Modal analysis of anisotropic cylindrical waveguides

In this article, modes are analytically expanded for cylindrical waveguide with anisotropic walls. With certain conditions, hybrid modes may appear with fundamental mode cutoff frequency lower than the TE₁₁ fundamental mode of the equivalent metallic waveguide and/or with a larger single-mode frequency band. In some cases, the E transversal field shape of the fundamental mode can be more linear than the equivalent TE₁₁ mode. Such properties of guided waves may result in the reduction of waveguide cross section or higher radiation efficiency in antenna applications.