A 29-to-57GHz AM-PM compensated class-AB power amplifier for 5G phased arrays in 0.9V 28nm bulk CMOS

Abstract

This paper presents a 29-to-57GHz (65% BW) AM-PM compensated class-AB power amplifier tailored for 5G phased arrays. Designed in 0.9V 28nm CMOS without RF thick top metal, the PA achieves a Psat=15.1dBm±1.6dB and |AM-PM|<1° from 29-to-57GHz, with a peak PAE of 24.2%. Techniques are studied to realize the required load impedance and distortion cancellation over the wide band of operation, while allowing 2-way power combining to further increase the delivered POUT. The very low AM-PM distortion of the realized PA enables up to 10.1, 8.9, 5.9dBm average POUT while amplifying a 1.5, 3, 6Gb/s 64-QAM respectively at 34GHz with EVM/ACPR better than −25dBc/−30dBc, without any digital pre-distortion.