A Rectangular Dielectric Resonator Antenna (RDRA) array fed by a Dielectric Image Line (DIL) through a narrow slot is numerically investigated based on Finite Element Method (FEM). A single DRA, at first, is studied and its radiation characteristics are obtained at 10 GHz. To increase gain of single element RDRA, an array of three element RDRAs is introduced and its radiation properties are provided. Results show that for single RDRA, 7.7 dB gain is obtained, while backward radiation is 5 dB less than the radiation in broadside. Techniques to improve antenna array gain and reduce backward radiation including placing four sidewalls at the corner of the ground and putting a reflector at the backside of structure are applied. Numerical results show that antenna array without sidewalls provide gain of 10.2 which is 2.5 dB higher than the gain of single element RDRA. Furthermore, for the DRA array with sidewalls, maximum gain of 11.5 dB is achieved which is 1.3 dB higher than the gain of the DRA array without sidewalls. Radiation performance of the antennas including return loss, radiation patterns, and gain versus frequency plots are reported.

Keywords