A Microstrip-Coupled Rectangular Dielectric Resonator Antenna (RDRA) operated at the dominant TEy111 mode of operation is investigated numerically and experimentally. The effect of resonator displacement along the feed line on the radiation performance of the RDRA is studied. The antenna structure is simulated using the High Frequency Structure Simulator (HFSS software package. A few experimental set-ups were also examined and the antenna parameters were measured. The simulated results are presented and compared with those obtained by experiments