Estimation of Intermodulation Rejection Value as a Function of Frequency in Power Amplifier Using AM-AM and AM-PM Diagrams Based on Power Series Analysis
- 1 Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
- 2 Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
- 3 Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
Abstract
A method to predict intermodulation (IM) products of two tone test based on Amplitude to amplitude (AM-AM) and amplitude to phase (AM-PM) diagrams of power amplifier is proposed in this paper. An RF power amplifier is mathe-matically modeled by a power series in order of 13. Coefficients of the transfer function are obtained by odd-order polynomial fitting of the transfer function of the power amplifier that is modeled by power series, with AM-AM and AM-PM diagrams. Because of considering AM-PM distortion, coefficients have become complex. By using this transfer function, analytical expressions of IM products are derived. Frequency effect of IM products are modeled in suggested method to estimate the effects of changing in input frequency on output. With the mean of this factor the model is able to predict IM products of wideband frequency input. Simulated results agree well with the predicted method in comparisons.
- R. Raich, H. Qian and G. T. Zhou, “Orthogonal Polynomials for Power Amplifier Modeling and Predistorter Design,” IEEE Transactions on Vehicular Technology, Vol. 53, No. 5, 2004, pp. 1468-1479. doi:10.1109/TVT.2004.832415
- B. Larkin, “Multiple-Signal Intermodulation and Stability Consideration in the Use of Linear Repeaters,” Proceeding of 41st IEEE Vehicular Technology, St. Louis, 19-22 May 1991, pp. 747-752.
- Q. Wu, M. Testa and R. Larkin, “Linear RF Power Amplifier Design for CDMA Signal,” IEEE MIT-S Digest, Corvallis, June 1996, pp. 851-854.
- G. T. Zhou and J. S. Kenney, “Predicting Spectral Regrowth of Nonlinear Power Amplifiers,” IEEE Transactions on Communications, Vol. 50, No. 5, 2002, pp. 718-722. doi:10.1109/TCOMM.2002.1006553
- C. H. Tseng, “Estimation of Cubic Nonlinear Bandpass Channels in Orthogonal Frequency-Division Multiplexing Systems,” IEEE Transaction on Communications, Vol. 58, No. 5, 2010, pp. 1415-1425. doi:10.1109/TCOMM.2010.05.080573
- M. E. Gadringer, C. Schuberth and G. Magerl “Behavioral Modeling of the Frequency Translation Process in Direct Conversion Transmitters,” International Journal of RF and Microwave Computer-Aided Engineering, Vol. 20, No. 3, 2010, pp. 347-359. doi:10.1002/mmce.20439
- S. J. Yi, S. Nam, S. H. Oh and J. H. Han, “Prediction of a CDMA Output Spectrum Based on Intermodulation Products of Two-Tone Test,” IEEE Transaction on Microwave Theory and Techniques, Vol. 49, No. 5, 2001, pp. 767-946. doi:10.1109/22.920152
- A. H. Coskun and S. Demir, “A Mathematical Characterization and Analysis of a Feedforward Circuit for CDMA Applications,” IEEE Transaction on Microwave Theory and Techniques, Vol. 51, No. 3, 2003, pp. 767777. doi:10.1109/TMTT.2003.808582
- C. Liu, H. Xiao, Q. Wu and F. Lit, “Linear RF Power Amplifier Design for Wireless Signals: A Spectrum Analysis Approach,” International Conference on Acoustics, Speech, and Signal Processing, Vol. 4, 2003, pp. 568-571.
- A. M. A. Hemmatyar and F. Farzaneh, “Predicting of InterModulation Rejection Values for the First and Second Adjacent Channels in Feed-Forward Linearised Microwave Amplifiers Using Closed-Form Expressions,” IET Microwaves Antennas & Propagation, Vol. 1, No. 3, 2007, pp. 782-789. doi:10.1049/iet-map:20060342
- M. L. Ku, S. H. Lu, L. C. Wang and S. H. Yan, “Nonlinear Effect of Receiver Amplifier for 60 GHz Radio Communication,” IEEE International Conference on Vehicular Technology, 5-8 September 2011, pp. 1-5. doi:10.1109/VETECF.2011.6093112