Bandwidth adaptive behavioral model with dynamic structures for radio frequency power amplifiers

Abstract

To cope with the degradation of digital predistortion when bandwidth changes, a bandwidth adaptive behavioral model with dynamic structures for radio frequency (RF) power amplifiers (PAs) is proposed in this article. By applying the nonlinear post-compensation technology, PA's nonlinearity is decomposed and analyzed. Short-time Fourier transform and transfer functions are adopted to study the influence of bandwidth variation on the linear memory effect. Based on PA's memory effect analysis, a bandwidth adaptive model with dynamic structures and a coefficient update scheme with low complexity are proposed. Experiments carried on PAs show that the proposed model achieves similar linearization performance as other conventional models. Simultaneously, the proposed model has fewer coefficients and a reduction in the coefficient update of at least 50%.

A modified broadband weighted magnitude‐selective behavioral model for digital predistortion of radio frequency power amplifiers

“…2 However, in the case of broadband and multiband, the PA exhibit significant nonlinearity, which causes the behavior model of PA far more complex. 3,4 Not only the complexity of the model will increase, but also there will be nonconvergence in the process of parameter extraction when the model with a large number of coefficients. 5 Therefore, the model complexity problem can be solved in two ways without sacrificing performance.…”