Exploring Bias-Controlled Mode Reconfigurability in GaN-Based Doherty Power Amplifiers

In this work, we explore bias-controlled reconfigurable GaN-based Doherty Power Amplifiers (DPAs). By analyzing bias dependence at the device level and its impact at the circuit level, we show that carrier transport and voltage swing can be dynamically tuned to control amplifier performance. The bias dependence is validated through a 3.2–3.4 GHz DPA prototype, where bias tuning enables operation in four distinct modes: output power, gain, output back-off range, and back-off efficiency adjustment. The prototype achieves 37–42 dBm saturated output power, more than 1 dB gain enhancement, 6–10+ dB reconfigurable back-off range, and 45–65% back-off efficiency. The results demonstrate that bias control provides a systematic pathway for adaptive and versatile RF transmitters without requiring hardware changes.