Title :
Full Feedforward of the Output Voltage to Improve Efficiency for Envelope-Tracking Power Supply Using Switch-Linear Hybrid Configuration
Author :
Xi, Huan ; Jin, Qian ; Ruan, Xinbo ; Xiong, Xiaoling
Author_Institution :
Aero-Power Sci-tech Center, Nanjing Univ. of Aeronaut. & Astronaut., Nanjing, China
Abstract :
A synchronous rectification buck converter in parallel with a Class AB linear amplifier is presented in this paper to construct an envelope-tracking (ET) power supply. To eliminate the influences of the output voltage on the linear amplifier output current, a full feedforward of the output-voltage scheme with two feedforward terms is proposed in this paper, which can counteract all the two load admittances of the linear amplifier, respectively, consequently decreasing the linear amplifier output current substantially. An ET power supply prototype with 100-kHz sine-wave tracking, 5-15 V output voltage, and 75-W-peak output power is fabricated and tested in the lab. The experimental results are well in agreement with the theoretical analyses, and the system efficiency is improved significantly.
Keywords :
feedforward amplifiers; power convertors; power supply circuits; ET power supply prototype; class AB linear amplifier; efficiency improvement; envelope-tracking power supply; frequency 100 kHz; full feedforward; load admittances; output-voltage scheme; power 75 W; sine-wave tracking; switch-linear hybrid configuration; synchronous rectification buck converter; voltage 5 V to 15 V; Power supplies; Pulse width modulation; Switches; Switching converters; Switching frequency; Voltage control; Envelope tracking (ET); feedforward; power amplifier (PA); switch-linear hybrid configuration;
Journal_Title :
Power Electronics, IEEE Transactions on
DOI :
10.1109/TPEL.2012.2200109
