Hermann Schumacher | Universität Ulm (original) (raw)
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Papers by Hermann Schumacher
2016 Global Symposium on Millimeter Waves (GSMM) & ESA Workshop on Millimetre-Wave Technology and Applications, 2016
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2015
2017 IEEE 30th Conference on Software Engineering Education and Training (CSEE&T), 2017
Proceedings of the 1996 BIPOLAR/BiCMOS Circuits and Technology Meeting
2016 IEEE MTT-S International Microwave Symposium (IMS), 2016
This paper presents a VCO that utilizes the analog capacitive tuning properties of a MEMS varacto... more This paper presents a VCO that utilizes the analog capacitive tuning properties of a MEMS varactor for continuous frequency tuning. The MEMS based VCO achieves a tuning range from 3.37 to 3.58 GHz and a superior phase noise performance of -134.5 dBc/Hz at a 500 kHz offset from the carrier. This work shows the potential of MEMS varactors as attractive alternative to standard varactor solutions for frequency tuning of high performance VCOs.
IEEE Transactions on Circuits and Systems I: Regular Papers, 2017
2016 IEEE MTT-S International Microwave Symposium (IMS), 2016
Heterodyne and direct detection radiometer receivers at 94 GHz have been realized in a 130 nm Si/... more Heterodyne and direct detection radiometer receivers at 94 GHz have been realized in a 130 nm Si/SiGe BiCMOS process. They have been assembled into fully self-contained metal housings with a waveguide flange for the antenna connection. The receivers, which employ a SiGe LNA with below 4 dB noise figure, show overall responsivities of 620 μV/K and 380 μV/K respectively.
Microwave and Optical Technology Letters, 2015
ABSTRACT
International Technical Digest on Electron Devices
Electronics Letters, 2003
gaasmantech.com
In this paper several existing industrial GaAs MIM-capacitor processes were evaluated regarding t... more In this paper several existing industrial GaAs MIM-capacitor processes were evaluated regarding their suitability for use with high-voltage GaN MMIC technologies. These processes were tested using different time domain voltage stress methods from which lifetime estimations based on the linear field model were calculated. In addition the influence of electrode geometries and dielectric thicknesses on capacitor performance was investigated. Furthermore early device failures were correlated with defects detected on ...
Abstract—Tunable microstrip filters, phase shifting elements, and switches in the GHz range were ... more Abstract—Tunable microstrip filters, phase shifting elements, and switches in the GHz range were previously realized in a low complexity technology. This paper now presents time dependent measurements of the RF-signal to evaluate the switching behavior of this technology. The measured switching time for a 300µm long cantilever in air is below 75µs. It depends on the amplitude and the sign of the DC actuation due to semiconductor effects in the actuation path that lead to a delay of 60µs before the cantilever starts to move down. ...
Nachhaltigkeit in der wissenschaftlichen Weiterbildung, 2017
Online courses and incorporation of e-learning elements in traditional courses are becoming incre... more Online courses and incorporation of e-learning elements in traditional courses are becoming increasingly popular. Switching to an online format is often seen as beneficial to students and educators alike. However, online courses often struggle with teaching complex topics where solutions are not either correct or incorrect but come in different degrees of appropriateness. While models created for model-based engineering must fulfill various rules to be considered suitable, usually various, often equally well suited alternatives exist. In this talk we report our experience from creating and teaching an online course for model based engineering and explain how we handled the need for individualized feedback to modeling exercises.
A first SiGe bipolar heterojunction phototransistor developed in a commercial available SiGe/Si t... more A first SiGe bipolar heterojunction phototransistor developed in a commercial available SiGe/Si technology is presented.Emphasis on the development of a complete numerical model for the simulation of strained- SiGe based devices is given.The SiGe HPT exhibits a dc opto-microwave power gain of 3.46dB,i.e.a responsivity with 50Ohms loads of 1.49A/W,and a –3dB bandwidth of 0.4GHz at 940nm.Power budgets are drawn with the use of the opto-microwave power gain 's monogram chart.
