同轴线-矩形波导结散射特性的数值分析

Scattering at junction between a small coaxial line and a large rectangular waveguide

提出了一种数值分析同轴线-矩形波导结散射特性的模式匹配方法。采用同轴线和矩形波导的本征模函数表示电磁场分量,通过同轴线-矩形波导结截面横向场分量匹配获得波导结的散射参数,引入电场模式匹配矩阵的解析形式提高了计算效率。给出了基于模式匹配法数值仿真的各种同轴线-矩形波导结散射特性及仿真结果分析,并与3维全电磁波分析软件HFSS的仿真结果进行了比较,二者非常吻合。模式匹配法计算效率高,能广泛应用于微波毫米波元器件及系统结构的设计与优化。

This paper presents a formally exact solution （mode-matching method） to the problem of scattering at the junction between a small coaxial line and a large rectangular waveguide. The eigen-mode functions for both coaxial line and rectangular waveguide are used to express the field components in both regions and the transverse field components are then matched to obtain the scattering parameters of the waveguide junction. The E-field mode-matching matrix is analytically derived in closed-form for efficient computation. Numerical results for a few waveguide problems involving the coaxial line-to-rectangular waveguide junction are presented and discussed. The mode-matching method results are in excellent agreement with those obtained by Ansoft＇s HFSS and the method has high computation efficiency, which can be used to optimize the structure of the microwave components.