A 140 W Integrated GaN Doherty Power Amplifier Module Based on a Triple-tuned Design Method for 5G Massive-MIMO Base-Stations

This paper presents a two-stage Doherty power amplifier (DPA) module designed for high-efficiency operation in 5G massive-MIMO base transceiver systems (BTSs). The DPA's high performance is achieved through a simplified load network consisting of only a post-matching network and two L-section networks which reduce insertion loss, circuit area, and production cost. The load network employs an analytical triple-tuned approach that defines three key design parameters: the relative phase and group delay of transistor output currents, and the load admittance at the combining junction. Implemented in a 0.25 μm GaN-HEMT process with an area of 13 × 10 mm2, the module demonstrates an average output power of 44 dBm and a high power-added efficiency of 49.1 – 50.8% at the frequency range of 3.4 – 3.8 GHz. When linearized using memory-polynomial digital pre-distortion under 5G New Radio (NR) excitation, it maintains an adjacent channel leakage ratio (ACLR) better than -48.6 dBc.