A new, analytic large-signal model for N-channel SiGe Modulation Doped Field Ef-fect Transistors ... more A new, analytic large-signal model for N-channel SiGe Modulation Doped Field Ef-fect Transistors (MODFETs) is presented. The model is based on a non-linear equivalent circuit and can be employed to fit the characteristics in the sub-threshold, linear and saturation operating region from DC to high frequencies. In addition to the non-linear I ds current source, gate/drain-and gate/source capacitance elements, it contains a dispersion model to account for the observed low-frequency dispersion effects in the devices. This contribution focuses on the reliable pre-diction of large-signal characteristics such as gain compression and third order intercept points by ex-tending the covered gate-source and drain-source voltage regimes of the model. Device characterisa-tion has been carried out up to 50GHz and allows for the extension of the model's valid frequency range well beyond the device's measured transit frequency of around 40GHz.
An original approach based on a physical model is used to evaluate opto-microwave performances of... more An original approach based on a physical model is used to evaluate opto-microwave performances of avertically illuminated single strained layer SiGe HPT. Analysis of optomicrowave performance is presented at 940nm. The contribution of each regionon the dynamic performances is studied. Frequency response enhancement is shown for base optical detection first and also by wavelength analysis while maintaining whole component detection. Increases up to a 9. 8 factor for the transition optical frequency (fTopt)in phototransistor mode are presented, reaching respectively 19.7 GHz and 15.3 GHz.
This paper deals with an Integrated Circuits (ICs) compatible MEMS technology, which is used to e... more This paper deals with an Integrated Circuits (ICs) compatible MEMS technology, which is used to elaborate an ultra compact RF communication module centered at 24GHz. This technology uses conventional equipments and is in adequation with millimeterwave applications. A compatibility test protocol has consequently been defined in order to check that each technological step does not degrade the SiGe circuits' performances. Finally, the realized demonstrator present a total surface of only 9mm².
33rd European Microwave Conference, 2003, 2003
Journal of Signal Processing Systems, 2016
2016 Global Symposium on Millimeter Waves (GSMM) & ESA Workshop on Millimetre-Wave Technology and Applications, 2016
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2015
2017 IEEE 30th Conference on Software Engineering Education and Training (CSEE&T), 2017
Proceedings of the 1996 BIPOLAR/BiCMOS Circuits and Technology Meeting
2016 IEEE MTT-S International Microwave Symposium (IMS), 2016
This paper presents a VCO that utilizes the analog capacitive tuning properties of a MEMS varacto... more This paper presents a VCO that utilizes the analog capacitive tuning properties of a MEMS varactor for continuous frequency tuning. The MEMS based VCO achieves a tuning range from 3.37 to 3.58 GHz and a superior phase noise performance of -134.5 dBc/Hz at a 500 kHz offset from the carrier. This work shows the potential of MEMS varactors as attractive alternative to standard varactor solutions for frequency tuning of high performance VCOs.
IEEE Transactions on Circuits and Systems I: Regular Papers, 2017
2016 IEEE MTT-S International Microwave Symposium (IMS), 2016
Heterodyne and direct detection radiometer receivers at 94 GHz have been realized in a 130 nm Si/... more Heterodyne and direct detection radiometer receivers at 94 GHz have been realized in a 130 nm Si/SiGe BiCMOS process. They have been assembled into fully self-contained metal housings with a waveguide flange for the antenna connection. The receivers, which employ a SiGe LNA with below 4 dB noise figure, show overall responsivities of 620 μV/K and 380 μV/K respectively.
Microwave and Optical Technology Letters, 2015
ABSTRACT
International Technical Digest on Electron Devices
Electronics Letters, 2003
gaasmantech.com
In this paper several existing industrial GaAs MIM-capacitor processes were evaluated regarding t... more In this paper several existing industrial GaAs MIM-capacitor processes were evaluated regarding their suitability for use with high-voltage GaN MMIC technologies. These processes were tested using different time domain voltage stress methods from which lifetime estimations based on the linear field model were calculated. In addition the influence of electrode geometries and dielectric thicknesses on capacitor performance was investigated. Furthermore early device failures were correlated with defects detected on ...
