Effect of Parasitic Elements on Spherical Probe-Fed Antennas

Theory and experiment of a spherical probe-fed conformal antenna with a parasitic element mounted on a spherical multilayer structure are presented in this paper.Linear Rao-Wilton-Glisson (RWG) triangular basis functions are applied in MPIE formulation. Current distributions oncoaxial probe and conformal radiating elements are computedby using spatial domain Dyadic Green's Function (DGF) and its asymptotic approximation. A prototype of such an antenna isfabricated and tested. The effect of the parasitic element on the input impedance and radiation patterns of the antenna isinvestigated. It is shown that the antenna characteristics are improved significantly with the presence of the conductingparasitic element. Good agreement is achieved between theresults obtained from the proposed methods and the measurement results

کلیدواژه ها:

Asymptotic approximation ، dyadic Green’s function ، spherical probe-fed antennas