Inverse-Class-F PA Design with Dual-TL Matching Network

This paper proposes an inverse-Class-F GaN HEMT power amplifier (PA) based on a dual transmission line (DTL) output matching network, addressing the limitations of conventional harmonic tuning circuits in terms of high complexity and restricted harmonic suppression capability. Through theoretical derivation and simulation verification, a 2.4 GHz high-efficiency PA is designed, where the DTL structure functions as a quarter-wavelength impedance transformer at the fundamental frequency while achieving up to 6th-order harmonic suppression. Implemented with Cree’s CGH40025F transistor, the simulated results demonstrate a power-added efficiency (PAE) of $83.7 \%$ at 43.5 dBm saturated output power, showing significant efficiency improvement over traditional open/short-stub designs and doubling the harmonic suppression capability. This compact solution provides high-efficiency power amplification for 5G small cells and satellite communication terminals.