A 6-/12-dB Back-off Multi-Mode GaN MMIC Doherty Power Amplifier for 5G Applications

This paper presents a multi-mode Doherty power amplifier (M-DPA) MMIC. By arranging the turn-on transitions of four parallel amplifiers, two carrier and two peaking amplifiers (2C2P) mode for 6 dB output power back-off (OBO) or one carrier and three peaking amplifiers (1C3P) mode for 12 dB OBO can be configured. The performances between efficiency and gain can be balanced according to the selected mode. For verification, the M-DPA MMIC was implemented using a 0.25 μm GaN-HEMT process for 5G NR applications (3.3-3.6 GHz band). At 3.55 GHz, the drain efficiencies (DEs) of 37.7 and 33.8% and power gains of 8.3 and 6.4 dB were obtained for the 2C2P mode at 37.0 dBm and for the 1C3P mode at 31.0 dBm, respectively.