A FILTERING DIELECTRIC RESONATOR ANTENNA WITH HIGH BAND-EDGE SELECTIVITY

A filtering rectangle dielectric resonator antenna (DRA) with high band-edge selectivity is proposed in this paper. The DRA is fed by a simple hybrid feeding structure consisting of a microstripcoupled slot on the bottom and a thin metallic strip on the side of DRA to excite the fundamental TEy1δ1 mode. The feeding structure establishes a cross-coupled mechanism which includes electric and magnetic coupling. This mechanism introduces two radiation nulls at the band edge without any filtering circuits. By using the designed hybrid feeding structure, a bandpass filtering response is obtained. For enhancing band-edge selectivity, a shorted stub is introduced to weaken the coupling between the two microstrip stubs of the feeding structure. A wide impedance bandwidth of 19% and a flat gain around 5.6 dBi are realized. To validate the proposed design, a prototype is fabricated and measured, showing a favorable agreement with the simulated results.