A 3.4-4.1GHz Broadband GaN Doherty Power Amplifier Module for 5G massive-MIMO Base-Stations

This paper presents a 3.4-4.1 GHz broadband two-stage GaN Doherty Power Amplifier (DPA) Module for 5G massive MIMO Base-Stations. In order to achieve high efficiency, broadband and compact DPA module in a multi-chip configuration, new design method to realize an impedance inverting network in DPA by Tee-type transmission line network with parasitic capacitance absorption even in the presence of series components between auxiliary power amplifier and combining node is proposed. The proposed method is applied to a compact two-stage GaN DPA module with effective area of 76mm2. Measurements showed that the DPA module achieved PAE of 42.0-44.6%, gain of 28.6-31.0dB and Pout of 40.3-40.8dBm over 700MHz for 3.4-4.1GHz with ACLR less than -47dBc under 20MHz modulation signal with PAPR of 7.5dB, after DPD. The proposed DPA module has the most wideband characteristic ever reported among DPAs in 3-4GHz band, demonstrating that the proposed design method is effective.