@inproceedings{RudolphAndreiLieroetal., author = {Rudolph, Matthias and Andrei, Cristina and Liero, Armin and Lossy, Richard and Heinrich, Wolfgang}, title = {Highly Linear Broadband GaN-based Low-noise Amplifier}, language = {en} } @inproceedings{AndreiDoernerBengtssonetal., author = {Andrei, Cristina and D{\"o}rner, Ralf and Bengtsson, Olof and Chevtchenko, Serguei A. and Heinrich, Wolfgang and Rudolph, Matthias}, title = {Highly Linear X-Band GaN-Based Low-Noise Amplifier}, series = {Signals, Systems, and Electronics (ISSSE), 2012 International Symposium on , Potsdam}, booktitle = {Signals, Systems, and Electronics (ISSSE), 2012 International Symposium on , Potsdam}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-4454-8}, language = {en} } @inproceedings{AndreiBengtssonDoerneretal., author = {Andrei, Cristina and Bengtsson, Olof and D{\"o}rner, Ralf and Chevtchenko, Serguei A. and Heinrich, Wolfgang and Rudolph, Matthias}, title = {Dynamic behaviour of a Low-Noise Amplifier GaN MMIC under input power overdrive}, series = {Proceedings of 45th European Microwave Conference, Paris 2015}, booktitle = {Proceedings of 45th European Microwave Conference, Paris 2015}, publisher = {IEEE}, doi = {10.1109/EuMC.2015.7345742}, pages = {231 -- 234}, language = {en} } @inproceedings{AndreiBengtssonDoerneretal., author = {Andrei, Cristina and Bengtsson, Olof and D{\"o}rner, Ralf and Chevtchenko, Serguei A. and Rudolph, Matthias}, title = {Robust Stacked GaN-Based Low-Noise Amplifier MMIC for Receiver Applications}, series = {IEEE MTT-S International Microwave Symposium (IMS), 17-22 May 2015}, booktitle = {IEEE MTT-S International Microwave Symposium (IMS), 17-22 May 2015}, publisher = {IEEE}, doi = {10.1109/MWSYM.2015.7166766}, pages = {4}, language = {en} } @inproceedings{RudolphAndreiDoerneretal., author = {Rudolph, Matthias and Andrei, Cristina and D{\"o}rner, Ralf and Chevtchenko, Serguei A. and Heinrich, Wolfgang}, title = {Noise in GaN HEMTs and Circuits}, series = {24th International Conference on Noise and Fluctuations (ICNF), Vilnius, Lithuania, June 20-23, 2017}, booktitle = {24th International Conference on Noise and Fluctuations (ICNF), Vilnius, Lithuania, June 20-23, 2017}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-5090-2760-6}, doi = {10.1109/ICNF.2017.7985978}, pages = {1 -- 4}, language = {en} } @inproceedings{AndreiDoernerChevtchenkoetal., author = {Andrei, Cristina and D{\"o}rner, Ralf and Chevtchenko, Serguei A. and Heinrich, Wolfgang and Rudolph, Matthias}, title = {On the Optimization of GaN HEMT Layout for Highly Rugged Low-Noise Amplifier Design}, series = {12th European Microwave Integrated Circuits Conference (EuMIC), 8-10 Oct. 2017, Nuremberg, Germany}, booktitle = {12th European Microwave Integrated Circuits Conference (EuMIC), 8-10 Oct. 2017, Nuremberg, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-2-87487-048-4}, doi = {10.23919/EuMIC.2017.8230705}, pages = {244 -- 247}, language = {en} } @misc{KauleAndreiGerlichetal., author = {Kaule, Evelyne and Andrei, Cristina and Gerlich, Stefan and D{\"o}rner, Ralf and Rudolph, Matthias}, title = {Limiting the Output Power of Rugged GaN LNAs}, series = {14th European Microwave Integrated Circuits Conference (EuMIC)}, journal = {14th European Microwave Integrated Circuits Conference (EuMIC)}, address = {Paris, France}, isbn = {978-2-87487-056-9}, doi = {10.23919/EuMIC.2019.8909653}, pages = {240 -- 242}, abstract = {Rugged GaN HEMT low-noise amplifiers are well established, but the common concept of achieving ruggedness by applying the gate supply voltage through a high ohmic resistance might not be sufficient in addition to control the maximum output power. This paper shifts the focus to the protection of subsequent stages and proposes a circuit concept based on an output attenuator and an adaptive drain supply. It is shown that the concept implementation provides an attenuation of up to 28dB under input overdrive condition while leaving small-signal noise Figure unaffected.