耦合腔慢波结构冷测特性的计算方法

对几种用3维MAFIA仿真软件以及利用其准周期边界条件和后处理模块计算耦合腔行波管慢波结构的色散和耦合阻抗等冷测特性的方法进行了讨论，另外还对两种阻抗＿总阻抗和Pierce耦合阻抗的定义进行了充分讨论。考虑到休斯结构耦合腔行波管的电子是与耦合腔慢波结构的负一次谐波发生作用和耦合阻抗应该是电子注截面上的平均值等，指出总阻抗和Pierce耦合阻抗之间相差一个因子，考虑了这个修正因子之后，其结果将更接近实际情况。用这些方法计算耦合腔行波管的冷测特性，得到了与实验冷测值十分接近的结果。

Method of simulation on coupled cavity slow wave structure cold-test characteristic

In this paper, the three-dimensional simulation code MAFIA and its quasi-periodic boundary conditions and the postprocessor are used to determine the coupled cavity slow wave structure cold-test characteristics. Some simulation methods of dispersion and on-axis interaction impedance of Hughes coupled cavity slow wave structure have been studied. Two different defintions of the whole impedance and the Pierce impedance are discussed. The electrons interact with the negative once resonance of microwave and the interaction impedance is the mean value on the beam. There is a factor difference between the whole interaction impedance and the Pierce interaction impedance. The simulation result is consistent with the actual measurement result.