Resonant Frequencies Studies in Isotropic and Anisotropic Spheroidal Cavities by an Extended Integral Equation and a Local Point Technique: Invited Paper

In this work the resonant frequencies in spheroidal metallic cavities loaded with isotropic and anisotropic material, are studied. For the case of isotropic infills, an extended bound-ary condition integral equation method (referred hereafter as extended integral equation) is employed while, a local point tech-nique is developed for anisotropic loadings. The anisotropy used in this work is of uniaxial type while prolate and oblate spheroidal cavities are studied. The extended integral equation is based on numerical integration of the involved special functions along the generating curve of the spheroidal surface. On the contrary, the local point technique satisfies the requisite boundary condition at a predefined set of points on the generating curve without the necessity to apply integration techniques. The emerging hybrid modes are examined and discussed. In particular, the spheroidal cavity spectrum for isotropic infills is extracted and compared by both the extended integral equation and the local point technique. Concerning uniaxial loaded cavities, the resonant frequencies are calculated solely by the local point technique. To validate these results, we utilize the HFSS commercial software. The local point technique turns out to be computationally efficient in terms of CPU time and memory consumption, as compared to the commercial solver. Various numerical results are presented and discussed.