High-Efficiency Gaas-Based Phemt C-Band Power Amplifier

A high-efficiency C-Band power amplifier design utilizing AlGaAs/InGaAs/GaAs pHEMT's is reported, On-wafer active loadpull power measurements at 4.5 GHz of a 0.25 mu m x 1.2 mm pHEMT exhibited an output power of 0.35 W and power-added efficiency of 79%. A single-stage MIC amplifier fabricated with a 2.8-mm-wide pHEMT resulted in P-out = 1.2 W and PAE = 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.