中文摘要：

本文研究了由金属光子带隙结构以及金属膜片构建的Ka波段慢波结构的色散特性、工作模式的电场及耦合阻抗。结果表明，采用PBG缺陷结构的平均半径作为封闭边界代替PBG慢波结构的开放边界，从而由色散方程快速得到色散特性，数值计算的结果与模拟及实验结果基本一致；进一步研究表明，工作模式的电场以及耦合阻抗主要分布在慢波结构表面附近。

英文摘要：

Various physical values, including the dispersion characterisitics, field distributions and the impedance of operation mode,of the Ka band slow-wave structure with a metal photonic band-gap and a metal plate as the periodic unit were theoretically analyzed. In the calculation, the open boundary of the photonic band gap （PBG） was replaced by a novel closed boundary model with an appropriate radius equal to the average radius of the defects;and a dispersion equation was derived to calculate the dispersion characteristics. The numerically calculated results based on the dispersion equation were found to agree fairly well with both the simulated and the experimental results. Interesting finding is that the electric field and the coupled impedance of the operation mode focus near the surface of the slow wave structure.