

Legal Distribution of Music through the Internet - Rump, Niels; Herre, Jürgen; Brandenburg, Karlheinz; Koller, Jürgen (106th AES Convention, 1999)
herre_papers_secure_delivery_of_multimedia_data

Leistungsverstärker mit Transistoren und ihre Linearisierung - Power amplifiers with transistors and their linearization - Fischer, Georg (CCG-Seminar SE2.02, Basics of Microwave Technology for Communications and Radar applications, 2005)
elib2cris::1512001600,fischer2005a
Keywords: PA

Lens-based 77 GHz MIMO Radar for Angular Estimation in Multitarget Environments - Lutz, Steffen; Walter, Thomas; Weigel, Robert (International Journal of Microwave and Wireless Technologies, 2014)
The demanding tasks for automotive radar systems in multitarget scenarios require an increased target separation performance and new sensor concepts. In this contribution, a highly integrated 77 GHz time domain multiplex (TDM) MIMO radar is presented. The sensor is feasible for advanced direction of arrival (DOA) estimation in azimuth and elevation. For efficient and high-quality measurements a fractional-n phased locked loop (PLL) with integrated waveform generator, enabling chirp and frequency modulated continous waveform (FMCW) modulations, is implemented. Spatial beamforming is done with series feed array patch antennas in combination with a dielectric cylindrical lens. For the improvement of the direction of arrival (DOA) estimation performance a new lens-based MIMO radar approach is introduced. Therefore the classical MIMO approach is combined with the advantages of an optical beamforming concept. Due to the usage of these techniques the sensor performance in accuracy, ambiguity suppression, and angular resolution can be significantly increased.
elib2cris::1512001600,lutz2014
Keywords: Radar applications; Radar architecture and systems

Let's Make Them Cognitive! Cognitive Radio Technology Applied to Professional Wireless Microphone Systems - Kloc, Matej; Rieß, Steffen; Brendel, Johannes; Linz, Sarah; Gardill, Markus; Weigel, Robert; Fischer, Georg (IEEE Microwave Magazine, 2016)
elib2cris::1512001600,kloc2016

Leveraging Real-World Data for the Selection of Relevant Eligibility Criteria for the Implementation of Electronic Recruitment Support in Clinical Trials - Melzer, Georg; Maiwald, Tim; Prokosch, Hans-Ulrich; Ganslandt, Thomas (Applied Clinical Informatics, 2021)
Background Even though clinical trials are indispensable for medical research, they are frequently impaired by delayed or incomplete patient recruitment, resulting in cost overruns or aborted studies. Study protocols based on real-world data with precisely expressed eligibility criteria and realistic cohort estimations are crucial for successful study execution. The increasing availability of routine clinical data in electronic health records (EHRs) provides the opportunity to also support patient recruitment during the prescreening phase. While solutions for electronic recruitment support have been published, to our knowledge, no method for the prioritization of eligibility criteria in this context has been explored. Methods In the context of the Electronic Health Records for Clinical Research (EHR4CR) project, we examined the eligibility criteria of the KATHERINE trial. Criteria were extracted from the study protocol, deduplicated, and decomposed. A paper chart review and data warehouse query were executed to retrieve clinical data for the resulting set of simplified criteria separately from both sources. Criteria were scored according to disease specificity, data availability, and discriminatory power based on their content and the clinical dataset. Results The study protocol contained 35 eligibility criteria, which after simplification yielded 70 atomic criteria. For a cohort of 106 patients with breast cancer and neoadjuvant treatment, 47.9% of data elements were captured through paper chart review, with the data warehouse query yielding 26.9% of data elements. Score application resulted in a prioritized subset of 17 criteria, which yielded a sensitivity of 1.00 and specificity 0.57 on EHR data (paper charts, 1.00 and 0.80) compared with actual recruitment in the trial. Conclusion It is possible to prioritize clinical trial eligibility criteria based on real-world data to optimize prescreening of patients on a selected subset of relevant and available criteria and reduce implementation efforts for recruitment support. The performance could be further improved by increasing EHR data coverage.
CRIS-Team Scopus Importer:2021-01-29
Keywords: clinical trial; data warehousing and data marts; electronic health records and systems; recruitment; secondary use

Lichtmessung in der Stallumgebung - Müller, Maike; Reiter, Klaus; Werner, Daniel; Schneider, Michael; Schwenzfeier-Hellkamp, Eva (DLG Fachausschuss Technik in der tierischen Produktion, 2015)

Lichtmessung in der Stallumgebung - Werner, Daniel; Schneider, Michael; Schwenzfeier-Hellkamp, Eva; Müller, Maike; Reiter, Klaus (DLG Fachausschuss für Tiergerechtheit, 2015)

Linear and efficient Doherty PA Revisited - Musolff, Christian; Kamper, Michael; Abou-Chahine, Zeid; Fischer, Georg (IEEE Microwave Magazine, 2014)
elib2cris::1512001600,musolff2014
Keywords: power amplifier; doherty; linear; 3.5GHz; IMD; RFPA; PA; student design competition

Linear Doherty PA at 5 GHz - Musolff, Christian; Kamper, Michael; Fischer, Georg (IEEE Microwave Magazine, 2015)

Linear Frequency Ramp Generation for Local Positioning - Eickhoff, Ralf; Ellinger, Frank; Ußmüller, Thomas; Hüttner, Jörg; Gierlich, Roland (Semiconductor Conference Dresden, 2008)
elib2cris::1512001600,eickhoff2008a

Linearity Analysis of High-Voltage RF Switches for Antenna Tuning Applications - Özdamar, Oguzhan; Weigel, Robert; Solomko, Valentyn; Hagelauer, Amelie (IEEE Transactions on Microwave Theory and Techniques, 2021)
An analysis describing nonlinearities in shunt aperture tuning radio frequency (RF) switches operating in off-state is presented in this article. The focus is put on the analysis of second- and third-order nonlinear products and their power distribution as a function of geometry of high-voltage (HV) field-effect-transistor (FET)-based RF switch. According to the results of analysis, the third-order nonlinear product can be reduced by 6 dB at the expense of 4.1 dB increase in the second-order product by doubling the stack size and transistor width used in the switch. The analytical findings are verified with measurements for which two integrated circuits (ICs) were designed and manufactured in Infineon 130-nm RF switch technology. The experiment demonstrated reasonable hardware-to-model correlation, showing around +8 and -7 dB difference in second and third harmonic and intermodulation (IM) products between high-voltage (HV) and low-voltage (LV) RF switches, respectively.
CRIS-Team Scopus Importer:2021-08-20
Keywords: Antenna tuning; aperture tuning; Capacitance; CMOS switch; Harmonic analysis; harmonics; high-voltage (HV) radio frequency (RF) switch; intermodulation (IM); MOSFET; nonlinearity; Predictive models; Radio frequency; RF front-end.; Substrates; Transistors

Linearity Considerations of W-CDMA Front-Ends for UMTS - Pretl, Harald; Maurer, Linus; Schelmbauer, Werner; Weigel, Robert; Adler, Bernd; Fenk, Josef (IEEE MTT-S Microwave Symposium, 2000)
elib2cris::1512001600,pretl2000

