基于三端口网络模型的折叠波导行波管注波互作用理论研究∗

摘要

A general equivalent model for slow-wave structure is established in this paper, if the unit cell of the periodic slow-wave structures is represented by a three-port network and the parameters of the equivalent model are determined by a high frequency structural simulator. In this method, there is no need to find a complicated equivalent circuit, and the fields in the tunnels can be calculated by the high frequency software directly. Therefore, the three-port network model is simpler than the analytic method and no more complex than the common equivalent circuit model. A one-dimensional nonlinear beam-wave interaction theory suitable for the folded-waveguide traveling wave tubes (TWTs) is accomplished based on the three-port network model. And a one-dimensional nonlinear beam-wave interaction code, which complies with the MATLAB language, is used to simulate a folded-waveguide TWT. The difference between the results obtained from the code and the experimental data is less than 10%. This theory can be used in the design of novel folded-waveguide TWTs and research on nonlinear simulations.%将周期性慢波结构中的单元结构等效为一个三端口网络，利用高频结构模拟软件确定等效模型的参数，由此建立了一种通用的慢波结构等效模型。该方法不需要进行复杂的电路等效，直接由高频软件得到通道内场分布，因此较解析方法简单，又不像等效线路模型那么烦琐。基于该三端口网络模型，建立了适用于折叠波导行波管的一维注波互作用非线性理论模型，编写了数值计算程序，对一支折叠波导行波管进行了模拟。该理论模型模拟的结果与实验结果误差小于10%。该理论模型可以用于指导新型折叠波导行波管的设计及非线性模拟研究。