Nonlinear Behaviour And Digital Phase Predistortion Of Outphasing Power Amplifiers

Conference: GeMIC 2008 - German Microwave Conference
03/10/2008 - 03/12/2008 at Hamburg-Harburg, Germany

Proceedings: GeMIC 2008

Pages: 4Language: englishTyp: PDF

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Authors:
Gerhard, W.; Knöchel, R. (University of Kiel, Microwave Laboratory, Kaiserstrasse 2, D-24143 Kiel, Germany)

Abstract:
The nonlinear behaviour of an outphasing 24W power amplifier (PA) for WCDMA basestation applications at 2.14GHz is investigated. For this purpose the nonlinear transfer characteristics are determined by measurements. Afterwards a digital phase-only predistortion is used to investigate the capability of a digital linearization approach. Two different test signals are applied to study the linearization performance. Firstly for a two-tone signal as a classical test signal an overall distortion level of -43dBc and secondly for an UMTS application utilizing a pseudo-noise (PN) modulated QPSK signal an adjacent channel power ratio (ACPR) of about -43dBc are achieved.