基于功放记忆效应的动态X参数模型的研究

Research of dynamic X parameter model based on memory effects of power amplifier

为了更加准确地表征功放的记忆效应,提出了一种新的动态X参数功放模型。该模型是对动态X参数模型的一种改进,利用FF(feed-forward)模型技术提取出表征功放记忆效应的核函数,并将其用于代替X参数表达式中的非线性函数。X参数表达式中的静态部分仍采用PHD(poly harmonic distortion)模型的非线性函数,并将动态部分进行合理的简化。相比传统的动态X参数建模方案,所提模型不仅仿真精度高,而且仿真速度快。经仿真测试NPT1004功放的数据,利用所提出的新的动态X参数模型对功放建模,结果证明了本模型仿真功放的ACPR(adjacent channel power ratio)的误差减小了3 d B,从而验证了该模型的可行性,对今后利用动态X参数对功放的建模具有参考价值。

This paper presented a new dynamic X parameter amplifier model, in order to more accurately characterize the memory effects of the power amplifier. The model was an improvement on the dynamic X parameter model. It used FF model- ing techniques to extract the kernel function which was used to represent the memory effects of power amplifier, and replaced the nonlinear expressions in X parameter by the kernel function. The static part of X parameter expressions still used PHD model, and the dynamic part was simplified reasonably. Compared to traditional dynamic X parametric modeling program, the proposed model achieves not only high simulation accuracy, but also fast simulation speed. This paper used the new dynamic X parameter model presented to build model for power amplifier, and simulated and tested NPT1004 power amplifier data. The result shows that this model amplifier ACPR error is reduced 3 dB. It verifies the feasibility of the program, and the dynamic X parameter amplifier model has important reference value on modeling for power amplifier.