Co-Designed High-Efficiency GaN Filter Power Amplifier

In this paper, we demonstrate a high-efficiency 4.7 GHz 4-W power amplifier with input and output matching networks designed as complex-impedance port filters, within a sub-6 GHz 5G band. The port impedances are determined by the load- and source-pull of a GaN HEMT for an efficiency-power tradeoff. The measured performance shows PAE=55% over a 9% fractional bandwidth, with 10 dB rejection at 4.5 and 5 GHz. Comparison with a cascaded PA-filter circuit shows 25% lower loss with a simultaneous 20% reduction in footprint.