Z-Shaped Dielectric Resonator Antenna for Ultrawideband Applications

A new dielectric resonator antenna (DRA) is introduced for ultrawideband applications. Three methods of a Z-shaped dielectric resonator, a bevel feeding patch, and an air gap between the DR and the ground plane are used to obtain an ultrawideband impedance bandwidth. The effective dielectric constant and the -factor can be reduced by introducing the air gap. The bevel-shaped feeding mechanism provides a smooth impedance transition from one resonant mode to another. Furthermore, the results show that by applying a Z-shaped DRA, the electric field inside the dielectric is reformed over the desired bandwidth leading to improve the matching. A comprehensive parametric study is carried out using CST to optimize the bandwidth of the proposed antenna. The measurement results demonstrate that the proposed DRA provides an ultra bandwidth of about 120%, ranging from 2.5 GHz to 10.3 GHz for the reflection coefficient less than .