This paper presents a broadband high-efficiency power amplifier (PA) operating from 2.4 to 3.8 GHz, developed through a design strategy that exploits filter-based impedance matching networks. Instead of relying on conventional narrowband matching circuits, the proposed topology adopts a coupled-line structure derived from bandpass filter theory to achieve smooth impedance transformation, wideband performance, and inherent harmonic attenuation. Both the input and output matching networks are analytically synthesized to emulate bandpass characteristics, ensuring well-controlled impedance trajectories across the operating band. Employing a 10 W GaN HEMT transistor, the designed broadband PA achieves a nearly flat small gain of 11–16 dB, an output power of 38.7–40.9 dBm, and a drain efficiency up to 76.2 %. These results confirm the validity of integrating filter-inspired matching topologies as an effective and compact route toward next-generation broadband PAs. This research work directly supports SDG 9 (Industry, Innovation and Infrastructure) by enabling more capable and energy-efficient communication networks.

Broadband power amplifier; filter-based matching network; impedance synthesis; coupled-line structure; harmonic control; GaN HEMT; bandwidth enhancement; high efficiency