Design and linearization of Class-E power amplifier for non-constant envelope modulation

This paper presents design and linearization techniques for a highly efficient but nonlinear class-E power amplifier (PA) applied to linear RF transmitters. A predistorted envelope modulation scheme is proposed to linearize the class-E PA. To accomplish this scheme, the class-E PA is designed with consideration of finite DC-feed inductance for wide supply-voltage modulation bandwidth. In addition, a digital envelope predistorter (DEP) is designed to provide the predistored envelope modulation for both RF-input and supply-voltage signals fed to the class-E PA. A cdma2000 1x transmitter incorporating such a Class-E PA and a DEP has been implemented to serve as an evidence for the simultaneous achievement of high efficiency and high linearity.