TY - CHAP A1 - Rudolph, Matthias A1 - Schnieder, Frank A1 - Heinrich, Wolfgang A1 - Schnieder, Frank T1 - Investigation of Thermal Crunching Effects in Fishbone-Type Layout Power GaAs-HBTs Y1 - 2004 ER - TY - GEN A1 - Haque, Sanaul A1 - Schnieder, Frank A1 - Hilt, Oliver A1 - Dörner, Ralf A1 - Brunner, Frank A1 - Rudolph, Matthias T1 - Noise Medeling of GaN/AIN HEMT T2 - 16th European Microwave Integrated Circuits Conference (EuMIC), 03-04 April 2022, London, United Kingdom Y1 - 2022 SN - 978-2-87487-064-4 SN - 978-1-6654-4722-5 U6 - https://doi.org/10.23919/EuMIC50153.2022.9783992 SP - 185 EP - 188 ER - TY - GEN A1 - Bassal, Amer A1 - Chevtchenko, Serguei A. A1 - Schnieder, Frank A1 - Flisgen, Thomas A1 - Bengtsson, Olof A1 - Brunner, Frank A1 - Hilt, Oliver T1 - Impact of parasitic conductive interfaces on the DC and RF performance of GaN‐on‐GaN HEMTs T2 - Physica status solidi (A). Applications and materials science N2 - Radio frequency (RF) AlGaN/GaN high‐electron‐mobility transistors (HEMTs) on semi‐insulating GaN substrates showed an unexpectedly low output power of ≤1.7 W mm⁻¹ and a power added efficiency (PAE) of ≤15% for Vds = 20 V at 20 GHz, despite their good DC current densities (>1 A mm⁻¹) and minor trapping effects in pulsed characterization, comparable to GaN‐on‐SiC HEMTs. With theoretical calculations of Pout and PAE, and the detailed analysis of transistors and structures, a 1500 Ω/□ parasitic conductive interface (PCI) between the GaN substrate and the epitaxial layers was identified as a root cause. GaN substrates suffer from environmental Si contamination forming such a PCI. It was first detected by eddy current measurements showing that the insulating GaN:Fe buffer and GaN:Mn substrate did not effectively suppress the PCI. Nevertheless, it was effectively isolated by the GaN:Fe buffer to maintain a good DC performance for GaN‐on‐GaN HEMTs and allowing for a record gm‐max of 535 mS mm⁻¹. The S‐parameters confirmed this and indicated that the PCI causes a feed‐back effect, reducing the k‐point and fmax. Furthermore, loading effects were revealed on the ports of the HEMTs due to the PCI's resistive nature, and coplanar waveguide measurements showed 5 dB mm⁻¹ of propagation loss and severe changes in the characteristic impedance. Y1 - 2025 U6 - https://doi.org/10.1002/pssa.202500406 SP - 1 EP - 10 PB - Wiley CY - Hoboken, NJ ER - TY - CHAP A1 - Rudolph, Matthias A1 - Flucke, Jens A1 - Schnieder, Frank A1 - Schmückle, Franz-Josef A1 - Heinrich, Wolfgang T1 - On the magnetic coupling between bondwires in power-transistor packages Y1 - 2010 ER - TY - JOUR A1 - Rudolph, Matthias A1 - Schnieder, Frank A1 - Heinrich, Wolfgang T1 - Modeling Emitter Breakdown in GaAs-Based HBTs Y1 - 2002 ER - TY - CHAP A1 - Rudolph, Matthias A1 - Schnieder, Frank A1 - Schmückle, Franz-Josef A1 - Heinrich, Wolfgang T1 - An Analysis of Source Connections in GaN Power Transistor Packages T2 - Proceedings, Microwave Conference (GeMiC), 2012 The 7th in Ilmenau, Germany Y1 - 2012 SN - 978-3-9812668-4-9 CY - Ilmenau ER - TY - GEN A1 - Schnieder, Frank A1 - Rudolph, Matthias T1 - Thermal Coupling in AlGaN/GaN Power Transistors T2 - Frequenz Y1 - 2013 U6 - https://doi.org/10.1515/freq-2012-0031 SN - 2191-6349 SN - 0016-1136 VL - 67 IS - 1-2 SP - 21 EP - 26 ER - TY - GEN A1 - Johansen, Tom K. A1 - Rudolph, Matthias A1 - Jensen, Thomas A1 - Kraemer, Tomas A1 - Weimann, Nils A1 - Schnieder, Frank A1 - Krozer, Viktor A1 - Heinrich, Wolfgang T1 - Modeling of InP HBTs in Transferred-Substrate Technology for Millimeter-Wave Applications T2 - Microwave Integrated Circuits Conference (EuMIC), 2013, 8th European, 6–8 October 2013 Nuremberg, Germany Y1 - 2013 SN - 978-2-87487-032-3 SP - 280 EP - 283 PB - IEEE CY - Piscataway, NJ ER - TY - GEN A1 - Schnieder, Frank A1 - Bengtsson, Olof A1 - Schmückle, Franz-Josef A1 - Rudolph, Matthias A1 - Heinrich, Wolfgang T1 - Simulation of RF Power Distribution in a Packaged GaN Power Transistor Using an Electro-Thermal Large-Signal Description T2 - IEEE transactions on microwave theory and techniques Y1 - 2013 U6 - https://doi.org/10.1109/TMTT.2013.2261089 SN - 0018-9480 VL - 61 IS - 7 SP - 2603 EP - 2609 ER - TY - GEN A1 - Johansen, Tom K. A1 - Rudolph, Matthias A1 - Jensen, Thomas A1 - Kraemer, Tomas A1 - Weimann, Nils A1 - Schnieder, Frank A1 - Krozer, Viktor A1 - Heinrich, Wolfgang T1 - Small- and large-signal modeling of InP HBTs in transferred-substrate technology T2 - International Journal of Microwave and Wireless Technologies Y1 - 2014 U6 - https://doi.org/10.1017/S1759078714000051 VL - 6 IS - 3-4 SP - 243 EP - 251 ER -