Vector Finite-Element Analysis of the Waveguide Modes Without Sprious Solutions Using an Improved Variational Expression

An improved vector variational expression for the finiteelement analysis of the dielectric waveguide problems is formulated in terms of the transverse magnetic-field components and the axial electric-field component. The axial electric-field component is eliminated by using the numerical matrix technique after constructing the matrix eigenvalue problem with the three field components. In this approach the squared values of propagation constants are obtained for the given frequency and no sprious， non-physical solutions exist in the whole region of a propagation diagram. To verify the accuracy of the present method， numerical results for the 2-dimensional waveguide are presented and compared with the exact solutions