A high-efficiency 5G K/Ka-band stacked power amplifier in 45nm CMOS SOI process supporting 9Gb/s 64-QAM modulation with 22.4% average PAE

This paper presents a 3-FET stacked K/Ka-band class-AB power amplifier (PA) implemented in the GLOBALFOUNDRIES 45nm SOI process that is particularly optimized for future high-performance energy-efficient 5G mm-Wave transceiver front-ends. With a 2.9V power supply, the PA achieves 13.1dB power gain and a saturated output power (P
sat
) of 16.2dBm with a maximum power-added efficiency (PAE) of 41.5% at 24GHz continuous-wave (CW). The output 1dB compression point (P1dB) is 14.2dBm with 37.4% PAE. The Psat 1dB frequency range is 18GHz–29GHz. With a 9Gb/s 64-QAM modulated signal, 22.4% average PAE and −25.1dB EVM are achieved with 9.9dBm average output power. With a 960Mb/s 64-QAM signal, 22.5% average PAE, −29.6dB EVM, and −30.5dBc ACLR are achieved with 9.5dBm average output power. No digital pre-distortion is employed in both modulation tests. The total PA area is only 550μm × 750μm.