Rational function based predistorter for traveling wave tube amplifiers

Author

Mahil, Sukhdeep ; Sesay, Abu B.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Calgary, Alta., Canada

Volume

51

Issue

1

fYear

2005

fDate

3/1/2005 12:00:00 AM

Firstpage

77

Lastpage

83

Abstract

A new scheme for the compensation of traveling wave tube amplifier nonlinearities is proposed and analyzed in this paper. The approach is based on rational function models of the amplifier AM-AM and AM-PM conversions. Amplitude and phase predistortion are performed separately. The phase predistortion is a function of the output of the amplitude predistortion part of the predistorter, instead of the input signal amplitude of the predistorter. Computer simulations reveal an improved performance compared to published techniques and suggest that with the proposed technique the transmit power amplifier can operate far into its nonlinear region. The transfer characteristics of the cascade of the amplifier and the proposed predistorter match the optimum transfer characteristics of a saturating device.

Keywords

error statistics; power amplifiers; rational functions; travelling wave amplifiers; amplifier conversions; amplitude-phase predistortion; bit error rate; optimum transfer characteristics; rational function based predistorter; transfer characteristics; transmit power amplifier; traveling wave tube amplifiers; Bandwidth; Bit error rate; Constellation diagram; Interference; Nonlinear distortion; Polynomials; Power amplifiers; Predistortion; Quadrature amplitude modulation; Transmitters; Bit error rate; power amplifier; predistortion; rational function;

fLanguage

English

Journal_Title

Broadcasting, IEEE Transactions on

Publisher

ieee

ISSN

0018-9316

Type

jour

DOI

10.1109/TBC.2004.842519

Filename

1406155