High-efficiency GaAs-based pHEMT C-band power amplifier

A high-efficiency C-Band power amplifier design utilizing AIGaAs/InGaAs/GaAs pHEMT's is reported. On-wafer active loadpull power measurements at 4.5 GHz of a 0.25μm x 1.2 mm pHEMT exhibited an output power of 0.35 W and power-added efficiency of 79%. A singlestage MIC amplifier fabricated with a 2.8-mm-wide pHEMT resulted in P/sub 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.