同轴任意槽形周期圆波导慢波结构色散特性的研究

The dispersion characteristics of the coaxialarbitrary-shaped-groove periodic slow-wave structure

用阶梯近似的方法分析任意槽形加载的圆波导慢波系统,利用各阶梯相邻面的导纳匹配条件以及中心互作用区与加载区的场匹配条件,获得了任意槽形加载周期慢波结构的统一色散方程.利用该色散方程,得到色散特性与CSTMWS仿真软件模拟结果良好符合.分别求解几种特殊槽形加载慢波结构的色散特性及耦合阻抗,其中,三角形结构色散和耦合阻抗均最弱,而倒梯形结构色散最强,耦合阻抗最大.

The dispersion equation of a coaxial arbitrary-shaped-groove slow-wave structure is derived by means of an approximate field-theory analysis, in which the continuous profile of the groove is approximately replaced by a series of rectangular steps, and the field continuity at the interface of two neighboring steps and the matching conditions at the interface between the groove region and central region are employed. The simulation results by CST MWS are in good agreement with the numerical calculation results of the dispersion equation. We have calculated the dispersion characteristics and the coupling impedance of the slow-wave structures with some special groove shape. It shows that the dispersion characteristic of the triangle-groove structure is the weakest and the coupling impedance of it is the least, while the dispersion characteristic of the inverted-trapezoid-groove structure is the strongest and the coupling impedance of it is the largest.