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

The excitation of space-wave, leaky-wave and creeping-waves in a cylindrical rod with uniaxial anisotropic permittivity and permeability is thoroughly characterized. 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-wave and creeping-waves. Conditions for obtaining a high space-wave and leaky-wave directivity are thoroughly examined for all source polarizations with variation in the vertical and horizontal permittivity / permeability 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 is also investigated to identify the leaky, creeping and the trapped-mode regions.