A 3.1-GHz Class-F Power Amplifier With 82% Power-Added-Efficiency

This letter presents the first high-frequency, multi-harmonic-controlled (> 3), Class-F power amplifier (PA) implemented with a packaged GaN transistor. For PA design at high frequencies, parasitics of a packaged transistor significantly increase the difficulty of harmonic manipulation, compared to low-frequency cases. To overcome this issue, we propose a novel design methodology based on a three-stage, low-pass, output matching network, which is realized with transmission lines. This network provides optimal fundamental impedance and allows harmonic control up to the fourth order to enable an efficient Class-F behavior. The implemented PA exhibits a state-of-the-art performance at 3.1 GHz with a 82% PAE, 15 dB gain, and 10 W output power, indicating a clear advantage of this method over the conventional ones with extra parasitic compensators.