A 3.9-GHz-Band Outphasing Power Amplifier with Compact Combiner Based on Dual-Power-Level Design for Wide-Dynamic-Range Operation

An outphasing power amplifier with a compact combiner has been developed for recent and future wireless communication systems. The combiner could be successfully shrunk by applying a series-load-compensation connection scheme. In addition, a dual-power-level design was applied for the power amplifier to increase the dynamic range of its high-efficiency power. A fabricated GaN HEMT outphasing power amplifier exhibited a peak drain efficiency of 77% with a saturation power of 37dBm at 3.92 GHz. In addition, a drain efficiency of more than 50% was maintained within an output back-off of 7 dB.