Wideband GaN digital class-E Doherty PA for sub-6 GHz 5G applications

This work presents a GaN-based digital class-E Doherty power amplifier module for the 5G FR1 frequency band. The design integrates two identical class-E MMICs, driven by digital pulse-width-modulated signals, in a two-way wideband Doherty configuration. This configuration is co-optimized together with the class-E components of the amplifiers to achieve high efficiency over an extended output back-off range of up to 9 dB. At 7.5 dB back-off, the measured final-stage drain efficiency reaches 68% with a 3.4 GHz single-tone input. Across the (3.2–3.6) GHz band, the prototype maintains a minimum efficiency of 52% at 9 dB output power back-off, with a maximum saturated output power of 32.8 dBm. At 3.3 GHz, the module achieves efficiencies of 60% and 59% for 20 and 100 MHz digital OFDM signals with 9 dB peak-to-average power ratio, respectively.