Octave Band Linear MMIC Amplifier With +40-dBm OIP3 for High-Reliability Space Applications

Abstract

A systematic design procedure for highly linear and reliable amplifiers is proposed. The procedure deals with nonlinear modeling, junction temperature prediction methods, and circuit design techniques. A wideband linear monolithic microwave integrated circuit power amplifier based on a space-qualified GaAs process for C-band and extended C-band multicarrier satellite transponder is reported and described. The amplifier uses a bus-bar combiner in the power stage reaching an output power of 26.7 dBm at 1-dB compression point, with a small signal gain above 25 dB in the operation band between 3 and 6 GHz. The output third-order intercept point reaches levels above 40 dBm. The design ensures high reliability keeping the junction temperature below 112°C.Index Terms-Bus-bar combiner, C-band, high linearity, junction temperature, monolithic microwave integrated circuit (MMIC), nonlinear modeling, power amplifier. The authors are with the Microwaves