Broadband Integrated Doherty Power Amplifier Module Using Advanced GaN-on-Si HEMT Technology for 5G mMIMO Base Stations

In this paper, a broadband integrated GaN Doherty power amplifier (PA) module for 5G massive MIMO base stations is reported. Benefiting from the dual-driver Doherty structure and the optimal biasing scheme, the lineup efficiency has been boosted without compromising the linearity. The adopted passive networks, including the combiner, interstage and input matching network, have been developed for broadband operation and eventually have been miniaturized into 12 × 8 mm2 laminate. The PA module features compact dimensions and lightweight characteristics for the 5 G base station scenario. It achieves an efficiency higher than 45.8% and a gain of more than 31 dB across the 3.6-4.0 GHz band under a 100-MHz LTE signal with 8-W average output power. Linearized adjacent channel power ratio of -54.5 and -50.5 dBc, is achieved through digital pre-distortion for 20- and 100-MHz signals, respectively.