Dennler, P.P.DennlerSchwantuschke, DirkDirkSchwantuschkeQuay, RüdigerRüdigerQuayAmbacher, OliverOliverAmbacher2022-03-112022-03-112012https://publica.fraunhofer.de/handle/publica/37666910.1109/MWSYM.2012.62596042-s2.0-84866791565This paper reports on two wide bandwidth monolithic power amplifiers suitable for electronic warfare (EW) systems and other wide bandwidth applications up to the Q-band. The MMICs are based on a 100nm AlGaN/GaN T-gate HEMT microstrip transmission line MMIC technology with an fT>80 GHz. Both designed and fabricated amplifiers use the non-uniform distributed power amplifier (NDPA) topology and cover a frequency range from 8 GHz to 42 GHz, whereas the lower band edge is limited by the on-chip DC bias network. The first MMIC is a single-stage topology with a measured S21 of 6+-1 dB, the second a dual-stage topology with a measured S21 of 14+-2 dB, both over the entire frequency range. By choosing adequate device geometries and a low interstage impedance of 32 in the dual-stage design, the wide bandwidth and high saturated output power of >0.5W of the single-stage design are maintained. A large-signal state-space model was used in the design process. A large-signal methodology for the broadband design of the amplifiers given soft compression of the FETs and low PAE over large bandwidth is proposed and verified.enAlGaN/GaNdistributed amplifiersNDPAbroadband amplifiersHEMTsQ-bandMMWMMIC667conference paper