}, language = {en} } @misc{KauleAndreiGerlichetal., author = {Kaule, Evelyne and Andrei, Cristina and Gerlich, Stefan and D{\"o}rner, Ralf and Rudolph, Matthias}, title = {Limiting the Output Power of Rugged GaN LNAs}, series = {Proceedings of 49th European Microwave Conference (EuMC)}, journal = {Proceedings of 49th European Microwave Conference (EuMC)}, address = {Paris, France}, isbn = {978-2-87487-055-2}, doi = {10.23919/EuMC.2019.8910675}, pages = {794 -- 796}, abstract = {Rugged GaN HEMT low-noise amplifiers are well established, but the common concept of achieving ruggedness by applying the gate supply voltage through a high ohmic resistance might not be sufficient in addition to control the maximum output power. This paper shifts the focus to the protection of subsequent stages and proposes a circuit concept based on an output attenuator and an adaptive drain supply. It is shown that the concept implementation provides an attenuation of up to 28 dB under input overdrive condition while leaving small-signal noise figure unaffected.}, language = {en} } @misc{AndreiRudolph, author = {Andrei, Cristina and Rudolph, Matthias}, title = {Properties of GaN LNAs for Front-End Applications}, series = {WFC Towards A One-Chip Solution for GaN Front-Ends, Microwave Symposiums, Boston, 2019}, journal = {WFC Towards A One-Chip Solution for GaN Front-Ends, Microwave Symposiums, Boston, 2019}, language = {en} } @misc{FischerMarchettiDeschmannAssisetal., author = {Fischer, Thomas and Marchetti-Deschmann, Martina and Assis, Ana Cristina and Elad, Michal Levin and Algarra, Manuel and Barac, Marko and Bogdanovic Radovic, Iva and Cicconi, Flavio and Claes, Britt and Frascione, Nunzianda and George, Sony and Guedes, Alexandra and Heaton, Cameron and Heeren, Ron and Lasic, Violeta and Lerma, Jos{\´e} Luis and Valle Martinez de Yuso Garcia, Maria del and Nosko, Martin and O'Hara, John and Oshina, Ilze and Palucci, Antonio and Pawlaczyk, Aleksandra and Posp{\´i}škov{\´a}, Krist{\´y}na and de Puit, Marcel and Radodic, Ksenija and Rēpele, Māra and Ristova, Mimoza and Romolo, Francesco Saverio and Šafař{\´i}k, Ivo and Siketic, Zdravko and Spigulis, Janis and Szynkowska-Jozwik, Malgorzata Iwona and Tsiatsiuyeu, Andrei and Vella, Joanna and Dawson, Lorna and R{\"o}diger, Stefan and Francese, Simona}, title = {Profiling and imaging of forensic evidence - A pan-European forensic round robin study part 1: Document forgery}, series = {Science \& Justice}, volume = {62}, journal = {Science \& Justice}, number = {4}, issn = {1876-4452}, doi = {10.1016/j.scijus.2022.06.001}, pages = {433 -- 447}, language = {en} } @misc{KauleAndreiRudolph, author = {Kaule, Evelyne and Andrei, Cristina and Rudolph, Matthias}, title = {Output Power Limited Rugged GaN LNA MMIC}, series = {16th European Microwave Integrated Circuits Conference (EuMIC), 03-04 April 2022, London, United Kingdom}, journal = {16th European Microwave Integrated Circuits Conference (EuMIC), 03-04 April 2022, London, United Kingdom}, isbn = {978-2-87487-064-4}, doi = {10.23919/EUMIC50153.2022.9784020}, pages = {133 -- 135}, language = {en} } @misc{TomazGerlichRudolphetal., author = {Tomaz, Antonio and Gerlich, Stefan and Rudolph, Matthias and Andrei, Cristina}, title = {A Novel System for Recovery Time Measurements of GaN-Based Low-Noise Amplifiers}, series = {2022 14th German Microwave Conference (GeMiC), Ulm, 16-18 May 2022}, journal = {2022 14th German Microwave Conference (GeMiC), Ulm, 16-18 May 2022}, publisher = {IEEE}, isbn = {978-3-9820397-2-5}, issn = {2167-8022}, pages = {65 -- 68}, abstract = {A novel setup allowing for recovery time measurement of robust GaN LNA is presented in this paper. The setup is based on an PNA-X vector network analyzer and allows for the characterization of the LNA's small-signal gain, while it also monitors overdrive pulse power and reflected pulse power. The system setup and operation is shown in detail. As an example, two different GaN LNAs were measured in order to validate the test setup.}, language = {en} } @misc{ManchandaAndreiTostetal., author = {Manchanda, Prabhav and Andrei, Cristina and Tost, Frank and Rudolph, Matthias}, title = {A pHEMT based power detector for radar applications}, series = {2024 54th European Microwave Conference (EuMC)}, journal = {2024 54th European Microwave Conference (EuMC)}, publisher = {IEEE}, doi = {10.23919/EuMC61614.2024.10732043}, pages = {992 -- 995}, language = {en} } @misc{HaqueAndreiWolfetal., author = {Haque, Sanaul and Andrei, Cristina and Wolf, Mihaela and Hilt, Oliver and Rudolph, Matthias}, title = {Switch integrated Ka-Band low noise amplifier in GaN/AlN HEMT technology}, series = {2024 19th European Microwave Integrated Circuits Conference (EuMIC)}, journal = {2024 19th European Microwave Integrated Circuits