Optimal-filter approach for nonlinear power amplifier modeling and equalization

Author

Silva, C.P. ; Clark, C.J. ; Moulthrop, A.A. ; Muha, M.S.

Author_Institution

Aerosp. Corp., El Segundo, CA, USA

Volume

1

fYear

2000

fDate

11-16 June 2000

Firstpage

437

Abstract

This paper presents an optimal-filter method for application to the equalization and modeling of nonlinear power amplifiers. The method uses auto-spectral and cross-spectral densities of measured amplifier input/output time-domain waveforms. An optimal filter response is calculated which best approximates a given nonlinearity as quantified by a new and useful linear coherence function metric. This response can in turn be used to determine optimal equalizer responses. It is also shown that by adding an optimal filter to the output of the standard two-box amplifier nonlinear model, waveform accuracy can be improved by 3.5 dB. The approach is applied to a 20-GHz traveling-wave tube amplifier using 9.6 Gbps 16-APK input signals.

Keywords

equalisers; power amplifiers; travelling wave amplifiers; 20 GHz; 9.6 Gbit/s; APK signal; auto-spectral density; cross-spectral density; equalization; linear coherence function; nonlinear power amplifier; optimal filter; time domain waveform; traveling wave tube amplifier; two-box model; Baseband; Constellation diagram; Equalizers; Frequency response; Hardware; Nonlinear distortion; Nonlinear filters; Nonlinear systems; Power amplifiers; Power system modeling;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest. 2000 IEEE MTT-S International

Conference_Location

Boston, MA, USA

ISSN

0149-645X

Print_ISBN

0-7803-5687-X

Type

conf

DOI

10.1109/MWSYM.2000.861058

Filename

861058