互易手征小球偏心加载导体球谐振腔研究

On Resonant Frequency Shifts of a Conducting Sphere Resonantor Eccentrically Loaded with a Small Reciprocal Chiral Sphere

基于形状微扰和边界条件 ,采用数值仿真 ,率先定量研究了互易手征小球偏心加载导体球谐振腔谐振频偏随小球相对位置和媒质参数特别是手征导纳的变化规律 ,从而揭示了手征导纳这一重要参数的一种可行测量方案。该方法明确指出了通过测量频偏进而测量手征导纳的一种非常重要的思路。

Shape perturbation is an efficient method for studying loaded cavity. We extend this method for the first time to a small reciprocal chiral sphere which is eccentrically loaded in a conducting sphere cavity, as shown in Fig.1. For magnetic modes (TE mns ), we use complex spherical vector wave function [3] to describe the external electromagnetic field of the chiral sphere (eqs.7 and 8). For the inner field of the chiral sphere, we adopt the generalized complex spherical vector wave function [7] (eqs.9 and 10). The unknown coefficients in eqs.9 and 10 are determined by the boundary conditions of the chiral sphere surface (eqs.13 and 14). After a lengthy derivation, we get the resonant frequency shift (eq.25). For electric mode (TM mns ), based on reciprocal theorem, the resonant frequency shift is given by eq.26. Figs.4 and 5 give the numerical results of the variation of resonant frequency shift with permittivity (ε) , and chiral admittance (ξ) respectively. They show that in TM 122 and TM 132 , the resonant frequency shifts vary greatly with ε and ξ . To our best knowledge, we did not find anything like Figs.4 and 5 in the open literature.