Effect of envelope amplifier nonlinearities on the output spectrum of Envelope Tracking Power Amplifiers

Author

Hassan, Muhammad ; Larson, Lawrence E. ; Leung, Vincent W. ; Asbeck, Peter M.

Author_Institution

Univ. of California at San Diego, La Jolla, CA, USA

fYear

2012

fDate

16-18 Jan. 2012

Firstpage

187

Lastpage

190

Abstract

This paper examines the sources of Receive Band Noise (RxBN) in the Envelope Tracking Power Amplifier (ETPA) system. The Envelope Amplifier (EA) nonlinearity is found to be the dominant cause. The output spectrum of the ETPA is compared for the cases of highly linear class-A EA and nonlinear EA. To improve the out-of-band noise performance of the ETPA, Digital Pre-Distortion (DPD) on the envelope path is proposed. It is shown that the out-of-band noise is reduced by 10 dB at 100 MHz offset if a highly linear envelope amplifier is used.

Keywords

circuit noise; power amplifiers; envelope amplifier nonlinearities; envelope tracking power amplifiers; frequency 100 MHz; linear class-A envelope amplifier; nonlinear envelope amplifier; out-of-band noise; Linearity; Noise; OFDM; Power amplifiers; Power generation; Radio frequency; Switches; Amplitude modulator; envelope tracking; polar transmitter; power amplifiers; receive band noise;

fLanguage

English

Publisher

ieee

Conference_Titel

Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2012 IEEE 12th Topical Meeting on

Conference_Location

Santa Clara, CA

Print_ISBN

978-1-4577-1317-0

Type

conf

DOI

10.1109/SiRF.2012.6160129

Filename

6160129