ABSTRACT This paper presents a broadband and high‐efficiency Doherty power amplifier (DPA) based on the continuous inverse Class‐F topology for 5G and pre‐commercial 6G sub‐6 GHz applications. To overcome the inherent bandwidth limitations of traditional DPAs and maintain high efficiency at power back‐off, a continuous inverse Class‐F harmonic control strategy is proposed and implemented using a 0.25‐m gallium arsenide (GaAs) pHEMT process. A compact lumped‐element network is designed to achieve precise harmonic control, successfully shaping the voltage and current waveforms while minimizing the chip footprint. Post‐layout electromagnetic co‐simulations demonstrate that the proposed monolithic microwave integrated circuit (MMIC) operates robustly across the 5.0‐ to 6.0‐GHz frequency band. The amplifier delivers a saturated output power of 25.5–26.0 dBm with a saturated drain efficiency ranging from 33.8% to 40.7%. Furthermore, at 6‐dB output power back‐off (OBO), the drain efficiency is well‐maintained between 30.5% and 33.2%. With a compact overall chip dimension of 2.35 mm 2.3 mm, this work effectively balances the trade‐offs among bandwidth, efficiency, and size, demonstrating excellent potential for modern high peak‐to‐average power ratio (PAPR) communication systems.
Wang et al. (2026) studied this question.