A 13-GHz Harmonic Tuned Asymmetric Doherty Power Amplifier with Compact and Precise Matching Network for 6G Application

This paper presents a 13-GHz 2-stage asymmetric Doherty power amplifier (DPA) with improved power back-off (PBO) efficiency for 6G application. In order to achieve the improved efficiency and precise impedance matching, the second harmonics are directly terminated and the transistor core is re-modeled along with a routing line. A modified power divider and asymmetric input/output matching networks are designed for 8 dB PBO. The designed PA is implemented in a GaAs pHEMT process with a compact chip size of 3.64 × 2.34 mm². From continuous wave measurement, the PA achieves a maximum output power of 27.6 dBm with a peak and a back-off power-added efficiency (PAE) of 43.0% and 28.3% at 13.2 GHz. From applying a 100 MHz 64-QAM 5G NR signal, the PA shows an average power of 19.6 dBm with a PAE of 28.2% and an ACLR of -44.5 dBc by using DPD.