Broadband GaN MMIC Doherty Power Amplifier Using Continuous-Mode Combining for 5G Sub-6 GHz Applications

This article presents a broadband fully integrated Doherty power amplifier (DPA) using continuous-mode combining load. It is illustrated that the impedance condition in back-off and saturation for operation can be achieved with simple inverter network (IIN) realized lumped components gallium nitride (GaN) monolithic microwave circuits (MMICs). A DPA was designed fabricated 250-nm GaN process to validate proposed architecture design methodology. The chip attains around 8 W saturated from 4.1 5.6 GHz. About 38.5%–46.5% drain efficiencies are at 6-dB output within entire band. When driven by 100-MHz OFDM signal 6.5-dB peak-to-average ratio (PAPR), achieves better than −45-dBc adjacent channel leakage (ACLR) higher 38% average efficiency 4.4 5.2 GHz after digital predistortion.