中文摘要：

对一种全金属慢波系统一正弦波导的高频特性进行了理论分析．在用一系列相连矩形阶梯逼近余弦槽的基础上，对慢波结构进行了合理的区域划分，获得了各区域的场表达式．考虑槽区的高次驻波项，采用场匹配和导纳匹配相结合的方法，导出色散方程和耦合阻抗表达式．以应用于220GHz行波管的正弦波导为例进行高频特性的数值求解，理论计算值与全三维电磁软件CST—MWS的仿真值符合良好．在此基础上、详细分析了尺寸参数变化对正弦波导高频特性的影响．

英文摘要：

A theoretical analysis of the high frequency characteristics for an all-metal slow-wave system （SWS）, i.e., a sine waveguide, is performed in this paper. The continuous profile of the cosine groove is approximated by a series of connected rectangular steps, and the SWS is divided into several regions reasonably, then the expressions of the field in all the regions are given. The dispersion equation and coupling impedance formula of the SWS are obtained by using the field matching theory combined with the matching of the admittance. The high frequency characteristics for a sine waveguide used in a 220 GHz TWT are discussed, and the calculation results are in good agreement with those obtained from three-dimensional electromagnetic simulation software CST-MWS. The effects of the geometrical parameters on high frequency characteristic of the sine waveguide are also investigated in detail.