Three-Stacked Dielectric Ring Resonator Loaded Hybrid Monopole Antenna for Improved Ultrawide Bandwidth

In this paper, a new wideband and compact three-segment composite dielectric ring resonator (DRR) antenna excited by an axi-symmetric coaxial monopole has been introduced. The proposed antenna has been investigated numerically and experimentally for enhanced impedance bandwidth. At the lowest operating frequency, the presented antenna has a footprint area of just 0.16 lambda(0) x 0.16 lambda(0) According to the measurement results, the antenna offers a fractional impedance bandwidth equal to 159% with 8dBi peak gain. The antenna provides symmetrical and stable monopole like radiation pattern over the entire impedance bandwidth. With such performance, the suggested antenna can be usefully employed in different wideband applications such as electromagnetic interference (EMI) and defense applications.