Abstract: Memory polynomials have been widely used to model PA behavior because of their easy identification. This paper proposes a new rational function power amplifier model for TD-LTE communication system on account of research of the conventional memory polynomial. The presented model based on the ratio of two general memory polynomials which not only characterizes the small-signal behavior of PA, but also predicts large-signal behavior accurately, and makes use of LS techniques to extract the model parameters. Model test is conducted by the strong nonlinear input and output data exported from the DPA circuit which is designed by NXP PA models in ADS circumstance. The results indicate the presented new model achieves better performance than conventional memory polynomial model, it has higher precision to model PA characteristics, the rational function model has important reference value on development and research of the RF PA behavioral modeling.

Key words: Time Division-Long Term Evolution（TD-LTE）, power amplifier, memory polynomial, behavioral model, rational function

摘要： 鉴于参数辨识过程简单的优点，记忆多项式模型已被广泛用于模拟功率放大器的行为。在记忆多项式功放模型的基础上，提出了一种面向TD-LTE通信系统的有理函数功放新模型。该模型通过基于两个记忆多项式模型的比率，在保证模拟小信号输入功放特性的同时还能够对大信号驱动下的功放行为进行准确预测，应用最小二乘法技术提取模型参数。利用NXP功放管设计Doherty功放电路，在ADS环境下导出强非线性输入输出信号数据实现模型性能验证。结果表明，提出的新模型性能优于传统的记忆多项式模型，具有更高精度，能够精确模拟功率放大器特性，对射频功放行为建模的研究与发展具有重要参考价值。

关键词: 分时长期演进（TD-LTE）, 功率放大器, 记忆多项式, 行为模型, 有理函数