基于负载牵引和记忆效应的X参数的功放建模

Power amplifier modeling of X-parameter based on load-pulling and memory effect

为了更加快速准确地描述带有记忆效应的射频功率放大器,基于传统的X参数模型,结合负载牵引和功放的记忆效应,提出一种新型X参数功放建模方法。新方案首先引入负载反射系数;然后利用双记忆路径模型提取出表征记忆效应的非线性函数替换核函数,采用幅度、负载反射系数与频率三变量作为输出信号的新型前馈(FF)结构建立X参数模型;最后采用阶跃信号代替原始的双音信号提取模型用以达到简化模型提取方法的目的,进而提高模型提取的可行性。经仿真测试CGH40045F功放的数据,利用提出的新型X参数建模方案对功放进行建模,仿真功放的相对误差与传统X参数模型、FF结构X参数模型、FB结构X参数模型相比,均有所减小;与FF结构模型和反馈(FB)结构模型相比,仿真时间分别减少了4. 08 s和1. 64 s。实验结果表明,该模型能够更加快速有效地拟合带有非线性记忆效应的射频功率放大器。

In order to describe the Radio Frequency(RF)power amplifier with memory effect more quickly and accurately,a new X-parameter power amplifier modeling method was proposed based on the traditional X-parameter model combined with the memory effect and load-pulling of the power amplifier.Firstly,the load reflection coefficient was introduced into the new scheme.Secondly,the two-memory path model was used to extract the nonlinear function to represent the memory effect instead of the kernel function.Three variables including amplitude,load reflection coefficient and frequency were regarded as output signals to build the new Feed-Forward(FF)structure.In the end,the step signal was used instead of the original two-tone signal to simplify the model extraction method and improve the feasibility of model extraction.By using the proposed new X-parameter modeling program to model power amplifier,the simulation results of the power amplifier CGH40045F data showed that compared with the traditional X-parameter model,FF structure X-parameter model and FeedBack(FB)structure X-parameters model,the relative error was reduced;compared with the FF model and the FB model,the simulation time was reduced by 4.08 s and 1.64 s,respectively.The results prove that the model modeled by the proposed mehtod can characterize the amplifier with non-linear memory effect more quickly and effectively.