High-efficiency Reflectarray Using Dielectric Resonator Elements

In this paper, a dielectric resonator-based unit-cell is used to design a reflectarray antenna with improved efficiency. The unit-cell is a dielectric structure composed of a cylindrical element placed on a squared base having a ground plane at the bottom. The diameter of the cylinder is the parameter chosen for controlling the phase of the reflection coefficient. To verify its effectiveness, the proposed cell is employed to design a Ka-band offset reflectarray consisting in 52 × 52 elements. Simulated results show that the antenna is able to achieve a maximum gain of 32.3 dBi at 30 GHz, corresponding to an aperture efficiency of 55%.