Bandwidth enhancement of a CPW-fed monopole antenna with small fractal elements

In this paper, a technique of adding small fractal elements to the polygon shape radiator of a CPW-fed monopole antenna for bandwidth enhancement is proposed and experimentally studied. Based on the multi-resonance effect of the fractal elements, three closely spaced resonant frequencies are produced over the antenna bandwidth which leads to coverage of the standard UWB bandwidth (3.1–10.6 GHz). Effects of increasing the number of the polygon sides on S11 and radiation patterns are also investigated. Finally, three prototypes of the proposed antenna are fabricated and measured in order to verify the simulation results.