Microwave Power Applications of GalIium Arsenide Heterojunction Bipolar Transistors

Abstract

applications have shown marked improvements in output power and power added efficiency (PAE) during recent years (1,2]. HBTs exhibiting efficiencies in excess of 50% and power densities up to 4 waWmm (CW) at X-band have been reported (2). Under pulsed operation, an increase in output power by -3 dB has been observed. As a consequence of these impressive results, HBTs are currently being considered as replacements for MESFETs in the next generation solid state power amplifiers requiring increased power and efficiency from modules ofthe same size as those in use today. This paper will discuss electrical and thermal design of power HBTs and present the performance of a very high efficiency 8-14GH2, 1 W HBT amplifier [3]. This amplifier represents the state-of-the-art in PAE over this band. GaAslAIGaAs heterojunction bipolar transistors (HBTs) designed for microwave power