Frequency-Dependent Directive Radiation of Monopole-Dielectric Resonator Antenna Using a Conformal Frequency Selective Surface

Development of a conformal frequency selective surface (FSS) for radiation diversity of hybrid monopoledielectric resonator antenna has been demonstrated in this paper. In the proposed method, a planar FSS screen with meandered unit cell is designed to be reflective at 5 GHz followed by its mapping on a cylindrical surface of flexible dielectric material. The proposed conformal reflector when kept at a specific distance from the radiating element improves the bandwidth of the antenna from 26.8% to 53.67% in 4-6 GHz band. A significant enhancement of 5-6 dBi in gain is also achieved over this band. Gain of the antenna with reflector is maintained around 9.5 dBi with a variation of similar to 1.5 dB. On the other hand, omni-directional radiation of the antenna is maintained at an upper band of 7-9 GHz. Simulations have been performed using ANSYS High Frequency Structure Simulator (HFSS). Experimental measurements of the fabricated prototype have been provided. The proposed design is useful to achieve pattern diversity in multiband antenna system.