A 28 GHz 22FDX® PA with 31.5 % Peak PAE and Output Power of 21 dBm in CW, 18.5 dBm in QPSK, and 12.5 dBm in 64QAM

Abstract

A 22nm FD-SOI Power Amplifier (PA) for 5G communication at 28 GHz is demonstrated. A dual-stage approach together with stacking techniques and optimized transistor-interconnection layout is used to achieve a measured peak PAE above 31% with an output power of 21.0 dBm. Besides output power and PAE, the PA demonstrated 12.5 dBm at −28 dB EVM with 64-QAM CF -OFDM 5G modulated signal and 18.5 dBm with DFT-s-OFDM QPSK modulated signal at −19 dB ACLR with 100-MHz bandwidth with a linear PAE of 20%. To the best of the authors knowledge, the presented PA shows the highest linear power and efficiency with QPSK while its 64-QAM modulated output power outperforms by 1 dB the state of the art while also reducing the EVM by 1 dB, when compared against 2-stage PA silicon implementations. Finally, an output-power degradation below 0.05 dB after 66 hours of stress at 21 dBm power level has been shown to demonstrate excellent reliability.