Conference (EuMIC)}, publisher = {IEEE}, doi = {10.23919/EuMIC61603.2024.10732731}, pages = {351 -- 354}, language = {en} } @misc{RudolphBeleniotisZervosetal., author = {Rudolph, Matthias and Beleniotis, Petros and Zervos, Christos and Rohde, Ulrich L. and Andrei, Cristina}, title = {Determining GaN HEMT trap models from MHz load-line measurement : a case study}, series = {2024 15th German Microwave Conference (GeMiC)}, journal = {2024 15th German Microwave Conference (GeMiC)}, publisher = {IEEE}, doi = {10.23919/GeMiC59120.2024.10485297}, pages = {29 -- 32}, language = {en} } @misc{KauleLuoChevtchenkoetal., author = {Kaule, Evelyne and Luo, Peng and Chevtchenko, Serguei A. and Andrei, Cristina and Rudolph, Matthias}, title = {Analysis for the optimization of a rugged GaN low-noise amplifier MMIC with a compact stacked first amplifier stage}, series = {2024 IEEE International Conference on Microwaves, Communications, Antennas, Biomedical Engineering and Electronic Systems (COMCAS)}, journal = {2024 IEEE International Conference on Microwaves, Communications, Antennas, Biomedical Engineering and Electronic Systems (COMCAS)}, publisher = {IEEE}, doi = {10.1109/COMCAS58210.2024.10666226}, pages = {1 -- 4}, language = {en} } @misc{HaqueAndreiYazdanietal., author = {Haque, Sanaul and Andrei, Cristina and Yazdani, Hossein and Rudolph, Matthias}, title = {On the Survivability of a 28 - 32 GHz GaN Low Noise Amplifier}, series = {18th European Microwave Integrated Circuits Conference (EuMIC), 18-19 September 2023, Berlin}, journal = {18th European Microwave Integrated Circuits Conference (EuMIC), 18-19 September 2023, Berlin}, isbn = {978-2-87487-073-6}, doi = {10.23919/EuMIC58042.2023.10288728}, pages = {4}, language = {de} } @misc{KauleLuoChevtchenkoetal., author = {Kaule, Evelyne and Luo, Peng and Chevtchenko, Serguei A. and Rudolph, Matthias and Andrei, Cristina}, title = {Compact Stacked Rugged GaN Low-Noise Amplifier MMIC under Input Power Overdrive Condition}, series = {18th European Microwave Integrated Circuits Conference (EuMIC),18-19 September 2023, Berlin}, journal = {18th European Microwave Integrated Circuits Conference (EuMIC),18-19 September 2023, Berlin}, isbn = {978-2-87487-073-6}, doi = {10.23919/EuMIC58042.2023.10288650}, pages = {9 -- 12}, language = {en} } @misc{BeleniotisAndreiZervosetal., author = {Beleniotis, Petros and Andrei, Cristina and Zervos, Christos and Rohde, Ulrich L. and Rudolph, Matthias}, title = {GaN trap model extraction based on MHz load-line measurements}, series = {2025 IEEE/MTT-S International Microwave Symposium - IMS 2025}, journal = {2025 IEEE/MTT-S International Microwave Symposium - IMS 2025}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {979-8-3315-1409-9}, doi = {10.1109/IMS40360.2025.11104000}, pages = {1059 -- 1062}, abstract = {The extraction of model parameters for GaN HEMTs is a challenging task that typically requires a comprehensive series of pulsed measurements to ensure that the resulting model is both accurate and convergence-stable. This study introduces, for the first time, an extraction procedure that utilizes I-V curves generated by MHz load-line measurements, effectively replacing the complex and time-intensive pulsed measurements. A drain-lag model extraction was based on load-line I-V curves and validated along with a pulsed-IV-based model through RF large-signal simulations, demonstrating excellent performance.}, language = {en} } @misc{BeleniotisAndreiRohdeetal., author = {Beleniotis, Petros and Andrei, Cristina and Rohde, Ulrich L. and Rudolph, Matthias}, title = {Determining GaN HEMT trap models from MHz load-line measurement — synthesis and evaluation}, series = {2025 16th German Microwave Conference (GeMiC)}, journal = {2025 16th German Microwave Conference (GeMiC)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-3-9820397-4-9}, doi = {10.23919/GeMiC64734.2025.10978988}, pages = {451 -- 454}, abstract = {The modeling of GaN HEMTs is closely associated with pulsed measurements, which are essential for extracting model parameters related to trapping and thermal effects. However, these characterizations are often hindered by high costs and the time-intensive nature of the measurement process. In this paper, we present and evaluate a novel approach for trap model extraction that utilizes MHz load-line measurements. Our analysis includes a comparative study of the measurements and a demonstration of modeling based on the proposed methodology.