Analysis of Rotationally Symmetric Resonators by the Finite Element Method.

This paper proposes an analysis method based on the finite-element method that can be applied to such rotationally symmetric structures as circular cylindrical resonators. In general, the main drawback associated with the finite-element methods for electromagnetic eigenvalue problems is the mixing of the nonphysical or spurious solutions with the physical solutions. However, in the method proposed in this paper, all the spurious solutions have zero eigenvalues and can easily be separated from the physical solutions, thereby eliminating the problem of spurious solutions. Moreover, the computation can be treated as two-dimensional, thus a large saving in computer time and storage is obtained compared to three-dimensional computations. Theoretical equations are derived and by using a numerical example the rightness of this method is demonstrated. [ABSTRACT FROM AUTHOR]