Finite element analysis of complex modes in inhomogeneous waveguides

A finite-element analysis of complex modes in a shielded image guide is presented. The method of analysis, free from spurious solutions, is based on a novel variational expression using only two field components. Results are given for the behavior of complex modes in the presence of varying frequency, permittivity, and losses. It is shown how the presence of losses in the dielectric insert causes the separation of the complex modes, which cease to be conjugates of each other.<
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