Harmonic termination of AlGaN/GaN/(Al)GaN single- and double-heterojunction HEMTs

This paper gives a systematic comparison of inputand output-second-harmonic termination in X-frequency-band MMICs (8-12 GHz) based on advanced single- and doubleheterojunction AlGaN/GaN/(Al)GaN high electron mobility transistors (HEMTs) on SiC substrates. High-efficiency designstrategies are key to make use of the outstanding power capability in group-III-nitride MMICs. The study deals with the bandwidth trade-offs associated with reaching very high PAE-values beyond 55% at 10GHz in cw-operation to a 50Ohm-load.