Cutoff Frequencies of a Dielectric-Loaded Rectangular Waveguide With Arbitrary Anisotropic Surface Impedance

摘要

The coupled transcendental equations describing cutoff frequencies of TE and TM modes are deduced for a rectangular waveguide with arbitrary wall impedance. In the case of TE modes, their generalization is made to a rectangular guiding structure, which possesses both distributed wall impedance and inhomogeneous dielectric loading. Effective impedance is obtained for imperfectly conducting surface incorporating periodic rectangular corrugations along the direction of mode propagation. Circular waveguide bounded by such corrugated surface and rectangular impedance waveguide are considered as numerical examples. For these waveguides, the computations performed to determine the cutoff frequencies of TE guiding modes are validated against the results of the perturbation theory and the finite-element method.