3.0-3.6 GHz Wideband, over 46% Average Efficiency GaN Doherty Power Amplifier with Frequency Dependency Compensating Circuits

A wideband GaN Doherty power amplifier (DPA) for 4G/LTE-Advanced base stations is presented. To break the inherent narrow band limitation of conventional DPA, a frequency dependency compensating circuit and a modified λ/4 inverter incorporating package parasitic elements are proposed. Measured DPA achieves 45.9-50.2 % drain efficiency with -50 dBc ACLR at 3.0-3.6 GHz under 20 MHz LTE signal after digital pre-distortion (DPD), which is very suitable for multiband radio and carrier aggregation in 4G. The use of the wideband efficient GaN DPA can reduce the complexity and energy consumption of radio, which further helps reducing the total cost of ownership (TCO) of base stations.