Efficiency improvement techniques for RF power amplifiers in deep submicron CMOS

Integration of RF power amplifier (PA) in CMOS technology can help to reduce total solution cost and achieve small form factor in modern communication systems. To improve overall efficiency of the power amplifier supporting modulated signals with very high peak-to-average power ratio (PAPR), new transmitter and PA architectures are being explored by researchers. This paper reviews some of our recent developments in CMOS based PA architectures including PWM based digital transmitter and outphasing power amplifier and presents a new multi-mode outphasing PA designed in 45 nm CMOS.