Performance Improvement of Monopole Loaded Hybrid Dielectric Resonator Antenna by using Sleeve-like Structure

In present work, one novel approach has been implemented to improve the performance of monopole loaded hybrid dielectric resonator antennas (DRAs). The antenna has been designed by incorporating two different kinds of conical dielectric resonator rings with conventional monopole. Further, the performance of the antenna has been improved by introducing sleeve-like structure. The proposed antenna operates over the frequency range 4–30 GHz which provides 120% impedance bandwidth (
$\mathbf{S}_{11}\leq-10\ \mathbf{dB}$
) with peak gain of about 5 dBi. It can be used as an electromagnetic sensor suitable for ultra-wide band applications.