GaN HEMT based class-F power amplifier with broad bandwidth and high efficiency

This paper presents the design and realization of a highly efficient broadband class-F power amplifier (PA) with a multi-harmonic controlled output network. Optimum performance in terms of bandwidth and efficiency is targeted over the frequency band 1.1-2.1 GHz. The design is developed in the Keysight Advanced Design System (ADS) environment and verified experimentally through small- and large-signal characterization. The optimum load and source impedances are determined by performing load-pull and source-pull simulations. The output matching network is designed including harmonic resonators up to the fourth harmonic. In order to achieve broadband operation, the load impedances at harmonics are optimized. The realized PA exhibits state-of-the-art performance, with a power gain of 10-15 dB, a saturated drain efficiency of 60-73% and 10 W output power throughout the selected frequency band (1.1-2.1 GHz). Experimental results show remarkably good agreement with the simulation results.