Linearity Trade-offs in High-Voltage RF Switches for Antenna Tuning Applications - Özdamar, Oguzhan; Weigel, Robert; Solomko, Valentyn; Hagelauer, Amelie (Asia-Pacific Microwave Conference Proceedings, APMC, 2020)
An analysis describing the harmonics distribution in a shunt aperture tuning RF switch operating in OFF mode is presented in the paper. The focus is put on the second and third harmonic power distribution as a function of geometry of an RF switch. The analytical findings are verified with measurements for which the two integrated circuits were manufactured in Infineon 130 nm RF switch technology. Both the analytical model and the measurements show, that there is a trade-off between the second and third harmonic depending on the geometry of the RF switch.
Created from Fastlane, Scopus look-up
Keywords: antenna tuning; aperture tuning; harmonics; high-voltage RF switch; IC design; nonlinearity

Linearization of Power Amplifiers by Means of Digital Predistortion - Ceylan, Nazim (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2005)

Linearizing the Output Characteristics of GMR Current Sensors through Hysteresis Modeling - Jedlicska, Istvan; Weiß, Roland; Weigel, Robert (IEEE Transactions on Industrial Electronics, 2010)
elib2cris::1512001600,jedlicska2010

Load modulated massive MIMO - Müller, Ralf; Sedaghat, Mohammad Ali; Fischer, Georg (2014 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2014, 2014)
We propose a new hardware architecture for cost-and size-effective implementation of massive MIMO transmitters based on load modulation that is fully compatible with standard receiver architectures. With load modulation, a massive MIMO transmitter can be driven by a single power amplifier operating at constant envelope. The various data streams are modulated onto the antennas elements by varying the complex impedances of the various antenna circuits at symbol rate. The law of large numbers ensures that the common power source is matched to the parallel concatenation of the various antenna circuits, if the number of antenna elements is very large. For 100 antenna elements that are supposed to transmit Gaussian-like signals, e.g. due to OFDM modulation and/or precoding, the crest factor is only 1.2 dB at a clipping probability of 0.1%. In that case, load modulation reduces the average consumed power and the amplifier peak power by 49% and 79%, respectively, as compared to classical distributed amplifiers with voltage modulation. Furthermore, one class F amplifier can be used to replace 100 class A/B amplifiers. Mutual antenna coupling need not be addressed by a physical matching network, but can be mitigated dynamically by digital signal processing in baseband without additional hardware. This allows for closer antenna spacing as in architectures with distributed amplifiers.
Keywords: Antenna coupling; Crest factor; Load modulation; Massive MIMO; Multi-antenna systems; Power amplifier

Localization for Search and Rescue Applications - Zorn, Stefan (Radio and Wireless Symposium, 2009)
elib2cris::1512001600,zorn2009

Localization of Passively Guided Capsule Endoscopes-A Review - Zeising, Samuel; Thalmayer, Angelika; Lübke, Maximilian; Fischer, Georg; Kirchner, Jens (IEEE Sensors Journal, 2022)

Local Positioning for Wireless Sensor Networks - Ellinger, Frank; Eickhoff, Ralf; Gierlich, Roland; Hüttner, Jörg; Ziroff, Andreas; Wehrli, Silvan; Ußmüller, Thomas; Carls, Jörg; Subramanian, Viswanathan; Krcmar, Marko; Mosshammer, Ralf; Spiegel, Solon; et al. (Globecom Workshops, 2007 IEEE, 2007)
This workshop paper gives an overview of local positioning and tracking principles for wireless sensor networks including recent results of the European project RESOLUTION (reconfigurable systems for mobile local communication and positioning). Measurements of a first demonstrator applying a frequency modulated continuous wave (FMCW) radar principle are presented. The unlicensed ISM band around 5.8 GHz, 150 MHz bandwidth and less than 25 mW effective isotropic radiated transmit power are used. Excellent 3-D positioning accuracies in the order of 4 cm in an anechoic chamber and 18 cm in a conference hall with strong multipath and area of 800 m2 are measured. Furthermore, the results of optimized radio frequency integrated circuits and a suitable compact flash card are outlined.
elib2cris::1512001600,ellinger2007a
Keywords: BiCMOS; FMCW; integrated circuits; local positioning; radar; radio frequencies; tracking; wireless sensors; Anechoic chambers; Area measurement; Bandwidth; Frequency measurement; Frequency modulation; Mobile communication; Position measurement

Local Positioning mit einem integrierten Breitband-FMCW System - Maser, Matthias; Gardill, Markus; Gulden, Peter; Fischer, Georg; Weigel, Robert; Ußmüller, Thomas (Electrical and Electronic Engineering for Communication, EEEfCOM 2012, 2012)
elib2cris::1512001600,maser2012a
Keywords: Local Positioning

Local Positioning With Passive UHF RFID Transponders - Heidrich, Jürgen; Brenk, Daniel; Essel, Jochen; Fischer, Georg; Weigel, Robert; Schwarzer, Stefan (IEEE MTT-S International Microwave Workshop on Wireless Sensing, Local Positioning, and RFID, 2009)
This paper describes the theory of distance measurements with passive UHF transponders using the principle of modulated backscattering. The method was evaluated with the analogue frontend of a passive RFID chip for the UHF range. The chip was designed in a 0.14mum CMOS technology.
elib2cris::1512001600,heidrich2009
Keywords: CMOS technology; chip design; distance measurement; local positioning; modulated backscattering; passive UHF RFID transponder; size 0.14 mum; CMOS integrated circuits; UHF devices; backscatter; distance measurement; microprocessor chips; radiofrequency identification; transponders

Local positioning with sensor-enabled passive multistandard RFID transponders - Heidrich, Jürgen; Brenk, Daniel; Essel, Jochen; Schwarzer, Stefan; Herschmann, R.; Geck, Bernd; Fischer, Georg; Weigel, Robert (Advances in Radio Science : Kleinheubacher Berichte, 2010)
RFID is used today in many fields of every day life like access control, anti-theft protection or logistics. Within this article a short overview of the basic RFID principles and the EPC protocol flow is given at first. Afterwards new design approaches for RFID systems within the scope of the research project RFID-S are presented.
elib2cris::1512001600,heidrich2010

Local Pulse Wave Detection using Continuous Wave Radar Systems - Will, Christoph; Shi, Kilin; Schellenberger, Sven; Steigleder, Tobias; Michler, Fabian; Weigel, Robert; Ostgathe, Christoph; Kölpin, Alexander (IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology, 2017)

Locatable Sensor-Enabled Multistandard RFID tags - Brenk, Daniel; Essel, Jochen; Heidrich, Jürgen; Weigel, Robert (Springer-Verlag, 2009)
elib2cris::1512001600,brenk2009

Lokalisierung in Sensornetzwerken und deren Basisbandverarbeitung - Jung, Melanie; Ferizi, Alban; Weigel, Robert (HF-Praxis, 2011)
Die Vielfalt der Lokalisierung- und Ortungssysteme stieg in den vergangenen Jahren rasant an. Neben den bekannten Ortungsverfahren über Galileo und GPS im privaten und industriellen Einsatz gewinnt die Lokalisierung innerhalb von Gebäuden immer mehr an Bedeutung. Hierbei sind besonders die meist auf FMCW (Frequency Modulated Continuous Wave) basierenden Sensornetzwerke hervorzuheben, die eine Vielzahl an Einsatzmöglichkeiten erlauben. Die Verbesserung von Produktionsabläufen durch Positionsbestimmung von Waren, Produktionsmitteln oder Maschinen ist ein mögliches Einsatzgebiet, aber auch die verbesserte Orientierung von Feuerwehr oder anderen Einsatzkräften in Gebäuden ist denkbar. Im Gegensatz zu satellitengestützten Ortungssystemen entstehen bei lokalen Systemen innerhalb von Gebäuden mehr Reflektionen des Signals an Oberflächen. Um die damit verbundene Mehrwegeausbreitung bestmöglich zu handhaben, bestehen hohe Anforderungen an das System und die Signalverarbeitung im Basisband. In diesem Beitrag wird die CMOS Signalverarbeitung im Basisband für einen Sensorknoten mit Lokalisierung näher beleuchtet. Diese wird im Gegensatz zu anderen Ansätzen vollständig in CMOS auf einem Chip realisiert, um so Platz- und Energiebedarf zu reduzieren. Auf diese Weise werden die Massenfabrikation und der großflächige Einsatz erleichtert.
elib2cris::1512001600,jung2011

