@misc{KrauseBeleniotisBengtssonetal., author = {Krause, Sascha and Beleniotis, Petros and Bengtsson, Olof and Rudolph, Matthias and Heinrich, Wolfgang}, title = {Characterization of the Impairment and Recovery of GaN-HEMTs in Low-Noise Amplifiers under Input Overdrive}, series = {2021 IEEE MTT-S International Microwave Symposium (IMS), 07-25 June 2021, Atlanta, GA, USA}, journal = {2021 IEEE MTT-S International Microwave Symposium (IMS), 07-25 June 2021, Atlanta, GA, USA}, isbn = {978-1-6654-0307-8}, issn = {2576-7216}, doi = {10.1109/IMS19712.2021.9574839}, pages = {515 -- 518}, language = {en} } @misc{BeleniotisSchniederRudolph, author = {Beleniotis, Petros and Schnieder, Frank and Rudolph, Matthias}, title = {Simulating Drain Lag of GaN HEMTs with physics-based ASM Model}, series = {2020 15th European Microwave Integrated Circuits Conference (EuMIC), 10-15 January 2021, Utrecht, Netherlands}, journal = {2020 15th European Microwave Integrated Circuits Conference (EuMIC), 10-15 January 2021, Utrecht, Netherlands}, isbn = {978-2-87487-060-6}, pages = {165 -- 168}, language = {en} } @misc{BeleniotisChevtchenkoRudolph, author = {Beleniotis, Petros and Chevtchenko, Serguei A. and Rudolph, Matthias}, title = {Statistical Medeling of GaN HEMTs by Direct Transfer of Veriations to Model Parameters}, 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/EuMIC50153.2022.9783780}, pages = {63 -- 66}, language = {en} } @misc{KrauseZervosBeleniotisetal., author = {Krause, Sascha and Zervos, Christos and Beleniotis, Petros and Ritter, Dan and Rudolph, Matthias and Heinrich, Wolfgang}, title = {On the Influence of Transistor Dimensions on the Dispersive Behavior in A1GaN/GaN HEMT-Based PAs and Robust LNAs}, series = {IEEE/MTT-S International Microwave Symposium - IMS 2022, 19-24 June 2022 Denver, CO, USA}, journal = {IEEE/MTT-S International Microwave Symposium - IMS 2022, 19-24 June 2022 Denver, CO, USA}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-9613-1}, doi = {10.1109/IMS37962.2022.9865474}, pages = {914 -- 917}, language = {en} } @misc{BeleniotisSchniederKrauseetal., author = {Beleniotis, Petros and Schnieder, Frank and Krause, Sascha and Haque, Sanaul and Rudolph, Matthias}, title = {An efficient drain-lag model for microwave GaN HEMTs based on ASM-HEMT}, series = {International Journal of Microwave and Wireless Technologie}, volume = {14}, journal = {International Journal of Microwave and Wireless Technologie}, number = {2}, issn = {1759-0795}, doi = {10.1017/S1759078721001483}, pages = {134 -- 142}, language = {en} } @misc{ZervosBeleniotisRudolph, author = {Zervos, Christos and Beleniotis, Petros and Rudolph, Matthias}, title = {Prediction of the large-signal GaN HEMT performance using accurate TCAD-compact modeling method}, series = {2024 19th European Microwave Integrated Circuits Conference (EuMIC)}, journal = {2024 19th European Microwave Integrated Circuits Conference (EuMIC)}, publisher = {IEEE}, doi = {10.23919/EuMIC61603.2024.10732230}, pages = {186 -- 189}, language = {en} } @misc{ZervosBeleniotisRudolph, author = {Zervos, Christos and Beleniotis, Petros and Rudolph, Matthias}, title = {A computational analysis of the impact of thin undoped channels in surface-related current collapse of AlGaN/GaN HEMTs}, series = {Semiconductor Science and Technology}, volume = {39}, journal = {Semiconductor Science and Technology}, number = {9}, publisher = {IOP Publishing}, issn = {0268-1242}, doi = {10.1088/1361-6641/ad689c}, pages = {1 -- 8}, abstract = {Abstract This study provides an insight into the impact of thin purely undoped GaN channel thickness (t ch) on surface-related trapping effects in AlGaN/GaN high electron mobility transistors. Our TCAD study suggests that in cases where parasitic gate leakage is the driving trapping mechanism that promotes the injection of electrons from the Schottky gate contact into surface states, this effect can be alleviated by reducing t ch of the undoped GaN channel. We show that by decreasing t ch from 130 to 10 nm, devices exhibit a reduction in gate-related current collapse under the specific class-B RF operating bias conditions as a consequence of a substantial decrease in the off-state gate leakage with reducing t ch. Large-signal simulations revealed an increase by 3 W mm-1 and about 12\% output power and power-added efficiency due to the decrease of gate-related collapse. This work, for the first time, highlights the role of a proper purely undoped GaN t ch selection to alleviate gate-related surface trapping in the design of GaN-based microwave power amplifiers.