A 1.9GHz 1W CMOS class E power amplifier for wireless communications

A CMOS implementation of a Class E power amplifier for wireless communications which operates in the GHz region is reported. The concept of mode-locking is introduced in which the amplifier acts as an oscillator whose output is forced to run at the input frequency. A prototype was built, which delivered over 1W of output power with 48% power added efficiency, centred at 1.9GHz using a 2V supply.