Full Wave Analysis of the Wideband Multilayer Hemispherical DRA Using the Method of Generalized Reflection and Transmission Coefficients

Green's function has been formulated using the method of generalized reflection and transmission coefficients for an arbitrary directed electric point source, which is placed in multilayered spherical media. To verify the formulation three-layer hemispherical DRA excited by coaxial probe has been taken and computed results are verified with HFSS simulation. To resolve the current on the surface of the probe, moment method with piecewise sinusoidal basis and testing functions are used, from which the input impedance, reflection coefficient, and radiation pattern have been obtained. Maximum impedance bandwidth of 63.22% and 48.75% for the center and offset coaxial probe excitation have been achieved respectively.