Realization of Large Dielectric Resonator Antenna ESPAR

A large array of dielectric resonator antenna (DRA) is designed in X-band based on electrically steerable parasitic array radiator (ESPAR) concept. This large array consists of 240 perforated DRAs, which are uniformly excited by a parallel-series feeding network. By employing the perforation technique, the need for aligning and bonding individual DRA is eliminated. The subarrays are placed in an interleaved arrangement to suppress the grating lobes. To best explore the differences and advantages of our approach, the proposed ESPAR is compared with the beam steerable reflectarray antenna and traditional phased array antenna. The present large ESPAR can incredibly reduce the number of phase shifter by 80% in comparison with the conventional phased array, which makes it inexpensive. A prototype is fabricated, which achieves a maximum boresight realized a gain of 22.4 dBi. The agreement between measured and simulated results is very good.