The main bottleneck in the design of RF to mm-wave transceiver systems based on CMOS technology is a high performance power amplifier (PA). Nanoscale CMOS technology suitable for RF to mm-wave implementation suffers from low breakdown voltages, which makes the design of high-power and high-efficiency PAs very challenging. CMOS SOI technology has been shown to overcome some of these challenges. In this short course we will discuss the basics of CMOS PA design and review various design techniques to achieve high power and high efficiency PAs.