Low complex IQ-imbalance compensation for low-IF receivers - Hüttner, Jörg; Reinhardt, Steffen; Huemer, Mario (IEEE Radio and Wireless Symposium, 2006, 2006)
The evolution of wireless communication systems forces the development of cheaper and smaller analog components for the RF (radio frequency)-frontend. To an increasing degree digital algorithms are used to compensate analog nonidealities, lowering the requirements for the analog frontend. Consequently, simpler, cheaper and smaller analog frontends can be applied without loosing overall system performance. The most critical frontend-nonidealities, whose dimensions are dependent on the chosen transceiver concept, are amplifier-nonlinearities, phase noise, DC-offset, 1/f-noise, carrier frequency offset and IQ-mismatch. In recent years homodyne and low-IF (intermediate frequency) architectures supersede the conventional heterodyne concepts. In this paper we will present IQ-imbalance compensation techniques for low-IF transceiver architectures and we will present a very low-complex digital compensator, which operates with only four complex multiplications per sample.
elib2cris::1512001600,huettner2006
Keywords: Baseband; Digital signal processing; Filters; Mirrors; RF signals; Radio frequency; Receivers; Signal processing; Signal processing algorithms; Tiles

Low Complexity 60-GHz Receiver Architecture for Simultaneous Phase and Amplitude Regenerative Sampling Systems - Girg, Thomas; Schrüfer, Daniel; Dietz, Marco; Hagelauer, Amelie Marietta; Kissinger, Dietmar; Weigel, Robert (International Symposium on Integrated Circuits, 2016)
With increasing data rates in communication systems, the call for wideband transceiver solutions capable of processing complex modulation schemes is getting stronger. Unfortunately, this goes along with power hungry systems and more complex integrated circuits. A novel receiver architecture, which addresses these issues, is based on the simultaneous phase and amplitude regenerative sampling system. Its system exploits switched injection-locked oscillators and their capability to regenerate signals with a gain of over 40dB. This paper demonstrates an integrated solution for phase demodulation in such an architecture. The proposed concept uses the low complex but efficient self-mixing principle and consists mainly of double-balanced Gilbert mixers, amplifiers, a delay line and passive power dividers. The detection of the phase is achieved through self-mixing the regenerated signal with one path delayed by a symbol period. The architecture achieves 2 GBaud/s with 8 th order differential phase shift keying at a frequency of 60 GHz and is realized in a 130nm SiGe BiCMOS technology.
elib2cris::1512001600,girg2016a
Keywords: SiGe; BiCMOS; simultaneous phase and amplitude regenrative sampling; high data rate; communication; self-mixing

Low complexity turbo-like decision feedback equalization for broadband wireless single carrier systems - Koopler, A.; Springer, Andreas; Huemer, Mario; Weigel, Robert (Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, 2003)
Single carrier transmission with frequency domain equalization (SC/FDE) provides a serious alternative to orthogonal frequency division multiplexing (OFDM) for broadband wireless access (BWA) systems as well as for W-LAN's. In this work we consider low complexity Turbo-like decision feedback equalization for conventional block wise SC/FDE. The proposed scheme accomplishes the efficiency of ideal decision feedback equalization. Simulation results show a remarkable performance increase for large signal constellations and highly frequency selective multipath channels.
elib2cris::1512001600,koopler2003
Keywords: OFDM; WLAN; broadband wireless access; broadband wireless single carrier systems; frequency domain equalization; frequency selective multipath channels; low complexity turbo-like decision feedback equalization; orthogonal frequency division multiplexing; signal constellations; single carrier transmission; wireless local area network; OFDM modulation; broadband networks; decision feedback equalisers; frequency-domain analysis; multipath channels; optimisation; wireless LAN

Low-Cost and High Performance Antenna Setup for Updating ePaper Displays on Curved RFID SmartTags Used in Pharmaceutical Studies - Peters, Sebastian; Hangmann, Christian; Wüllner, Ingo; Traupe, Joschka; John, Tobias; Weigel, Robert; Scheiner, Benedict (IEEE MTT-S International Microwave Symposium Digest, 2023)
This work presents a scalable RFID antenna setup used to update passive SmartTags mounted on round containers. Examples where this technology can be highly beneficial are pharmaceutical studies. The reader antennas are placed under the containers and are designed to ensure RFID communication and power transfer independent of container rotation with multiple containers in close proximity. The effects of the proposed antenna setup on the system are analyzed both theoretically and in simulations. Measurements are performed to verify the results and to demonstrate the system.
CRIS-Team Scopus Importer:2023-09-01
Keywords: antenna arrays; HF antennas; medical information systems; RFID tags; smart healthcare; smart transportation

Low-Cost Direction-of-Arrival Measurements using Multiplexed Antenna Switching - Dorn, Christian; Erhardt, Stefan; Weigel, Robert; Kölpin, Alexander; Lurz, Fabian (Wireless Sensors and Sensor Networks, 2020)

Low-Cost Six-Port for High-Volume Frequency Measurement Systems in the 2.4 GHz ISM-Band - Scheiner, Benedict; Probst, Florian; Michler, Fabian; Weigel, Robert; Kölpin, Alexander; Lurz, Fabian (IEEE Topical Conference on Wireless Sensors and Sensor Networks 2021, 2021)

Low-cost Software-Defined Radio System with Deterministic RX to TX Delay Using Timestamps - Dorn, Christian; Depold, Andreas; Lurz, Fabian; Hagelauer, Amelie (2023 IEEE Topical Conference on Wireless Sensors and Sensor Networks, WiSNeT 2023, 2023)
Systems that rely on high-level software share the same disadvantage. Their execution time is unknown and thus the result of the processing is not available after a deterministic delay. The same is valid for software-defined radios. When only in receive (RX) mode the impact of the varying delay is negligible most of the time. However, in the case that the SDR needs to transmit (TX) this delay prevents from synchronizing the TX to the RX. This is crucial for many applications in communication and sensing though. This publication proposes and implements a method on a low-cost SDR transceiver, that provides the possibility to TX at a given time related to the RX with an error of ±l sample.
CRIS-Team Scopus Importer:2023-03-17
Keywords: software-defined radio (SDR); time synchronization

Low-cost Transmitarray Antenna Designs in V-Band based on Unit-Cells with 1 Bit Phase Resolution - Frank, Martin; Scheiner, Benedict; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (Frequenz, 2019)

Low-cost Transmitarray Antenna Designs with +/-70° Beam Steering Range in V-Band - Frank, Martin; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (2019 12th German Microwave Conference (GeMiC), 2019)

Low-Frequency Magnetic Localization of Capsule Endoscopes with an Integrated Coil - Zeising, Samuel; Seidl, Rebecca; Thalmayer, Angelika; Fischer, Georg; Kirchner, Jens (8th International Symposium on Sensor Science, 2021)

