Numerical and experimental studies of a helical antenna loaded by a dielectric resonator

Abstract

A helical antenna loaded by a dielectric resonator (DR) is rigorously studied. Effects due to the dielectric core are analyzed by replacing it with an equivalent polarization current density so that only the homogeneous dyadic Green's function is required. Special interest is paid to the handling of the singularity of the dyadic Green's function in the source region. Two coupled integral equations are obtained by enforcing the boundary condition on the surface of the helical antenna and by equating the total electric field inside the dielectric resonator. The method of moments is used to solve the coupled equations and hence to obtain other properties of the antenna, such as the input impedance, the radiation pattern, the beam width characteristics, and the axial ratio. Experimental measurements were conducted and compared with the theoretical results. It is found that excellent agreement is observed between theoretical values and experimental measurements. Various characteristics of the dielectric resonator loaded antenna are also discussed.