A ku-band phemt mmic high power amplifier design

Abstract

Power amplifiers are regarded as the one of the most important part of the radar and communication systems. In order to satisfy the system specifications, the power amplifiers must provide high output power and high efficiency at the same time. AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistors (PHEMT) provides significant advantages offering high output power and high gain at RF and microwave frequencies. Considering the electrical performance, cost and the reliability issues, pHEMT monolithic microwave integrated circuit (MMIC) high power amplifiers are one of the best alternatives at Ku-band frequencies (12-18 GHz portion of the electromagnetic spectrum in the microwave range of frequencies). In this thesis, a three-stage AlGaAs/InGaAs/GaAs pHEMT MMIC high power amplifier is developed which operates between 16-17.5 GHz. Based on 0.25 µm gate-length pHEMT process, the MMIC is fabricated on 4-mil thick wafer with the size of 5.5 x 5.7 mm2 . Under 8V drain voltage operation, 26.5-24 dB small signal gain, 10-W (40 dBm) continuous-wave mode output power at 3 dB compression with %25-30 drain efficiency is achieved when the base temperature is 85◦C.