}, language = {en} } @misc{BeleniotisKrauseZervosetal., author = {Beleniotis, Petros and Krause, Sascha and Zervos, Christos and Rudolph, Matthias}, title = {A Physics-Based Model for Slow Gate-Induced Electron Trapping in GaN HEMTs}, series = {IEEE Transactions on Electron Devices}, volume = {71}, journal = {IEEE Transactions on Electron Devices}, number = {7}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, issn = {0018-9383}, doi = {10.1109/TED.2024.3397234}, pages = {4058 -- 4065}, language = {en} } @misc{BeleniotisZervosKrauseetal., author = {Beleniotis, Petros and Zervos, Christos and Krause, Sascha and Chevtchenko, Serguei and Ritter, Dan and Rudolph, Matthias}, title = {Investigation of traps impact on PAE and linearity of AlGaN/GaN HEMTs relying on a combined TCAD-compact model approach}, series = {IEEE Transactions on Electron Devices}, volume = {71 (2024)}, journal = {IEEE Transactions on Electron Devices}, number = {6}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, issn = {0018-9383}, doi = {10.1109/TED.2024.3388386}, pages = {3582 -- 3589}, language = {en} } @misc{YazdaniZervosBeleniotisetal., author = {Yazdani, Hossein and Zervos, Christos and Beleniotis, Petros and Brusaterra, Enrico and Hilt, Oliver and Rudolph, Matthias and W{\"u}rfl, Joachim}, title = {Importance of Scaling in RF GaN HEMTs for Reduction of Surface Traps-Induced Drain Lag}, series = {Physica Status Solidi (a)}, journal = {Physica Status Solidi (a)}, publisher = {Wiley}, issn = {1862-6300}, doi = {10.1002/pssa.202300885}, pages = {1 -- 8}, abstract = {Drain lag is a well-known phenomenon that leads to radio frequency performance degradation in AlGaN/GaN high-electron-mobility transistors. Herein, it is demonstrated that a reduction of the gate-to-drain distance (Lgd) from 2.0 to 0.5 μm results in 7\% reduction in the current collapse. This improvement is attributed to a decrease in surface trapping, which, in this case, is found to have a greater impact on current collapse than relatively slow traps in the buffer layer. To support this argument, TCAD simulations are conducted. Load-pull analysis confirms that scaling the devices to Lgd = 0.5 μm provides 15\% better output power density at 10 GHz than Lgd = 2.0 μm. Additionally, a new passivation layer for reduced surface traps exhibits a 20 to 30\% higher output power density and at least a 10\% improvement in power-added efficiency at 20 GHz on a nominally identical GaN-on-semi-insulating SiC epi-wafer.}, 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{HaqueBeleniotisYazdanietal., author = {Haque, Sanaul and Beleniotis, Petros and Yazdani, Hossein and Rudolph, Matthias}, title = {Ka-Band GaN power amplifier with integrated DC supply switch and RF switch}, series = {2024 25th International Microwave and Radar Conference (MIKON)}, journal = {2024 25th International Microwave and Radar Conference (MIKON)}, publisher = {IEEE}, doi = {10.23919/MIKON60251.2024.10633971}, pages = {1 -- 5}, language = {en} } @misc{BeleniotisSchniederChevtchenkoetal., author = {Beleniotis, Petros and Schnieder, Frank and Chevtchenko, Serguei A. and Rudolph, Matthias}, title = {Localization of Trapping Effects in GaN HEMTs with Pulsed S-parameters and Compact Models}, series = {17th European Microwave Integrated Circuits Conference (EuMIC)}, journal = {17th European Microwave Integrated Circuits Conference (EuMIC)}, isbn = {978-2-87487-070-5}, doi = {10.23919/EuMIC54520.2022.9923511}, pages = {149 -- 152}, language = {de} } @misc{ZervosBeleniotisKrauseetal., author = {Zervos, Christos and Beleniotis, Petros and Krause, Sascha and Ritter, Dan and Rudolph, Matthias}, title = {The role of gate leakage on surface-related current collapse in AlGaN/GaN HEMTs}, series = {18th European Microwave Integrated Circuits Conference (EuMIC), 18-19 September 2023, Berlin}, volume = {2023}, journal = {18th European Microwave Integrated Circuits Conference (EuMIC), 18-19 September 2023, Berlin}, isbn = {978-2-87487-073-6}, doi = {10.23919/EuMIC58042.2023.10289036}, pages = {297 -- 300}, language = {en} } @misc{BeleniotisZervosSchniederetal., author = {Beleniotis, Petros and Zervos, Christos and Schnieder, Frank and Rudolph, Matthias}, title = {Dynamic RD Modeling by Exploiting Gate Current Dependency of Virtual Gate Effect}, 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/EuMIC58042.2023.10288955}, pages = {1 -- 4}, language = {en} } @misc{YazdaniBeleniotisBrunneretal., author = {Yazdani, Hossein and Beleniotis, Petros and Brunner, Frank and Ostermay, Ina and W{\"u}rfl, Joachim and Rudolph, Matthias and Heinrich, Wolfgang and Hilt, Oliver}, title = {K/Ka-Band-GaN-High-Electron-Mobility Transistors Technology with 700 mS mm-1 Extrinsic Transconductance}, series = {Physica Status Solidi}, journal = {Physica Status Solidi}, doi = {10.1002/pssa.202400592}, pages = {8}, 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{BeleniotisZervosKrauseetal., author = {Beleniotis, Petros and Zervos, Christos and Krause, Sascha and Yazdani, Hossein and Rudolph, Matthias}, title = {Traps in GaN HEMTs : from characterization to model development and device optimization}, series = {2025 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS)}, journal = {2025 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {979-8-3315-9172-4}, doi = {10.1109/BCICTS63111.2025.11211504}, pages = {1 -- 8}, abstract = {This paper reviews a comprehensive strategy designed to address the impact of traps across the entire field of GaN HEMT operation. It begins with the characterization of trap levels and the measurement of trap time constants. The study then progresses to TCAD simulations to examine the location of the observed trap levels and their effect on device performance. Finally, it introduces the development of a compact trap model grounded in Shockley-Read-Hall statistics. The proposed model is capable of accurately predicting trapping effects across all combinations of voltage, temperature, and time. The paper concludes by highlighting the synergy TCAD-compact-model, underscoring its utility in device optimization schemes.}, language = {en} } @misc{RaoBeleniotisHoffmannetal., author = {Rao, Megha Krishnaji and Beleniotis, Petros and Hoffmann, Thomas and Yazdani, Hossein and Wentzel, Andreas and Rudolph, Matthias}, title = {Switch-integrated GaN LNAs : a technology-focused analysis}, series = {2025 20th European Microwave Integrated Circuits Conference (EuMIC)}, journal = {2025 20th European Microwave Integrated Circuits Conference (EuMIC)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-2-87487-082-8}, doi = {10.23919/EuMIC65284.2025.11234676}, pages = {29 -- 32}, abstract = {This paper presents the first circuit-level analysis of a two-stage GaN-HEMT LNA with an integrated switch, comparing two distinct technologies: one with a standard passivation layer (Type A) and another featuring an advanced passivation layer (Type B). Through a detailed evaluation of their performance in both amplification and isolation modes, the study highlights Type B as a significant advancement over Type A. Leveraging technological enhancements, including an improved passivation layer and slightly optimized component matching, Type B demonstrates superior performance. The results are compelling, with Type B achieving a gain of 19 dB, a low noise figure of 1.17dB, and small-signal isolation exceeding 30 dBm at 5.2 GHz. These achievements establish Type B as a formidable option for future 5G telecommunication systems, offering a performance that challenges traditional designs that use separate switches.}, language = {en} }