}, language = {en} } @misc{ManchandaKnaackTostetal., author = {Manchanda, Prabhav and Knaack, Marcus and Tost, Frank and Andrei, Cristina and Rudolph, Matthias}, title = {Digitally reconfigurable power detector}, series = {2025 16th German Microwave Conference (GeMiC)}, journal = {2025 16th German Microwave Conference (GeMiC)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-3-9820397-4-9}, doi = {10.23919/GeMiC64734.2025.10979055}, pages = {439 -- 442}, abstract = {This paper presents a reconfigurable diode detector operating at 24 GHz, capable of dynamically adjusting its output voltage and linear range through digital control of the load impedance. The variation in load impedance is initially achieved by employing a variable resistor within the baseband amplifier. Subsequently, the same effect is accomplished using a fully digital solution by configuring the internal programmable gain amplifier (PGA) of an analog-to-digital converter (ADC). The detector, the baseband amplifier, and the ADC are fabricated using commercially available components. Experimental results demonstrate that the linear range can be extended significantly by reducing the input impedance of the baseband amplifier, whereas an increase in impedance results in an elevated output voltage. Similar trends are observed when utilizing the PGA within the ADC. The results demonstrate a reconfigurable diode detector that employs digital control to dynamically optimize performance metrics, including output voltage and linear range. This adaptability renders it highly versatile and well-suited for a broad spectrum of modern RF system applications.}, language = {en} } @misc{ManchandaKnaackLiaoetal., author = {Manchanda, Prabhav and Knaack, Marcus and Liao, Juhua and Andrei, Cristina and Rudolph, Matthias}, title = {Detection of vital signs using noncoherent receivers}, series = {2025 22nd European Radar Conference (EuRAD)}, journal = {2025 22nd European Radar Conference (EuRAD)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-2-87487-083-5}, doi = {10.23919/EuRAD65285.2025.11233845}, pages = {363 -- 366}, abstract = {This work introduces a novel concept for detecting displacements, specifically vital signs resulting from physiological activity, using noncoherent receivers. A theoretical analysis of phase noise propagation in the receiver architecture reveals that individual uncorrelated phase noise contributions add at the intermediate frequency, thereby defining the detection sensitivity. System validation using a reflector mounted on a modulator producing controlled oscillations demonstrates the ability to detect sub-millimeter displacements, provided the residual phase noise from the uncorrelated oscillators remains low. Extending this concept, the system accurately detects respiration and cardiac activity, with results is comparable to those of a reference ECG sensor. These findings open new possibilities for multistatic vital sign detection systems, offering reliable, non-contact sensing for healthcare and remote monitoring applications.}, language = {en} } @misc{OkochaAndreiRudolph, author = {Okocha, Jonathan and Andrei, Cristina and Rudolph, Matthias}, title = {On the repeatability of low cost varactor—based RF impedance tuners}, series = {2025 55th European Microwave Conference (EuMC)}, journal = {2025 55th European Microwave Conference (EuMC)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-2-87487-081-1}, doi = {10.23919/EuMC65286.2025.11234977}, pages = {683 -- 686}, abstract = {This paper introduces a concise methodology for assessing the repeatability of low-cost, varactor-based RF impedance tuners by employing a dB-based metric that quantifies how accurately each tuner reproduces a target impedance over repeated cycles. Both blocked and cyclical measurement strategies are used to highlight large impedance transitions near high-reflection states that exacerbate non-idealities. In addition, the method rigorously characterizes issues such as systematic offsets, drift, and hysteresis, common challenges that can impair tuner performance, allowing targeted improvements. Demonstrations with a BST varactor prototype underscore the importance of identifying and quantifying these effects to ensure consistent tuner performance in real-world RF testing environments.}, language = {en} }