Conformal strip excitation of dielectric resonator antenna

In this paper, a new excitation scheme that employs a conducting conformal strip is proposed for dielectric resonator antenna (DRA) excitation. The new excitation scheme is successfully demonstrated by using a hemispherical DRA whose exact Green function is found using the mode-matching method. The moment method is used to solve the unknown strip current from which the input impedance is obtained. Novel recurrence formulas were obtained so that the impedance integrals are evaluated analytically. This solves the singularity problem of the Green function and substantially reduces the computation time. An experiment was carried out to verify the theory. The co- and cross-polarized field patterns are also shown in this paper. In addition, an experimental technique which deals with the problem of an air gap between the DRA and the ground plane is presented.