Title :
A Combined Series-Parallel Hybrid Envelope Amplifier for Envelope Tracking Mobile Terminal RF Power Amplifier Applications
Author :
Hassan, Muhammad ; Larson, Lawrence E. ; Leung, Vincent W. ; Asbeck, Peter M.
Author_Institution :
Univ. of California, San Diego, La Jolla, CA, USA
fDate :
5/1/2012 12:00:00 AM
Abstract :
An improved envelope amplifier architecture for envelope tracking RF power amplifiers is presented, consisting of two switching amplifiers and one linear amplifier. The first switching amplifier and the linear amplifier provide wideband and high-efficiency operation, while the second switching amplifier provides a reduced bandwidth variable supply to the linear amplifier to further reduce power loss. The first switching amplifier and the linear amplifier are fabricated together in a 150 nm CMOS process, while the second switching amplifier is external. Measurements show a maximum average efficiency of 82% for a 10 MHz LTE signal with a 6 dB PAPR at 29.7 dBm output power and an SFDR of 63 dBc for a single tone of 5 MHz driving an 8 Ω load.
Keywords :
CMOS analogue integrated circuits; HF amplifiers; power amplifiers; radiofrequency amplifiers; radiofrequency integrated circuits; wideband amplifiers; CMOS processing; LTE signal; PAPR; RF power amplifier application; SFDR; bandwidth variable supply reduction; combined series-parallel hybrid envelope amplifier architecture; efficiency 82 percent; envelope tracking mobile terminal; frequency 10 MHz; frequency 5 MHz; gain 6 dB; linear amplifier; maximum average efficiency; power loss reduction; resistance 8 ohm; size 150 nm; switching amplifier; wideband amplifier; Bandwidth; Cutoff frequency; Peak to average power ratio; Power generation; Radio frequency; Regulators; Switches; Envelope tracking (ET); long term evolution (LTE); power amplifier (PA); supply modulator;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2012.2184639
