Analysis of Dielectric Waveguide Problem by Boundary Element Method.

The boundary element method,introduced originally as a numerical technique for solution of potential problems and structural engineering problems, has been applied to numerous electromagnetic problems, most of which are in the area of boundary value problems. However, little has been reported on the applications to eigenvalue problems such as analysis of the propagation characteristics of a transmission line. In this paper, the boundary element method is applied for the eigenmode analysis of a dielectric waveguide to demonstrate the usefulness of the method for eigenvalue problems. From the numerical analysis nonphysical (spurious) solutions similar to the case of finite element method are found to appear. Since the appearance of such spurious solutions significantly damages the usefulness of the method, it is important to develop a procedure to eliminate them. Spurious solutions are studied to determine their cause, and an improved boundary element method is proposed that does not admit them. [ABSTRACT FROM AUTHOR]