Abstract—Tunable microstrip filters, phase shifting elements, and switches in the GHz range were ... more Abstract—Tunable microstrip filters, phase shifting elements, and switches in the GHz range were previously realized in a low complexity technology. This paper now presents time dependent measurements of the RF-signal to evaluate the switching behavior of this technology. The measured switching time for a 300µm long cantilever in air is below 75µs. It depends on the amplitude and the sign of the DC actuation due to semiconductor effects in the actuation path that lead to a delay of 60µs before the cantilever starts to move down. ...
Nachhaltigkeit in der wissenschaftlichen Weiterbildung, 2017
Online courses and incorporation of e-learning elements in traditional courses are becoming incre... more Online courses and incorporation of e-learning elements in traditional courses are becoming increasingly popular. Switching to an online format is often seen as beneficial to students and educators alike. However, online courses often struggle with teaching complex topics where solutions are not either correct or incorrect but come in different degrees of appropriateness. While models created for model-based engineering must fulfill various rules to be considered suitable, usually various, often equally well suited alternatives exist. In this talk we report our experience from creating and teaching an online course for model based engineering and explain how we handled the need for individualized feedback to modeling exercises.
A first SiGe bipolar heterojunction phototransistor developed in a commercial available SiGe/Si t... more A first SiGe bipolar heterojunction phototransistor developed in a commercial available SiGe/Si technology is presented.Emphasis on the development of a complete numerical model for the simulation of strained- SiGe based devices is given.The SiGe HPT exhibits a dc opto-microwave power gain of 3.46dB,i.e.a responsivity with 50Ohms loads of 1.49A/W,and a –3dB bandwidth of 0.4GHz at 940nm.Power budgets are drawn with the use of the opto-microwave power gain 's monogram chart.
A new, analytic large-signal model for N-channel SiGe Modulation Doped Field Ef-fect Transistors ... more A new, analytic large-signal model for N-channel SiGe Modulation Doped Field Ef-fect Transistors (MODFETs) is presented. The model is based on a non-linear equivalent circuit and can be employed to fit the characteristics in the sub-threshold, linear and saturation operating region from DC to high frequencies. In addition to the non-linear I ds current source, gate/drain-and gate/source capacitance elements, it contains a dispersion model to account for the observed low-frequency dispersion effects in the devices. This contribution focuses on the reliable pre-diction of large-signal characteristics such as gain compression and third order intercept points by ex-tending the covered gate-source and drain-source voltage regimes of the model. Device characterisa-tion has been carried out up to 50GHz and allows for the extension of the model's valid frequency range well beyond the device's measured transit frequency of around 40GHz.
An original approach based on a physical model is used to evaluate opto-microwave performances of... more An original approach based on a physical model is used to evaluate opto-microwave performances of avertically illuminated single strained layer SiGe HPT. Analysis of optomicrowave performance is presented at 940nm. The contribution of each regionon the dynamic performances is studied. Frequency response enhancement is shown for base optical detection first and also by wavelength analysis while maintaining whole component detection. Increases up to a 9. 8 factor for the transition optical frequency (fTopt)in phototransistor mode are presented, reaching respectively 19.7 GHz and 15.3 GHz.
This paper deals with an Integrated Circuits (ICs) compatible MEMS technology, which is used to e... more This paper deals with an Integrated Circuits (ICs) compatible MEMS technology, which is used to elaborate an ultra compact RF communication module centered at 24GHz. This technology uses conventional equipments and is in adequation with millimeterwave applications. A compatibility test protocol has consequently been defined in order to check that each technological step does not degrade the SiGe circuits' performances. Finally, the realized demonstrator present a total surface of only 9mm².
33rd European Microwave Conference, 2003, 2003
Journal of Signal Processing Systems, 2016