Linearized high efficiency Class E power amplifier for wireless communications

Abstract

A linearized high efficiency Class E power amplifier for wireless communications is presented in this paper. It consists of a Class E power stage and a phase correcting feedback loop. The Class E power amplifier operating at 835 MHz delivers 443 mW to the load at a supply voltage of 2.4 V. The phase correcting feedback loop comprises novel limiting amplifier, phase detector and phase shifter. The phase correcting feedback reduces the 30/spl deg/ phase distortion of the Class E amplifier down to 4/spl deg/, resulting in a 20 dB reduction in adjacent channel interference. The total efficiency of the linearized Class E power amplifier is 65%.