A 800-MHz power amplifier is designed using a 0.18-mu m RF CMOS process. The voltage-combining Method is used for power combining. A transmission line transformer on a printed circuit board (PCB) is designed as a power combiner. For the switching mode power amplifier, a cascaded class-D driver amplifier is proposed using a feedback resistor and a DC-blocking capacitor. The power amplifier has an output power of 32.9 dBm and a power-added efficiency of 60.25%. (c) 2007 Wiley Periodicals, Inc.