GaN HEMT: Trends in civil and military circuit applications

GaN-based High Electron Mobility Transistors (HEMTs) on various substrates have attracted a lot of interest in the last ten years of research and development. Numerous outstanding device results have been achieved, which are currently exploited also on circuit and MMIC level. This paper reviews the state-of-the-art of GaN-HEMT circuit-performance for both civil and military applications. Recent trends in circuit application clearly target the increase of efficiency and reliability on circuit level, also with respect to efficiency in linear operation and with respect to the reliability in complex modes of device operation, e.g., in switch mode operation. Further, the operation of GaN HEMTs up to 100 GHz is discussed on MMIC level.