Memory effect evaluation and predistortion of power amplifiers

This paper introduces the envelope model reference adaptive control construct to digital predistortion of RF power amplifiers. It is used to formulate a block level predistortion algorithm that compensates for the both memoryless compression characteristics and deterministic memory effects. An iterative technique of successive approximations is used to obtain the memory effect inverse function. The algorithm is applied to two amplifiers and convergence is demonstrated. Qualitative results (instantaneous input/output plots) and quantitative results (the sequence and ensemble RMS error over the iteration sequence) are presented.

[1]  J. Brinkhoff,et al.  Charge trapping and intermodulation in HEMTs , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[2]  G. P. Gualtieri,et al.  A modified Volterra series approach for nonlinear dynamic systems modeling , 2002 .

[3]  J. Rathmell,et al.  Contribution of self heating to intermodulation in FETs , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[4]  William R. Panton,et al.  Effects of nonlinear distortion on CDMA communication systems , 1996, IMS 1996.

[5]  D. Barataud,et al.  An improved behavioral modeling technique for high power amplifiers with memory , 2001, 2001 IEEE MTT-S International Microwave Sympsoium Digest (Cat. No.01CH37157).

[6]  Y. D. Landau,et al.  Adaptive control: The model reference approach , 1979, IEEE Transactions on Systems, Man, and Cybernetics.

[7]  T. Rahkonen,et al.  Measurement technique for characterizing memory effects in RF power amplifiers , 2000, RAWCON 2000. 2000 IEEE Radio and Wireless Conference (Cat. No.00EX404).

[8]  L. Larson,et al.  Envelope tracking power amplifier with pre-distortion linearization for WLAN 802.11g , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[9]  G. Baudoin,et al.  EER architecture specifications for OFDM transmitter using a class E amplifier , 2004, IEEE Microwave and Wireless Components Letters.

[10]  A. Zinober,et al.  Adaptive Control: the Model Reference Approach , 1980 .

[11]  J. S. Kenney,et al.  Quantifying memory effects in RF power amplifiers , 2002 .

[12]  P. Draxler,et al.  Time domain characterization of power amplifiers with memory effects , 2003, IEEE MTT-S International Microwave Symposium Digest, 2003.

[13]  L.E. Larson,et al.  Augmented behavioral characterization for modeling the nonlinear response of power amplifiers , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).