终端辐射开路圆波导的反射

Reflection of Terminal Radiation Open Circular Waveguide

终端开路的圆波导反射特性的估计,对于喇叭天线的设计非常重要,也可以用于复数介质材料介电常数的测量。圆波导终端开路,存在着电磁波向半无限大空间的辐射,采用模式扩展的方法对圆波导反射进行估计,引入一个大的圆波导,替代半无限大辐射空间,辐射问题转化成波导结的问题,通过模式扩展的方法进行求解,使用了复化和外推法技术从而避免了收敛慢的缺陷,改善了分析的准确性,对于不同几何形状、电气参数的情况的反射系数进行了讨论,并给出了数值结果。

The evaluation of the reflection characteristic of open-ended circular waveguide is important for the design of horn antenna and useful for the dielectric constant measurement of complex dielectric material. The electromagnetic wave radiation to the half-infinity space exists in the terminal open circular waveguide. This paper uses the mode-expansion method to evaluate the reflection from the terminal open circular waveguide, and introduces a big circular waveguide to substitute the half-infinity radiation space. The radiation problem is transformed into the waveguide junction problem,which can be solved by the mode-expansion method. The complexification and extrapolation technique are employed to avoid the drawback of slow convergence and the accuracy of the analysis is improved, the reflection coefficient of various geometrical and electric parameters are discussed and the numerical results are presented in this paper.