Quasi-monolithic 4-GHz power amplifiers with 65-percent power-added efficiency

Abstract

A highly miniaturized C-band 1-W GaAs FET amplifier, part of a three-stage power amplifier for communications satellite applications, has been designed, fabricated, and tested. It achieves a maximum power-added efficiency of 65%, and occupies an area of 0.20 by 0.36 inches. The circuit uses a low-reactance termination at the second harmonic and low-loss quasimonolithic circuitry. Intermodulation distortion performance at intermediate and high drive levels was found to be comparable to that of a class A amplifier. These results were obtained on the first fabrication run and with no circuit tuning.