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

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.