HIGH-EFFICIENCY GAAS-BASED PHEMT C-BAND POWER-AMPLIFIER

A high-efficiency C-Band power amplifier design utilizing AlGaAs/InGaA s/GaAs pHEMT's is reported, On-wafer active loadpull power measurement s at 4.5 GHz of a 0.25 mu m x 1.2 mm pHEMT exhibited an output power o f 0.35 W and power-added efficiency of 79%. A single-stage MIC amplifi er fabricated with a 2.8-mm-wide pHEMT resulted in P-out = 1.2 W and P AE = 74% at 4 GHz, These results demonstrate the potential of pHEMT's to significantly improve the efficiency performance of microwave solid state power amplifiers compared to present MESFET designs.