In this article, the value of anisotropy ratio $\kappa / \mu $ for ideal symmetric three-port circulator is derived by using the transmission line equivalent model. This value plays a vital role in the design of circulator. In order to obtain the value of $\kappa / \mu $ , eigenvectors of the scattering matrix S for the circulator are given first. Then, one-port transmission line equivalent models for ideal circulator are presented. Finally, the value of $\kappa / \mu $ is derived in terms of the relationships between reflection coefficients of three one-port transmission line equivalent models. Furthermore, a three-port waveguide circulator is designed in order to verify the theoretical value of $\kappa / \mu $ . And the experimental value of $\kappa / \mu $ is approximately equal to the theoretical result. Also, this value derived in this article is in good agreement with the one obtained by field method and circuit method in published literatures.

中文翻译：

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各向异性比的测定 κ/μ 使用传输线等效模型的对称三端口环行器

在本文中，各向异性比值 $\kappa / \mu $ 使用传输线等效模型推导出理想对称三端口环行器。该值在循环器的设计中起着至关重要的作用。为了获得价值 $\kappa / \mu $ ，首先给出循环器的散射矩阵 S 的特征向量。然后，给出了理想环行器的单端口传输线等效模型。最后，价值 $\kappa / \mu $ 是根据三个单端口传输线等效模型的反射系数之间的关系推导出来的。此外，为了验证理论值，设计了一个三端口波导环行器 $\kappa / \mu $ . 和实验值 $\kappa / \mu $ 近似等于理论结果。此外，本文推导出的这个值与已发表文献中通过场法和电路法得到的值非常吻合。