Highly efficient compact Q-band MMIC power amplifier using 2-mil substrate and partially-matched output

Abstract

Presented is an 850 mW Q-band PHEMT MMIC power amplifier with a peak efficiency of 34% at 45.5 GHz, believed to be the highest reported at this power level and frequency. The compact amplifier (3.6 mm by 1.6 mm) features the use of a thinned 2-mil GaAs substrate and off-chip output matching and combining on a 5-mil alumina substrate.