Full-Wave Green's Function Analysis of a Coaxial Probe Coupled Two-Layer Hemispherical DRA with an Imperfect Concentric Conductor

In this work, full wave analysis of a coaxial probe coupled two-layer hemispherical dielectric resonator antenna (DRA) with an imperfect concentric conductor is investigated. Green's function method is used to analyze the proposed structure. Impedance boundary condition is applied on the interface of imperfect surface and dielectric region to derive the unknown constants. Electromagnetic boundary conditions are also applied on the dielectric-dielectric and dielectric-air interfaces to obtain the relevant unknown constants. The Method of Moment with sinusoidal basis and testing function is used to obtain the current distribution on the probe surface and thereafter the input impedance, reflection coefficient and radiation pattern are evaluated. The effect of imperfect surface, dielectric permittivity, sphere radius and probe length on the input impedance and reflection coefficient is also reported.