Dispersion Relation of Corrugated Circular Waveguides

Abstract

Electromagnetic propagation in corrugated waveguide has been of considerable interest because it supports balanced HE₁₁ mode. The HE₁₁ mode has excellent characteristics for the feed of parabola antenna. In this paper, we obtain dispersion relation of all possible propagation modes by Fourier transform method which is applicable to other general periodic structures. Unlike other methods based on anisotropic surface impedance, the fields are expressed through a series of modal eigenfunctions in the corrugation. The residue calculus is utilized to relate the modal magnetic currents in rapidly-converging series and to show the equivalence of the method to Floquet theorem.