A 24-to-44 GHz Compact Linear 5G Power Amplifier with Open-Terminated Balun in 65nm Bulk CMOS

This paper presents a broadband linear CMOS power amplifier (PA) for mm-wave 5G applications. A broadband low-loss open-terminated balun is proposed for a PA output network with a smaller size. The PA fabricated using a 65-nm bulk CMOS process shows flat saturated output power, Psat, ranging from 17.5 to 19.5 dBm, within 2-dB difference, while achieving over 24.5% peak PAE for CW signals ranging from 24 to 44 GHz. It achieves a flat linear output power, P
linear
, of 10.4/11.6/10.9/8.8 dBm and a P
linear
PAE, PAE
linear
, of 6.24/8.94/7.9/5.1% with -25-dB rms EVM, EVM
rms
, and -23.3/-25.7/-25.9/-22.8-dBc ACPR at 24/28/39/44 GHz. Using the 5G NR FR2 64-QAM 8-CC×100-MHz OFDM signal (PAPR = 9.7 dB), broadband operation was demonstrated over 24–44 GHz covering n257-261 5G bands. It has a core size of 0.15 mm
²
.