Intermodulation Analysis of FDMA Satellite Systems Employing Compensated and Uncompensated TWT´s

Author

Saleh, Adel A M

Author_Institution

Bell Laboratories, Holmdel, NJ

Volume

30

Issue

5

fYear

1982

fDate

5/1/1982 12:00:00 AM

Firstpage

1233

Lastpage

1242

Abstract

In a frequency-division multiple-access (FDMA) satellite communication system, the output power of the TWT (or FET) amplifier is backed from saturation to reduce the intermodulation distortion caused by AM/AM and AM/PM nonlinearities. The required amount of backoff can be considerable, wasting valuable satellite power, unless some scheme is used to compensate for these nonlinearities. A comparative study is presented for the effectiveness of three types of predistortion compensators: (1) a cuber predistortion linearizer, which is the simplest to build; (2) an AM/PM equalizer; and (3) an ideal linearizer, which is quite difficult to realize in practice.

Keywords

frequency division multiplexing; multi-access systems; satellite relay systems; travelling wave tubes; AM/PM equalizer; TWT; cuber predistortion linearizer; frequency-division multiple-access; ideal linearizer; intermodulation distortion; predistortion compensators; satellite communication system; Artificial satellites; Digital communication; Equalizers; FETs; Frequency division multiaccess; Intermodulation distortion; Power amplifiers; Power generation; Predistortion; Satellite communication;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/TCOM.1982.1095568

Filename

1095568