Modeling of wideband radio frequency power amplifiers using Zernike polynomials

Abstract

In this article, we suggest a new set of basis functions that are based on Zernike polynomials for the behavioral modeling of radio frequency power amplifiers (PAs). The modeling of highly nonlinear PAs exhibits numerical instability that degrades the accuracy of the model parameters and predistorter modeling efficiency. Simulation results show that the proposed polynomial model is more suitable to resolve the numerical instability problem and proves to have greater accuracy with reduced complexity. A Doherty PA driven by a multicarrier wideband code division multiple access signal was used for validation; and, the obtained results show that the new model exhibits superior numerical stability as the nonlinearity order and memory depth of the model increase. V C 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 00:000-000, 2012.

An accurate physical knowledge-based model for behavioral modeling and digital predistortion of power amplifiers

“…In the DPD performance assessment experiment, in order to validate the DPD performance of SPK model for different PAs, a GaN DPA (V ds ¼ 28 V, V gs ¼ À2.3 V) operated at 2.65 GHz was added to the test and it was driven by the single carrier 16QAM signal. Figure 4 shows the test bench setup [3,8]. This experimental setup was composed of a computer, a vector signal generator (VSG), a PA and a vector signal analyzer (VSA).…”

“…Numerous behavioral models have been proposed, but most of them are highly sensitive to the adopted signals and PAs because of the lack of physical analysis [2][3][4][5][6][7][8]. It is of no surprise that distinct signals or PAs may lead to different model accuracy and DPD performance.…”

Behavioral modeling for concurrent dual-band power amplifiers using 2D hammerstein/wiener models

“…Among all the research topics, behavioral modeling is a vital task for the PA. It should be noticed that accurate analysis of the PA's nonlinear behavior provides effective prediction of its nonlinearity, and the behavioral modeling is also an essential step for the implementation of digital predistortion (DPD) linearization of PA []. Furthermore, as modern communication schemes employ higher order modulation signals with wide bandwidth (e.g., 5–20 MHz) and nonconstant envelopes, memory effects become another critical problem in the behavioral modeling of PA.…”

“…A memory polynomial (MP) model was proposed for DPD purpose for PA. Then, the MP model was further applied in the work . The work by Jebali et al proposed a Zernike polynomials model for the behavioral modeling of wideband PA. The dynamic deviation reduction‐based Volterra (DDR‐Volterra) model was proposed in and applied to DPD linearization in .…”

“…Power amplifier (PA) is one of the most important components of the radio frequency (RF) front end in modern wireless communication systems. However, the PA is an inherently nonlinear device and the nonlinearity caused by it is a commonly known problem subjected to intensive research in the past decades [1][2][3][4][5][6][7][8][9][10][11][12][13]. Among all the research topics, behavioral modeling is a vital task for the PA.…”