500 W Three-way GaN Doherty Power Amplifier for Sub-6 GHz 5G New Radio Base Transceiver Systems

This paper presents a three-way Doherty power amplifier (DPA) using a broadband load network for the wideband 5G new radio (NR) signal. The broadband load network was proposed for bandwidth extension using a 180° quasi-lumped transmission line (TL) including the internal components of a high-power packaged transistor and the optimized impedance transformation ratio (ITR) for each section of the load network. The proposed three-way DPA was designed using 200 W GaN-HEMTs for the carrier and two peaking amplifiers at a frequency range from 3.6 to 3.8 GHz. For a two-carrier 5G NR signal with a signal bandwidth of 200 MHz and a peak-to-average power ratio (PAPR) of 9.5 dB, the implemented DPA exhibited a drain efficiency (DE) of 37.7% and an adjacent channel leakage power ratio (ACLR) of -44.2 dBc after a digital pre-distortion (DPD) at an average output power of 47.5 dBm.