Phase-correcting feedback system for class E power amplifier

A phase-correcting feedback system which reduces the AM-to-PM distortion of Class E power amplifiers for wireless communication is presented in this paper. It comprises a novel limiting amplifier, a phase detector, and a phase shifter all operating at 835 MHz. The phase-correcting feedback together with a Class E power amplifier were fabricated in a 0.8-/spl mu/m GaAs MESFET process. The limiting amplifier has a phase error less than 2.5/spl deg/. The phase detector and phase shifter have a sensitivity of 10 mV/degree and 80/spl deg//V, respectively. The Class E power amplifier delivers 26.5 dBm to the load with a power added efficiency of 67%. The phase correcting feedback system reduces the 30/spl deg/ phase distortion of the Class E amplifier down to 4/spl deg/, and its total power dissipation is 21.5 mW.