A 28-GHz Highly Efficient CMOS Power Amplifier Using a Compact Symmetrical 8-Way Parallel-Parallel Power Combiner with IMD3 Cancellation Method

This paper presents a linear CMOS power amplifier (PA) for mm-wave 5G applications. A compact 8-way parallel-parallel power combiner is proposed to increase Pout with low loss and symmetrical phase/amplitude. The IMD3 cancellation method is presented in this work to obtain a high linear P
_OUT
with high PAE. The PA in 65-nm CMOS shows a 23.2dBm P
_OUT
with 33.5% PAE for CW signals at 28GHz. It achieves the highest linear PAE of 17.6% at an average P
_OUT
of 18.02dBm with -31.2dB EVM and -30dBc ACPR supporting a 256-QAM 100MSym/s signal at 28GHz.