Continuous-Time Model Identification of RF Power Amplifiers

Mourad Djamai, Smail Bachir, Claude Duvanaud


The Radio Frequency Power Amplifier is the major source of the nonlinear distortion which affect the signal modulated in the Radiocommunication transmission system. To analyse and treat the distortion caused to the amplified signal, this paper presents the parameters estimation of a behavioral model. Based on baseband signals, this model includes a polynomial function representing AM/AM and AM/PM characteristics in addition with MIMO continuous filter to describe the PA dynamics. Using the baseband input and output data, model parameters are obtained recursively by an iterative identification algorithm based on Output Error method. Initialization and excitation problems are resolved by an association of a new technique using initial values extraction with a multi-level binary sequence input exciting all PA dynamics. Finally, the proposed estimation method is tested and validated on experimental data.

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S. C. Cripps, Advanced Techniques in RF power Amplifier Design, Artech House, Boston 2002.

P. B. kennington, High-linearity RF Amplifier Design, Artech House, Boston 2000.

N. B. Carvalho and J. C. Pedro, A Comprehensive explanation of distortion sideband asymmetries, in IEEE Trans. Micro. Theo. Tech., VOL. 50, pp. 2090-2101, 2002.

C. J. Clark, G. Chrisikos, M. S. Muha, A. A. Moulthrop and C. P. Silva, Time-domain envelope measurement technique with application to wideband power amplifier modeling, in IEEE Trans. Microwave Theory Tech. VOL. 46, NO. 12, pp. 2531-2540, Dec. 1998.

M. Isakson, D. Wisell and D. Ronnow, A Comparative Analysis of behavioral Models for RF Power Amplifiers, in IEEE Trans. Microwave Theory Tech., VOL. 54, No. 1, pp. 348-359, Junuary 2006.

G. Tong Zhou and Raviv Raich, Spectral Analysis of Polynomial Nonlinearity with Applications to RF Power Amplifiers, EURASIP Journal on Applied Signal Processing, Issue 12, pp. 1831-1840. 2004.

T. Liu, S. Boumaiza, and F. M. Ghannouchi, Dynamic Behavioral modeling of 3G Power Amplifiers Using real-Valued Time-Delay Neural Networks, in IEEE Trans. Microwave Theory Tech., VOL. 52, No. 3, pp. 1025-1033, March 2004.

J. Xu, M. C. E. Yagoub, R. Ding and Q. J. Zhang, Neural-Based Dynamic Modeling of Nonlinear Microwave Circuits, in IEEE Trans. Microwave Theory Tech., VOL. 50, No. 12, pp. 2769-2780, December 2002.

H. Hyunchui, M. D. Mckinley and J.S. Kenney, Quantifying Memory Effects in RF Power Amplifiers, in IEEE Trans. Microwave Theory Tech., VOL. 50, No. 12, pp. 2843-2849, December 2002.

H. Hyunchui, M. D. Mckinley and J. S. Kenney, Behavioral Modeling of Nonlinear RF Power Amplifiers Considering Memory Effects, in IEEE Trans. Microwave Theory Tech., VOL. 51, pp. 2495-2503, December 2003.

F. Launay, Y. Wang, S. Toutain, D. Barataud, J. M. Nebus and R. Quere, Nonlinear amplifier modeling taking into account HF memory frequency, in MTT-S Int. Micro. Symposium Digest, VOL. 02, pp. 865-868, 2002.

A. Zhu, M. Wren, T. J. Brazil, An Efficient Volterra-based Behavioral Model for Wideband RF Power Amplifiers, MTT-S Int. Microwave Symposium Digest, VOL. 02, pp. 865- 868, 2003.

H. Unbehauen and G.P. Rao, A review of identification in continuous-time systems, Annual Reviews in Control 22, pp. 145-171, 1998.

H. Unbehauen and G.P. Rao, Identification of continuous systems, Systems and control series. North-Holland, 1987.

P. Young, Parameter estimation for continuous-time models - a survey, Automatica, VOL. 17, No. 01, pp. 23-39, 1981.

L. Ljung, System identification: Theory for the user, Prentice Hall, USA, 1987.

J. Richalet, A. Rault and R. Pouliquen, Identification des processus par la m`ethode du mod`ele, Gordon & Breach, Th´erie des syst`emes, No . 04, 1971.

J. C. Trigeassou, Recherche de mod`eles exp´erimentaux assist´ee par ordinateur, Technique et Documentation Lavoisier, Paris, 1988.

M. Djamai, S. Bachir and C. Duvanaud, Behavioral modeling and digital predistortion of RF power amplifiers, Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMiC), Portugal, January 2006.

M. Djamai, E. Tohme, S. Bachir and R. Ouvrard, Conyinuous-Time Model Identification Using Reinitialized Partial Moments - Application To Pwer Amplifier Modeling, IFAC Symposium on System Identification SYSID'06, Australia, 2006.

D. W. Marquardt, An Algorithm for least-squares estimation of non-linear parameters, Soc. Indust. Appl. Math, VOL. 11, NO. 2, pp. 431-441, 1963.

M. S. Muha, C. J. Clark, Validation of power Amplifier Nonlinear Block Models, MTT-S Int. Microwave Symposium Digest, pp. 759-762, 1999.

J. C. Trigeassou, T. Poinot and S. Bachir , M´ethodes de commande des machines ´electriques, Chapter 7 : Estimation param´etrique pour la connaissance et le diagnostic des machines ´electriques, pp. 215-251, Trait´e EGEN - S´erie G. Electrique, Herm`es Publications 2003.


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