针对微波驱动源、固态调制器等对宽平顶脉冲源的应用需求，开展了基于脉冲形成网络输出准方波的理论研究与分析设计。首先采用Prony算法获得准方波波形的解析表达式，然后基于最佳一致逼近的优化控制思路，列出极点控制方程，采用数值方法求解非线性方程组，获得优化波形参数。在此基础上采用阻抗函数匹配的算法求解出脉冲形成网络的元件参数初始值，根据工程设计的实际情况舍弃部分参数并对个别参数进行优化后，获得最终的元器件参数。通过理论分析与数值模拟相结合的方法，系统地给出了获取长脉宽、低纹波准方波脉冲形成网络的设计方法以及设计准则。该方法可用于设计任意阶低纹波系数的准方波脉冲源，也可用于设计其他输出波形要求的脉冲源。

For the application requirements of the high voltage pulse generator based on the pulse forming network(PFN) in the microwave driver and the solid-state modulator, the theory of the PFN with the trapezoidal pulse output was developed. First, the analytical expression of the trapezoidal pulse was obtained by the Prony algorithm. Secondly, the waveform parameters were optimized by using the best uniform approximation algorithm based on the equations of the optimal control with the maximum and minimum of the output wave, and solving these nonlinear equations with the Newton iteration method or other numerical methods. Then, the initial parameters of the PFN were worked out with the method of impedance matching. The final components parameters were obtained by rejecting some secondary parameters and adjusting a few of the main parameters. The method and criteria of the design for a PFN with the low ripple trapezoidal pulse output were proposed by theoretical analysis and numerical simulation. The results show that the proposed method can be used to design the PFN with any order and low ripple, and it can be used to design not only the pulse source with trapezoidal pulse output, but also the pulse sources with other pulse output.