FINITE ELEMENT METHOD WITH EDGE ELEMENTS FOR ANISOTROPIC WAVEGUIDE PROBLEMS
Abstract
This paper presents the finite element analysis of eigenmodes in arbitrarily shaped anisotropicwaveguides by using high-order edge elements. The method uses the variational expression of thepropagation constant, which is expressed in terms of the transverse components. This variationalexpression is suited for analyzing dispersive waveguides, in which the medium varies with afrequency such as ferrite. The shape function uses an edge element which has the field componentsalong the edge as unknown parameters which satisfy the tangential continuity condition of thefields across material interfaces. In addition, the use of edge elements can reduce the number ofunknown parameters and the time of computation. Hence, the method can yield good accuracycompared with a method that uses a vector shape function. The result of comparison is shown in theexample of a dielectric-loaded waveguide. To verify the usefulness of this method, an example of acircular waveguide partially loaded with ferrite where the applied static magnetic field in thelongitudinal direction of propagation is demonstrated. The computational results show that thedispersion curves of this method satisfy those of other numerical methods in the past and have agood accuracy.
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