Characteristics of Space, Leaky, and Creeping Waves in a Uniaxial Dielectric Rod

The excitation of space wave, leaky wave, and creeping wave in a cylindrical rod with uniaxial anisotropic permittivity and permeability is thoroughly characterized. The closed-form expressions of the space, leaky, and creeping waves in the uniaxial rod are derived for all source polarizations through the rigorous formulation, taking into account all higher order azimuthal harmonics and TE-TM mode coupling for the space and creeping waves. Conditions for obtaining a high space- and leaky-wave directivity are thoroughly examined for all source polarizations with variation in the vertical and horizontal permittivities/permeabilities and the rod radius. The leaky-wave phase and attenuation constants with variation in the rod parameters are investigated to identify the leaky-wave propagation regions of the uniaxial rod. Beam-scanning characteristics for the space and leaky waves are examined with variation in the uniaxial rod parameters. The complex pole loci for the azimuthally propagating creeping waves around the uniaxial rod are also investigated to identify the leaky, the creeping, and the trapped-mode regions.