A Broadband Three-Way Continuous-Mode Doherty Power Amplifier with Dual-Resonant Harmonic Injection Network

This paper presents a broadband three-way continuous-mode Doherty power amplifier (DPA) incorporating a multi-resonant harmonic injection network (HIN) for wideband efficiency enhancement. By optimizing the resonant frequencies and injection phases of the dual injection paths, the proposed harmonic injection structure overcomes the bandwidth limitations of conventional injection schemes, achieving high efficiency across a broad frequency range. Moreover, the incorporation of continuous-mode design methodology facilitates proper load modulation within the three-way DPA over the entire wideband operation. Measurement results demonstrate that, with the aid of the dual-HIN, the fabricated DPA exhibits robust broadband performance, achieving a drain efficiency (DE) of 62%–82% at saturation and 44%–60% at 10–11 dB output power back-off (OBO). The saturated output power ranges from 44.1 to 46.3 dBm.