A novel method for extending the output power back-off range of an asymmetrical Doherty power amplifier

Abstract

A novel method is proposed to extend the output power back-off (OPBO) range of the Doherty power amplifier (DPA). This study reveals that the OPBO range of the DPA can be extended by tuning the output impedance of the peaking stage away from infinity and changing the phase delay of the output matching network of the carrier power amplifier. Based on this theory, a large-OPBO-range high-efficiency asymmetrical DPA working band from 1.55 to 2.2 GHz (35% relative bandwidth) is designed to verify the proposed method. Experimental results show that the DPA operates from 1.6 to 2.1 GHz. The range of the measured efficiency is 42.2%–52.1% in the OPBO state and 47%–62.7% in the saturation state. The OPBO range is 11.1–13.2 dB.

Keywords

Doherty power amplifier (DPA) / Output power back-off (OPBO) / Output impedance / Network phase

RIGHTS & PERMISSIONS

2023 Zhejiang University Press