High efficiency small size 6 W class AB X-band power amplifier module using a novel MBE GaAs FET

A high-efficiency, 7.2 mm GaAs power FET is described that uses a novel doping profile grown by molecular-beam epitaxy. This FET has achieved greater than 7-dB gain and 35.3-dBm power operating in class AB mode with a power-added-efficiency (PAE) of 40% at 10.2 GHz. Extremely compact single- and two-stage balanced amplifier modules were developed achieving power, gain, and PAEs of 37.7 dBm, 6.7 dB, and 34.8% for the single stage and 37.7 dBm, 15.1 dB, and 33.1% for the double stage at 1- and 2-dB gain compression points, respectively, across the 9.2-10.2-GHz band with good gain flatness and output return loss. The total two-stage amplifier was realized on a carrier measuring only 0.700 in. by 0.280 in. by using high-dielectric-constant substrates for all the matching circuits. The values for the PAE remained relatively constant with flange temperatures up to 75 degrees C.<>