Low Impedance Multi-Decade Integrated Amplifier for EMR Measurements in Fully Electric Vehicles - Chicharro, José Antonio; Weigel, Robert; Fischer, Georg; Ußmüller, Thomas (Asia-Pacific International Symposium and Exhibition on Electromagnetic Compatibility, 2013)
This paper reports on the design, simulation and measurement of a low-impedance broadband integrated amplifier in bipolar technology (Infineon’s B7HF200). Aimed to serve as a LNA for an inductive field probe operating in the frequency range 5 kHz - 6 GHz, the amplifier is designed to offer a good performance with a purely resistive 10-Ohm power source. A nominal gain of 30 dB up to 1 GHz (15 dB at 6 GHz) and and input scattering parameter s11 of -10 decibels are achieved. Power consumption is 30 mW. Limitations of and improvements for this design are discussed.
elib2cris::1512001600,chicharro2013
Keywords: Bipolar; Integrated circuits; broadband amplifier; low-impedance LNA; EMR measurements; multi-decade

Low Impedance Wheel Resonators for Low Voltage and Low Power Applications - Nawaz, Mohsin (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2009)

Low Latency Evaluation of an Adaptive Industrial Wireless Communications System for ISM Bands - Kloc, Matej; Franchi, Norman; Gardill, Markus; Weigel, Robert (IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2016)
Low latency and highest transmission reliability are the key challenges for enabling time-critical industrial wireless applications, e.g. in factory automation. Both are significantly determined by the rough and dynamic environmental conditions as well as regulatory limitation of spectrum access in unlicensed frequency bands, especially in the 2.4 GHz industrial, scientific and medical (ISM) band. In order to get these influences under control, a novel concept for an adaptive and low latency (≤ 1 ms) industrial wireless communications (IWC) system that adopts a robust IEEE 802.11p physical layer (PHY) is proposed and evaluated. Based on representative coexistence measurements in a real environment, the results of extensive simulations and analysis are shown in order to evaluate achievable latencies.
elib2cris::1512001600,kloc2016a

Low-Loss BAW Filters on High Resistivity Silicon for Mobile Radio - Hagelauer, Amelie Marietta; Bader, Bernhard; Henn, G.; Schaeufele, A.; Marksteiner, Stefan; Wagner, Karl Christian; Weigel, Robert (International Microwave Symposium, 2009)
Integration of bulk acoustic wave (BAW) filters into W-CDMA mobile communication applications is of high interest, as the BAW technology allows for low-loss and high Q signal forming in these 2 GHz devices. During the design phase of low- loss BAW filters it is very important that we not only control the most major loss mechanisms, like metal conductivity and viscosity of piezo material. We also have to focus the less well known losses. In this paper, we describe an interface loss effect which appears between the Si substrate and the first SiO2 layer of the BAW structure. Its influence on the filter characteristics of our 2 GHz filter is shown. This loss effect is caused by channel currents, which are induced by static charges (similar in FET transistors). For investigating the loss and its impact on the filter performance, we designed test structures and filters, performed and analyzed measurements, and adapted the loss model in our filter simulations accordingly.
elib2cris::1512001600,hagelauer2009
Keywords: FET transistors; SiO2; W-CDMA mobile communication applications; acoustic resonator filters; bulk acoustic wave filters; channel currents; low-loss BAW filters; metal conductivity; mobile radio; piezo material; static charges; acoustic resonator filters; bulk acoustic wave devices; code division multiple access; mobile radio; silicon compounds

Low-Loss Broadband SAW Two-Track Reflector Filter using Chirped Structures for Mobile Radio Applications - Weigel, Robert; Nalezinski, Martin; Valenzuela, Alejandro; Russer, Peter (Proc. Asia-Pacific Microwave Conference, 1993)
elib2cris::1512001600,weigel1993d

Low Noise Phase Locked VCO at 2.5 GHz for Optical Transmission Networks using Fifth Harmonic STW Delay Line - Fleischmann, Bernd; Roth, Alexander; Russer, Peter; Weigel, Robert (20th European Microwave Conference, 1990, 1990)
A hybrid VCO at 2488.32 MHz, which is phase locked to a crystal oscillator operating at 75.4 MHz, is described. As the frequency controlling element of the VCO, acoustic surface transverse wave (STW) delay lines operating at the fifth harmonic are used. In order to reduce the delay line electromagnetic feedthrough, a three-transducer type STW filter design is combined with a microstrip rat-race coupler. The filters were designed using advanced analysis methods and fabricated on rotated Y-cut quartz substrates with a standard photolithographic process. The delay lines were characterized by a center frequency of 2.49 GHz, an untuned insertion loss of 22 dB, an unloaded Q value of 1280, and a group delay time of 158 ns. The signal of the VCO is mixed with the local (crystal) oscillator signal multiplied by 32, thus providing an IF-signal of 75.4 MHz feeding the phase locked loop which has a bandwidth of 300 kHz. A single-sideband phase noise to carrier ratio of Â¿112 dBc/Hz at 1 kHz offset has been attained. The present work arose from a requirement for a low noise frequency source for direct generation of the SONET (Synchronous Optical Network) bit frequency of 2488.32 MHz.
93781a41-0f22-4bbe-83c8-b30fb0ad65d3::1512001600,fleischmann1990
Keywords: Delay lines; Electromagnetic coupling; Frequency; Optical fiber networks; Optical noise; Phase noise; Power harmonic filters; SONET; Surface acoustic waves; Voltage-controlled oscillators

Low-Noise Surface Transcerse Wave Oscillators - Weigel, Robert; Russer, Peter (Proc. MIOP'90-Kongressmesse fuer Hoechstfrequenztechnologie, 1990)
93781a41-0f22-4bbe-83c8-b30fb0ad65d3::1512001600,weigel1990

Low Phase Noise Frequency-Synthesizer with Very High Frequency-Resolution for GSM 900/DCS 1800 - Neurauter, Burkhard; Märzinger, Günther; Lüftner, Thomas; Weigel, Robert; Scholz, Markus; Mutlu, Varol; Fenk, Josef (30th European Microwave Conference, 2000)
This paper presents a fractional-n frequency synthesizer that uses AC-modulation to obtain the desired fractional division value. After a brief presentation of the synthesizers' key elements a detailed noise analysis follows. Measurements from the prototype synthesizer validate the very good phase noise performance which is predicted by theory. The realized high frequency resolution can be used to compensate the frequency error of the reference crystal oscillator in a typical GSM transceiver.
elib2cris::1512001600,neurauter2000
Keywords: 1f noise; Distributed control; Frequency synthesizers; GSM; Noise measurement; Oscillators; Phase measurement; Transceivers; Phase noise; Prototypes

Low Power 24 GHz ad hoc Networking System Based on TDOA for Indoor Localization - Jung, Melanie; Fischer, Georg; Weigel, Robert; Ußmüller, Thomas (ISPRS International Journal of Geo-Information, 2013)
This paper introduces the key elements of a novel low-power, high precision localization system based on Time-Difference-of-Arrival (TDOA) distance measurements. The combination of multiple localizable sensor nodes, leads to an ad hoc network. Besides the localization functionality this ad hoc network has the additional advantage of a communication interface. Due to this a flexible positioning of the master station for information collection and the detection of static and mobile nodes is possible. These sensor nodes work in the 24 GHz ISM (Industrial Scientific and Medical) frequency range and address several use cases and are able to improve various processes for production scheduling, logistics, quality management, medical applications and collection of geo information. The whole system design is explained briefly. Its core component is the frequency modulated continuous wave (FMCW) synthesizer suitable for high performance indoor localization. This research work focuses on power and size reduction of this crucial system component. The comparison of the first and second generation of the system shows a significant size and power reduction as well as an increased precision.
elib2cris::1512001600,jung2013
Keywords: fmcw; tdoa; ad hoc networking; pll; synthesizer; tspc; frequency divider

