A class‐E CMOS RF power amplifier with cascaded class‐D driver amplifier

A 800-MHz power amplifier is designed using a 0.18-μm 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%. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 470–473, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23106