A fully integrated power amplifier with switched output network in GaAs HBT-HEMT process

This paper describes a fully integrated power amplifier (PA) with switched output network in 2 μm / 0.5 μm GaAs HBT-HEMT (BiFET) process. The proposed PA is designed using both HBT and PHEMT. The HBT is adopted for the PA and the bias circuit, while the PHEMT is adopted for the switched output network. By using the proposed method, the switchable PA demonstrates a power added efficiency (PAE) improvement of more than 20% at the low-power region. With dynamic current biasing (DCB) technique, the proposed PA can be operated both in high- and low-power mode with good PAE. At 2 GHz, the PA features an output P_1dB of 21.6 dBm, a peak PAE of 36.5% for the high-power mode, and a peak PAE of 33.8% with a output P_1dB of 7.9 dBm for the low-power mode.