A 60-GHz Dual-Mode Class AB Power Ampli fier in 40-nm CMOS Dixian Zhao, Student Member , IEEE, and Patrick Reynaert ,S e n i o rM e m b e r ,I E EE

Abstract

A 60-GHz dual-mode power ampli fier (PA) is imple- mented in 40-nm bulk CMOS technology. To boost the ampli fier performance at millim eter-wave (mmWave) frequencies, a new transistor layout is proposed to minimize the device and intercon- nect parasitics while the neutralized amplifier stage is co-optimized with input transformer to improve t he power gain and stability. The transformer-based power-combining PA consists of two unit amplifiers, operating in Class AB for better back-off ef ficiency. To further reduce the power consu mption and hence extend battery lifetime, one unit PA is tuned off in low-power mode. A switch is used to short the output of this non-operating unit PA to reduce the combiner loss and improve the ef ficiency. The PA achieves a measured saturated output power of 17.0 dBm (12.1 dBm) and 1-dB compressed power of 13.8 dBm (9.1 dBm) in the high-pow er (low-power) mode. The power-added efficiencies (PAEs) at and are 30.3% and 21.6% respectively for the high-power mode. Compared to Class A, the PA operating in Class A B shows 5.3% improvement in measured PAE at with no compromise in linearity. The PA with the power combiner only occupies an active area of 0.074 mm .T h e reliability measu rements are also conducted and the PA has an estimated lifetime of 80613 hours.