Abstract
This paper addresses the state-of-the-art in microwave and millimetre-wave power transistor technology. The relative performance of microwave power transistor technology from 1 GHz to 60 GHz is reviewed. The fundamental technological drivers in the design of microwave compound semiconductor power transistors are discussed as the basis for developing optimum designs. A new high yield power GaAs pHEMT process is described and the application of this technology to multi-carrier microwave power amplifiers is discussed, achieving state-of-the-art performance, with output powers of up to 120 W with 70% efficiency at 2.1 GHz.