Designing of High Gain Hemispherical Dielectric Resonator Antenna with Electromagnetic Band-Gap Structure

Abstract

The application of electromagnetic band-gap structure in gain enhancement of hemispherical dielectric resonator antenna has been investigated in this paper. It has been demonstrated that by efficiently suppressing the propagating surface waves, the performance of the dielectric resonator antenna can be significantly improved. The performance enhancement is due to the transformation of surface waves into the radiated ones by the cylindrical electromagnetic band-gap structure.The EBG substrate is based on themushroom-like structure, which is constructed as a combinationof two periodic structures.The first one is composed of three metalrings and the second of vertical grounding (metal)vias, which are placed so that they form radial and circular periodic structures. The metal rings are short circuited to the ground through these periodic vias. The periods of these two structures have been optimized using HFSS software. Dielectric resonator antenna is excited by a coaxial probe and integrated within a cylindrical EBG substrate to increase the antenna gain. The cylindrical electromagnetic band-gap structure consists of two distinctive periodic structures. The first structure as made of metallic rings, whereas the second structure is made of grounded vias, which ate placed radially and circularly. It is observed that the gain of the hemispherical DRA is enhanced by approximately 3.7 dB by using the cylindrical EBG structure.It is found that due to incorporation of the EBG structure, the bandwidth is enhanced by approximately two fold.The designed antenna provides a minimum gain of 6 dBi in the frequency range 3.3 GHz – 5GHz.The high frequency structure simulator (HFSS) software is used for the simulation of antenna structure.
Keywords— Dielectric Reosnator Antenna (DRA); Electro-magnetic Band Gap (EBG); High Frequency Structure Simulator (HFSS); Hemispherical DRA; Ground Plane