Low-Power Analog Smart Camera Sensor for Edge Detection - Söll, Christopher; Shi, Lan; Röber, Jürgen; Reichenbach, Marc; Weigel, Robert; Hagelauer, Amelie Marietta (IEEE International Conference on Image Processing (ICIP), 2016)
This work presents an intelligent analog image sensor system for smart camera applications with the need of edge or marker detection. The system consists of a 3x3 read-out CMOS image sensor, an analog Sobel stage and additional circuitry like operational amplifiers and comparators to compute a 1bit image with the edges present in the taken photo. This information can then be further processed digitally to detect specific shapes in order to control robot routines, for example. The architecture of the proposed system is highly desirable as dedicated analog hardware has significant advantages in terms of power and speed compared to digital implementations. The overall system is simulated with the help of a 3x3 CMOS image sensor IC as well as Cadence Virtuoso for analog circuit simulation and MATLAB to convert the sequential information back to an image, and compared to other state of the art CMOS image sensors with edge detection capability. The analog Sobel circuit runs with a clock of 10MHz and consumes less than 0.79mW average power for the computation of the example image, and the whole 200x200 pixel image sensor consumes only 5.5mW at a frame rate of 75 fps.
elib2cris::1512001600,soell2016
Keywords: Smart Camera; CMOS Image Sensor; Analog Processing Circuits; Analog Sobel; GRK-1773

Low-power contactless LC-tank based respiratory sensor - Scheiner, Benedict; Schellenberger, Sven; Shi, Kilin; Heusinger, Elisabeth; Michler, Fabian; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (Electronics Letters, 2019)

Low-Power Frequency Synthesizer for Multi-Tone Six-Port Radar - Lurz, Fabian; Hofstetter, Patrick; Lindner, Stefan; Linz, Sarah; Michler, Fabian; Weigel, Robert; Kölpin, Alexander (IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2018)

Low-Power Galileo/GPS Single-Shot Receiver Architecture for Mobile Terminals - Kandziora, Christoph (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2014)

Low-Power High-Gain Operational Amplifier for Analog Image Pre-Processing in Smart Sensor Systems - Söll, Christopher; Mai, Timo; Shi, Lan; Röber, Jürgen; Ußmüller, Thomas; Weigel, Robert; Hagelauer, Amelie Marietta (15. ITG/GMM-Fachtagung Analog 2016, 2016)
In this work, a low-power high-gain operational amplifier is presented, which is dedicated to work in an analog image pre-processing stage in a smart sensor system. This stage is able to detect edges and shapes for instance, before the image is passed to the ADC and the digital computation stage, reducing data and precision requirement of both stages. This approach helps to save power, making smart image sensor nodes with energy harvesting reasonable. Since the precision as well as the energy consumption of the edge detection algorithm is highly depended on the amplifier used for the basic summing and multiplier blocks, the design of it plays an important role for the approach. The proposed input/output rail-to-rail operational amplifier is based on a 150 nm CMOS process, has a gain of 77 dB and a unity gain bandwidth of 45.7MHz while consuming only 77 μA statically at a supply voltage of 1.8V.
elib2cris::1512001600,soell2016c
Keywords: analog pre-processing; operational amplifier; low-power; high-gain; folded-cascode; GRK-1773

Low-Power K-Band LNA in 45 nm SOI CMOS - Issakov, Vadim; Ciocoveanu, Radu (2019 IEEE INTERNATIONAL CONFERENCE ON MICROWAVES, ANTENNAS, COMMUNICATIONS AND ELECTRONIC SYSTEMS (COMCAS), 2019)
CRIS-Team WoS Importer:2020-07-10

Low Power RF-Synthesizer Design for a 3rd Generation WCDMA Transceiver using Deep Submicron CMOS Technology - Konstanznig, Georg; Weigel, Robert (Workshop Analogschaltungen, 2004)
elib2cris::1512001600,konstanznig2004

Low-profile and low-cost Transmitarray Antenna at 122 GHz based on Unit-Cells with 1-bit Phase Resolution - Frank, Martin; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (Electronics Letters, 2020)

Low TB radio SAW sensors incorporating chirped transducers and reflectors for wireless pressure sensing applications - Pankratz, Thomas; Scherr, Holger; Reindl, Leonhard; Ruppel, Clemens; Weigel, Robert (1998 IEEE MTT-S International Microwave Symposium Digest, 1998)
We report on the design and performance of two basic SAW delay line structures developed for a wireless pressure sensing system operating at 434 MHz. The pressure sensor has been fabricated in all-quartz-package (AQP) technology with the SAW structures being placed on a diaphragm inside the hermetically sealed cavity. Both SAW structures show a linear phase although they both incorporate chirped SAW components for enhancing the sensor sensitivity. They have low time-bandwidth (TB) products of 2 and 11, respectively. We attained an improvement of the sensor sensitivity by factors of up to 20 compared to sensors employing non-dispersive SAW components.
elib2cris::1512001600,pankratz1998

Low Voltage Reference Cells for UHF Transponders with Advanced Features - Heidrich, Jürgen; Brenk, Daniel; Essel, Jochen; Hofer, Günter; Holweg, Gerald; Fischer, Georg; Weigel, Robert (IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems, 2009)
In this paper a low voltage RC oscillator for standard RFID applications and local positioning is presented. Its bias current is provided by a current-mode bandgap whose reference voltage can also be used for enhanced transponder applications like sensing. The chip is designed in a 0.13 Â¿m CMOS technology with p substrate. It was developed at the Institute for Electronics Engineering within the scope of a research project supported by the Bavarian Research Foundation.
elib2cris::1512001600,heidrich2009a
Keywords: CMOS technology; RFID applications; UHF transponders; CMOS integrated circuits

Low Weight Non-Invasive Heart Beat Detector for Small Airborne Vertebrates - Duda, Niklas; Ripperger, Simon; Mayer, Frieder; Weigel, Robert; Kölpin, Alexander (IEEE Sensors Letters, 2020)

Low-Weight Wireless Sensor Network for Encounter Detection of Bats - Hierold, Martin; Ripperger, Simon; Josic, Darija; Mayer, Frieder; Weigel, Robert; Kölpin, Alexander (IEEE Topical Meeting on Wireless Sensors and Sensor Networks, 2015)
In this paper a compact low weight wireless sensor node for proximity detection is presented. The energyefficient system design enables an operation time of more than 9 days at a total weight of the tag of less than 2 g. Test measurements in a colony of bats proof the applicability of the system for encounter detection of individual bats based on received signal strength measurements.
elib2cris::1512001600,hierold2015
Keywords: energy efficiency; wireless sensor network

Low-weight Wireless Sensor Node for Animal Encounter Detection and Dual-band Localization - Hierold, Martin; Hartmann, Markus; Ripperger, Simon; Mayer, Frieder; Heuberger, Albert; Weigel, Robert; Kölpin, Alexander (IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2016)

Low Weight Wireless Sensor Node With Sensor-Data Enhanced Dual Frequency RSSI Based Distance Estimation - Duda, Niklas; Weigel, Robert; Kölpin, Alexander (IEEE Transactions on Microwave Theory and Techniques, 2020)

