Three-element homogeneous layer of cylindrical dielectric resonator antenna for wideband applications

In this paper, a new design is presented and discussed for achieving wide bandwidth using simple shaped dielectric resonators (DRs). The proposed antenna design consists of three homogeneous layers of stacked cylindrical dielectric resonator antenna (CDRA). The three DRs used here and named as lower DR, middle DR and upper are arranged on top of each other and displaced form each other in such a fashion that the center position of each DRA follows the position of a right angled triangle vertices. For excitation purpose a simple co-axial probe feed is used. The proposed antenna is designed in various steps with same permittivity of DR layers and different center positions. The principle behind achieving wideband response is to combine various modes excited within DRs. In this regard it has been shown, in this paper that without displacing the three layers modes are not merged and when DRs are displaced mode merging occurs resulting in wide bandwidth. The proposed antenna has achieved input reflection coefficient (below -10 dB) of 61.01% in the frequency range of 4.1-7.7 GHz with center frequency of 5.9 GHz. Simulations are performed using. In order to obtain optimal antenna geometrical parameters, parametric analysis have been performed using Ansys high frequency simulator structure (HFSS) software. The effects of parameters such as position of dielectric resonators, permittivity of layers and probe height have been investigated on antenna performance. The proposed antenna provides broadside radiation and provides maximum antenna gain of 7.24 dB and radiation efficiency of approximately 88% throughout the frequency band.