Comparative study of gain enhancement of a Dielectric Resonator antenna using three superstrates for millimeter-wave applications

In this paper, a comparative study of three high gain hybrid antennas with different superstrates is presented. The three superstrates are a dielectric slab, a frequency selective surface (FSS) with square ring elements and a dielectric slab, and a FSS with strip dipole. A hybrid Dielectric Resonator antenna (DRA) is the excitation source. This antenna gives a good impedance bandwidth over the entire ISM band (57 GHz- 64 GHz). CST Microwave Studio software package is used to investigate the antennas. The input impedance, the gain, and the far field patterns have been presented. It is observed that the electromagnetic characteristics of a dielectric resonator antenna (DRA) can be enhanced by using different superstrates. The gain can be improved to near 16 dBi. And a gain of 11 dB over the entire ISM band have been achieved.