LP Decoding of LDPC Codes in HARQ Systems - Lunglmayr, Michael; Berkmann, Jens; Huemer, Mario (6th Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP’08), 2008)
The combination of low density parity check (LDPC) Codes and Automatic Repeat reQuest (ARQ) has shown to be a promising option to increase the throughput of a communication system. A recently proposed method uses the decoding result to request unreliable bits for retransmission (reliability-based Hybrid ARQ). Commonly, Belief Propagation is used to decode LDPC codes. The result of this algorithm naturally provides an estimate for the probability of a bit to be erroneous. Another possibility to decode LDPC codes is via linear programming (LP) decoding. Despite some drawbacks (e.g. in terms of implementation complexity), linear programming decoding provides an interesting alternative to Belief Propagation. This work investigates the feasibility of combining LP decoding with ARQ. In lack of a probability measure for the decoded bits, when using LP decoding, request criteria using the integrality of the values in the LP solution are proposed. We present statistical investigations on the proposed criteria and the results of throughput simulations demonstrating the gains achievable by the proposed methods.
elib2cris::1512001600,lunglmayr2008b

LSAW attenuation in double-layer-systems - Wallner, Paul; Ruile, Werner; Weigel, Robert (IEEE International Frequency Control Symposium, 1999)
The behavior of Leaky-SAW (LSAW) in layered structures was investigated by new computer calculations. For these investigations rotYX LiTaO3 and rotYX LiNbO3 crystal cuts were used. Surface acoustic wave propagation is strongly influenced by thickness, density, and elasticity of the layers. For LSAW both the velocity and the inherent loss due to bulk wave emission into the substrate depend on these layer properties. Double-layer-systems can be taken into account if Si3N4 or Al2O3 is added on the metal layer. As a result, this double-layer-system shows new properties: the angle of minimum propagation loss and the velocity strongly depend on distinct parameters and ratios of the layers. This means that in double-layer-systems the behavior of LSAW loss and velocity differs from single-layer-structures
elib2cris::1512001600,wallner1999a

Machine Learning using Neural Networks in Digital Signal Processing for RF Transceivers - Jüschke, Patrick; Fischer, Georg (IEEE Africon, 2017)

Magnetic Steering of Superparamagnetic Nanoparticles in Duct Flow for Molecular Communication: A Feasibility Study - Schlechtweg, Niklas; Meyer, Sebastian; Unterweger, Harald; Bartunik, Max; Ahmed, Doaa; Wicke, Wayan; Jamali, Vahid; Alexiou, Christoph; Fischer, Georg; Weigel, Robert; Schober, Robert; Kirchner, Jens (Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST, 2019)
Molecular communication (MC) denotes information transmission by use of molecules and nanosized particles. For the realization of testbeds, superparamagnetic iron oxide nanoparticles (SPIONs) in duct flow have recently been proposed. Here, an experimental setup is provided to direct these particles at a branching of a tube into a specific direction by use of magnetic fields. For that purpose, gold-coated SPIONs suspended in water at constant flow rate are considered at a Y-shaped connector of tubes. The particles are attracted by use of a custom-made electromagnet, while change of particle concentration in either of the branches is measured by a commercial susceptometer. The approach is evaluated for different flow rates and with the electromagnet both at a fixed position and moving along the tube. Exemplary measurements show that an information transmission is feasible in both approaches and with all tested flow rates. The feasibility study hence shows that particle steering by use of magnetic fields is a viable approach, which is even robust against flow rate variations. It can thus be used in MC to address different transmission channels as well as to realize differential signal transmission. Furthermore, it might help to improve magnetic drug targeting in future applications.
CRIS-Team Scopus Importer:2019-12-27
Keywords: Duct flow; Magnetic field; Molecular communication; Particle steering; Superparamagnetic nanoparticles

Making Real-Time Hardware-in-the-Loop Testing of Automotive Electronic Control Units Wireless - Kloc, Matej; Weigel, Robert; Kölpin, Alexander (Advanced Technologies for Communications (ATC), 2016)
elib2cris::1512001600,kloc2016b

Markovian channel modeling for multipath mitigation in navigation receivers - Krach, Bernhard; Weigel, Robert (European Conference on Antennas and Propagation, 2009)
Multipath is today still one of the most crucial problems in satellite navigation, in particular in urban environments, where the received navigation signals can be affected by blockage, shadowing and multipath reception. Latest multipath mitigation algorithms are based on the concept of sequential Bayesian estimation and improve the receiver performance by exploiting the temporal constraints of the channel dynamics, which have to be characterized by a first-order Markovian model for this purpose. In this paper such a channel model is introduced. Simulation results show the benefit of the novel model.
elib2cris::1512001600,krach2009
Keywords: Markovian channel modeling; multipath mitigation; navigation receivers; satellite navigation; sequential Bayesian estimation; Markov processes; satellite navigation

Mathematical View of a XOR-Circuit. - Can, Yavuz (2nd International Baku Scientiﬁc Research Conference, 2021)

Maximizing OFDM Performance through Real Time Adaptivity - Blümm, Christian (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2016)

Maximizing Temperature and Process Corner Performance of Operational Amplifiers with a Novel Self-Adjusting Biasing Technique - Mai, Timo; Hagelauer, Amelie Marietta; Weigel, Robert (Austrian Workshop on Microelectronics, 2018)
A novel self-adjusting biasing technique for current sources in CMOS operational amplifiers is presented. The method is deduced from the fundamental characteristics of a mosfet and a simple line of reasoning. Opamps using this technique can produce a more constant gain over process corners and temperature. This is especially important under large-signal conditions, when the output is near one of the supply rails or a large current needs to be driven. Therefore it reduces worst case distortion in a given Opamp circuit that uses feedback over temperature and process corners. It is also capable of driving low-V_t-devices that typically exhibit less noise, increasing the achievable noise performance of the Opamp almost without additional current consumption. The method was implemented and simulated in tsmc 180 nm CMOS. Simulation results are presented that clearly show the increased performance compared to the state of the art.
Keywords: operational amplifier; gain boosting; adaptive biasing; monticelli; process variations

Measurement of Backscatter RFID-Transponders - Ußmüller, Thomas; Brenk, Daniel; Essel, Jochen; Hsieh, Chia-Yu; Fischer, Georg; Weigel, Robert (14th IEEE International Workshop on Signal Processing Advances in Wireless Communications, 2013)
elib2cris::1512001600,ussmueller2013a

Measurement Setup for X-Parameter Characterization of Bulk Acoustic Wave Resonators - Akstaller, Wolfgang; Tag, Andreas; Musolff, Christian; Weigel, Robert; Hagelauer, Amelie Marietta (85th Microwave Measurement Conference (ARFTG), 2015)
In this work a modern measurement method has been utilized in order to characterize nonlinear behavior of bulk acoustic wave (BAW) solidly mounted resonators (SMR). Unlike typical nonlinearity characterization methods, the method which was employed here not only records amplitudes, but also the phase of generated harmonics. Furthermore, the relations between the harmonics of different order are given. The modeling approach being used is the poly harmonic distortion (PHD) modeling approach, realized by the measurement of X-Parameters. For that purpose it was necessary to extend a nonlinear vector network analyzer (NVNA) by external components in order to enable high power measurements. Afterwards, several optimization steps were required to perform phase calibration. This difficulty arose due to the high power incident tones and steep resonator impedance curves on the one hand and the limited power provided by the phase calibration standard on the other hand.
elib2cris::1512001600,akstaller2015
Keywords: X-Parameter; BAW

Measurements for Onboard Communication in a High-Speed Train up to 330 km/h for Selected Scenarios at 2.45 GHz - Lichtblau, Johann; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (2019 IEEE Radio and Wireless Symposium (RWS), 2019)

