A 3.4–3.5 GHz mode‐reconfigurable power amplifier with high efficiency with load mismatch and back‐off

Abstract

In this letter, a mode‐reconfigurable power amplifier (MRPA) is proposed to address the low efficiency in back‐off range and drastic impedance mismatch issues in 5G communications. The power amplifier based on a three‐branch reconfigurable quadrature coupler, capable of switching between two operating modes, Doherty and Balanced, while achieving excellent back‐off efficiency and resistance to load mismatch in 3.4–3.5 GHz band. The measured results of the proposed MRPA demonstrated a Psat of 43.5 dBm, a peak saturation drain efficiency (DE) of 64%–75%, and a 6 dB output back‐off DE of 48%–64%, and maintains a DE of more than 37% at voltage standing wave ratio = 2:1 mismatch level; at modulated wave amplification, the MRPA has an adjacent channel power leakage greater than 35 dBc in a 20 MHz 64‐QAM signal test and greater than 30 dBc in a 50 MHz 5G‐NR signal test.