A beamforming phased-array has become an indispensable configuration in 5 G new-radio (NR) frequency-range-2 (FR2) cellular communications to boost an equivalent isotropic radiated power. In order to miniaturize the beamforming phased array with high output power, a beamforming transceiver IC should be highly integrated with multiple channels. Silicon-based power amplifiers (PAs) have been widely used to increase the degree of integration with transceiver ICS; however, they still suffer from low power added efficiencies at an average output power (PAEavg ) due to large peak-to-average power ratios (PAPRs) of ~10 dB[1–3]. In order to improve the PAEavg of the PA over the mm-wave frequency range, Doherty PAs have been considered as good candidates [4–6]. Nevertheless, the Doherty PA faces several challenges for high integration due to the following reasons: complex structure and bulky size. Especially, the extensive size immediately increases costs of a beamforming transceiver IC.

https://ieeexplore.ieee.org/document/10454406