Measures of complexity derived from automata theory for characterising cardiological time series - Kirchner, Jens; Meyer, Wolfgang; Schwab, Jörg; Hensel, Bernhard (Biomedizinische Technik. Biomedical engineering, 2005)
In order to obtain information about the regulatory mechanisms of the human cardiovascular system, measures of complexity are used to characterise heart rate variability. A method introduced by Crutchfield and Young [1] for constructing an abstract automaton, which produces a given time series, is applied to cardiological data. We use measures of complexity derived from this model to detect differences between patients with congestive heart failure (CHF) and a reference group of healthy persons.<br

Mechanically Flexible Sensor Array for Current Measurement - Zapf, Florian; Weiss, Roland; Itzke, Alexander; Gordon, Renee; Weigel, Robert (IEEE Transactions on Instrumentation and Measurement, 2020)
Contactless galvanically isolated magnetic field-based current sensors utilizing hard ferromagnetic cores are widely used in many applications, for example, power converters for drives or wind turbines. New measurement methods, e.g., circular arrays of magnetic field sensors, offer some advantages, such as low weight, mechanical flexibility, and independence of the nonlinear and hysteretic behavior of the core. Those sensor arrays can be operated in an open-loop manner or in a closed-loop manner with an additional compensation coil. The advantages of the open-loop design, which we use in this article, are lower cost, lower weight, and the opportunity to realize a mechanically flexible sensor array. In this article, we show the theoretical and experimental influence of the mechanical bending on the accuracy of circular arrays of magnetic field sensors used for current measurement. Furthermore, the inner displacement of the conductor in combination with different bendings is considered. The experimental results were taken with 12, 6, 4, and 3 Hall effect sensors that were uniformly placed on the circular array.
CRIS-Team Scopus Importer:2020-10-09
Keywords: Conductor displacement; contactless current measurement; coreless current sensor; flexible printed circuits; Hall effect sensors; open loop; printed circuit board (PCB) bending; sensor arrays

Mehrwegekompensationsverfahren für Local-Positioning-Radar-Systeme - Neurale Netze und Ausgleichskurven zur Kompensation kurzer Mehrwegeverzerrungen. - Götz, Alexander; Weigel, Robert; Waldmann, Benjamin (RadioTecC - Radio Techniques and Technologies for Commercial Communication and Sensing Applications, 2008)
elib2cris::1512001600,goetz2008a

Mehrwegekompensationsverfahren zur robusten Entfernungs- und Positionsbestimmung - Götz, Alexander; Waldmann, Benjamin; Weigel, Robert (HF-Report, 2009)
elib2cris::1512001600,goetz2009

Merkblatt Beleuchtungstechnik in der Milchviehhaltung - Reiter, Klaus; Werner, Daniel; Pelzer, Andreas (DLG Fachausschuss für Tiergerechtheit, 2015)

Messtechnische Bestimmung des Leuchtdichtekontrasts eines Lichtleitsystems für sehbehinderte und -beeinträchtigte Menschen - Gabel, Kristin; Werner, Daniel; Schwenzfeier-Hellkamp, Eva (PESS2013 (Power and Energy Student Summit), 2013)

Mess- und Bewertungskriterien einer bedarfsorientierten Beleuchtung für Mensch und Tier in der Milchviehhaltung - Werner, Daniel; Greif, Maike; Eßelmann, Christian; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (49. internationalen Tagung Angewandte Ethologie, 2017)

Mess- und Bewertungskriterien einer bedarfsorientierten Beleuchtung für Mensch und Tier in der Milchviehhaltung - Werner, Daniel; Greif, Maike; Reiter, Klaus; Schwenzfeier-Hellkamp, Eva (49. Internationale Tagung Angewandte Ethologie, 2017)

Messung und Simulation frequenzselektiver Indoor Mobilfunkkanäle im 2.45 GHz ISM Band - Huemer, Mario; Pohl, Alfred; Gugler, Wolfgang; Springer, Andreas; Weigel, Robert; Seifert, Franz (DFG-Workshop "Indoor-Mobilkommunikation", 1998)
elib2cris::1512001600,huemer1998b

Metamaterial Strukturen fuer den Einsatz in frequenzagilen Hochfrequenzsystemen - Fischer, Georg (Radar and Communication 2006, RADCOM 2006, 2006)
elib2cris::1512001600,fischer2006a

Method for High Precision Local Positioning Radar using an Ultra Wideband Technique - Waldmann, Benjamin; Weigel, Robert; Gulden, Peter (IEEE MTT-S International Microwave Symposium, 2008)
elib2cris::1512001600,waldmann2008b

Methods for Circuit-Based Automotive EMC Simulation incorporating VHDL-AMS Models - Frank, Florian; Zitzmann, Martin-Ludwig; Steinmair, Gernot; Weigel, Robert (Asia-Pacific Symposium on Electromagnetic Compatibility, 2008)
elib2cris::1512001600,frank2008

Methods for Human Dehydration Measurement - Trenz, Florian; Weigel, Robert; Hagelauer, Amelie Marietta (Frequenz, 2018)
The aim of this article is to give a broad overview of current methods for the identification and quantific- ation of the human dehydration level. Starting off from most common clinical setups, including vital parameters and general patients’ appearance, more quantifiable res- ults from chemical laboratory and electromagnetic meas- urement methods will be reviewed. Different analysis methods throughout the electromagnetic spectrum, ran- ging from direct current (DC) conductivity measurements up to neutron activation analysis (NAA), are discussed on the base of published results. Finally, promising techno- logies, which allow for an integration of a dehydration assessment system in a compact and portable way, will be spotted.
Keywords: hydration; dehydration; physiology; measurement; total body water; body composition

Methods for Low Insertion Loss RF Switches with Increased Power Handling Capability in 65nm CMOS - Rascher, Jochen; Pinarello, Sandro; Müller, Jan-Erik; Fischer, Georg; Weigel, Robert (Asia-Pacific Microwave Conference 2011 (APMC 2011), 2011)
This work reports on methods and dependencies for the design of low insertion loss single pole single throw (SPST) switches in 65nm CMOS with triple well transistors. Two different switch types are investigated and implemented. The series switch has less than 1dB insertion loss at 1.8GHz and a 1dB input compression point (P1dB) of 28.8dBm. The shunt switch has less than 0.4dB insertion loss at 1.8GHz and a P1dB of 29.1dBm. Isolation of the series and shunt switches at 1.8GHz is better than 21dB and 20dB, respectively. By applying a resistive body ﬂoating technique low insertion loss and increased power handling capability are achieved. At the shunt switch negative gate bias is adopted for improved P1dB. At the series switch a method is implemented to boost the DC voltage level at source/ drain nodes of transistors for improved power handling capability in off state without additional circuitry or any DC power consumption. The combination of these methods andan additional DC voltage in on state increases power handling capability in both states of the switch.
elib2cris::1512001600,rascher2011a

Methods to Eliminate Dynamic Errors in High-Performance SAR A/D Converter - Ohnhäuser, Frank; Huemer, Mario (IEEE International Symposium on Circuits and Systems, 2008)
elib2cris::1512001600,ohnhaeuser2008a

Microcontroller.compatible Stabilization and Signal Processing for TDLS Gas Sensor Systems for ISM Applications - Hartmann, Alexander (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2014)

