A 2.4GHz GaAs HBT stacked power amplifier with inductance compensation

Abstract

A stacked power amplifier (PA) using 2-µm GaAs HBT process is presented for 2.4GHz application. The stacked configuration can increase the output power by raising the supply voltage of the circuit. Additionally, a novel inter-stage matching technique with series RC is proposed to suppress the efficiency degradation caused by the parasitic capacitance. The measurement results show the compensation technique improves PAE by more than 6%, while the error vector magnitude (EVM) is enhanced. And the fabricated PA shows a gain of 23.7dB and a saturated output power of 32dBm with PAE of 50%, while the EVMs are lower than 3% up to 26dBm of OFDM/64QAM output power.