An omnidirectional filtering dielectric resonator antenna based on metal patches

A novel filtering dielectric resonator (DR) antenna (DRA) is designed in this article. By using a single-layer planar feed structure, the TM01 delta and TM011+delta modes of a cylindrical DR are excited. The proposed filtering DRA achieves a good omnidirectional radiation performance and a flat gain response. By loading a crossed patch with four shorting pins on the feed structure, the lower edge of the passband obtains a steep roll-off rate. By plating four metal patches on the side wall of the DR, a radiation null (RN) is successfully introduced at the upper sideband of the DRA. The suppression levels of the proposed filtering DRA in the lower and upper stopbands are above 18 dB. Therefore, the proposed filtering DRA achieves filtering function without additional circuits. For demonstration, a prototype DRA is fabricated and measured. The simulated and measured results are basically consistent.