Micromechanical Precision Pressure Sensor Incorporating SAW Delay Line - Jungwirth, Mario; Scherr, Holger; Weigel, Robert (Acta Mechanica, 2002)
We have developed a wireless surface acoustic wave (SAW) pressure sensor operating in the pressure range of 0 Pa to 250 kPa. In order to minimize the temperature sensitivity the pressure sensor is made of on an all-quartz package (AQP), which has been designed with the Finite Element Method. The package of the pressure sensor consists of a diaphragm and a cover, both made of conventional Y-cut quartz. A blind-hole was structured into the sensor cover, By attaching the cover and the diaphragm with an epoxy-adhesive, this blind-hole forms a closed cavity. The SAW element is a reflective delay line (RDL), working at 434 MHz. The RDL consists of ten reflectors and extends over the whole diaphragm. The pressure is determined by evaluating the change of the carrier phase shifts of the reflected impulses at the reflectors. We show that it is possible to minimize the temperature sensitivity and to achieve good linearity by proper positioning of the SAW reflectors. The measurements of the SAW pressure sensor show a deviation from linearity of less than ±0,7%. The temperature dependence is almost negligible in the range from -20/spl deg/C to 100/spl deg/C The objective of this paper is to provide a deeper insight into the behaviour of SAW propagation on pre-stressed substrates. To do so, we start with investigating the behavior of SAWs on stress-free substrates followed by an analysis of SAW propagation on pre-stressed substrates. Further, the requirements on suitable substrate materials for the AQP are specified. Finally, we take advantage of the method of differences to compensate for the temperature dependence of our pressure sensor.
elib2cris::1512001600,jungwirth2002
Keywords: Sensor; SAW

Micromechanical Precision Pressure Sensor Incorporating SAW Delay Line - Scherr, Holger; Weigel, Robert (ASME Mechanics and Materials Conference, 1999)
elib2cris::1512001600,scherr1999

(Micro)metering with Microwaves: A Low-Cost Low-Power High-Precision Radar System - Michler, Fabian; Scheiner, Benedict; Lurz, Fabian; Weigel, Robert; Kölpin, Alexander (IEEE Microwave Magazine, 2019)

Micrometer sensing with microwaves: Precise radar systems for innovative measurement applications - Michler, Fabian; Scheiner, Benedict; Reißland, Torsten; Weigel, Robert; Kölpin, Alexander (IEEE Journal of Microwaves, 2021)

Microstrip-to-Waveguide Transition in Planar Form Using a Substrate Integrated Waveguide - Scheiner, Benedict; Mann, Sebastian; Lurz, Fabian; Michler, Fabian; Erhardt, Stefan; Lindner, Stefan; Weigel, Robert; Kölpin, Alexander (Radio and Wireless Symposium (RWS), 2018 IEEE, 2018)

Microwave Acoustic Materials, Devices, and Applications - Weigel, Robert; Morgan, David; Owens, John; Ballato, Art; Lakin, Kenneth; Hashimoto, Ken-ya; Ruppel, Clemens (IEEE Transactions on Microwave Theory and Techniques, 2002)
This paper surveys applications of acoustic waves in microwave devices. After a general and historical introduction to bulk acoustic waves (BAWs), surface acoustic waves (SAWs), practical wave types, and acoustoelectric transducers, a review is given of technologically important materials for microwave acoustic applications. Following this, we discuss BAW and SAW microwave devices and their technologies. Specifically reviewed are thin-film resonators and filters, transversal filters, and filters for correlative analog signal processing. Finally, an overview of the most important microwave applications is given, along with manufacturing and packaging issues
elib2cris::1512001600,weigel2002b
Keywords: acoustic correlation; acoustic microwave devices; acoustoelectric transducers; bulk acoustic wave devices; packaging; surface acoustic wave correlation; SAWs; Acoustic waves

Microwave Acoustic Wave Devices: Recent Advances on Architectures, Modeling, Materials, and Packaging - Hagelauer, Amelie Marietta; Fattinger, Gernot; Ruppel, Clemens; Ueda, Masanori; Hashimoto, Ken-ya; Tag, Andreas (IEEE Transactions on Microwave Theory and Techniques, 2018)

Microwave and millimeter-wave integrated circuits MTT-6: The RF core chips of the 21st century (guest editorial) - Quay, Rainer; Kissinger, Dietmar (IEEE Microwave Magazine, 2012)
elib2cris::1512001600,quay2012

Microwave-Based Noninvasive Concentration Measurements for Biomedical Applications - Hofmann, Maximilian; Fischer, Georg; Weigel, Robert; Kissinger, Dietmar (IEEE Transactions on Microwave Theory and Techniques, 2013)
A Debye relaxation model for the permittivity of aqueous glucose solution is given up to 40GHz. Measurements of aqueous solutions are compared with invasive measurements on over 40 blood samples. Reflection and transmission based techniques are explained, concerning the application in biomedical concentration measurements. Wideband measurements on different sensing structures are introduced. Reflection and transmission based sensors are applied to a six-port reflectometer as well as a homodyne vector network analyzer (VNA).
elib2cris::1512001600,hofmann2013b

Microwave Design of Multi-Transducer SAW Filters for Mobile Radio Front-End Applications - Weigel, Robert; Fischerauer, Gerhard; Gogl, Dietmar; Russer, Peter (Mikrowellen und Optronik, 1995)
elib2cris::1512001600,weigel1995a

Microwave Interferometer Radar-Based Vital Sign Detection for Driver Monitoring Systems - Vinci, Gabor; Lenhard, Thilo; Will, Christoph; Kölpin, Alexander (IEEE MTT-S International Conference on Microwaves for Intelligent Mobility (ICMIM), 2015)
Autonomous driving is a topic of great importance for our society and is expected to be introduced in the automotive market in a couple of decades. Today, vehicles can already autonomously brake and accelerate in order to avoid crashes with obstacles detected by camera and radar technology. The next step towards autonomous driving is the introduction of driver health monitoring systems. Intensive research is being conducted in this field with the goal of developing a ”biometric driver seat”. In this paper, an interferometric radar-based vital sign detection is presented. The aim is to investigate the applicability of radar technology for vital sign monitoring such as heartbeat and breath rate of the driver with sensors embedded in the seat. The proposed interferometric radar is based on the Six-Port receiver technique and shows excellent performance for the addressed application.
elib2cris::1512001600,vinci2015

Microwave Interferometry for Industrial Applications - Kölpin, Alexander (Workshop Proceedings on Highly Integrated mm-Wave Systems for Emerging Industrial and Consumer Radar-Based Applications, 2017)
Keywords: Six-port; Interferometer

Microwave Sensor for Precise Permittivity Characterization of Liquids Used for Aqueous Glucose Detection in Medical Applications - Schwerthöffer, Udo; Weigel, Robert; Kissinger, Dietmar (German Microwave Conference 2014, 2013)
elib2cris::1512001600,schwerthoeffer2013e

Microwave wideband spectroscopy techniques targeting biomedical sensing applications - Nasr, Ismail; Hofmann, Maximilian; Radwan, Ahmed; Lämmle, Benjamin; Fischer, Georg; Kissinger, Dietmar; Weigel, Robert (Joint Symposium on Opto- and Microelectronic Devices and Circuits, 2012)
elib2cris::1512001600,nasr2012b

Microw(h)att?! Ultralow-Power Six-Port Radar - Lurz, Fabian; Michler, Fabian; Scheiner, Benedict; Weigel, Robert; Kölpin, Alexander (IEEE Microwave Magazine, 2018)

Mikroakustische Duplexer für Multiband- und Multimode-Frontend-Module - Koch, Robert (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2010)

Mikroelektronik, Information, Gesellschaft - Niemann, Heinrich; Seitzer, Dieter; Schüßler, Hans Wilhelm (Springer Verlag, 1983)
UnivIS-Import:2015-07-07:Pub.1983.tech.IMMD.IMMD5.mikroe