A Sub-6GHz Compact GaN MMIC Doherty PA with a 49.5% 6dB Back-Off PAE for 5G Communications

This paper presents a sub-6 GHz MMIC Doherty power amplifier (DPA) for 5G communication applications based on a 0.25-µm GaN HEMT process. The impedance inverter of the DPA is realized by combining a compact transmission line network with two shunt capacitors. Also, the ratio of power cells in the main and auxiliary amplifiers is optimized to achieve a high efficiency in output power back-off. The measured peak output power and P1dB are 38.7 and 32.1 dBm, respectively at 5.9 GHz. The power-added-efficiency (PAE) at a 6-dB output power back-off is up to 49.5%.