CPW-fed octagonal super-wideband fractal antenna with defected ground structure

Abstract

A coplanar waveguide (CPW)-fed octagonal super-wideband fractal antenna is presented. It comprises four iterations of an octagonal slot-loaded octagonal radiating patch, CPW feedline, and modified ground plane loaded with a pair of rectangular notches. An impedance bandwidth of 3.8-68 GHz (179%) - i.e. a17.89:1 ratio bandwidth - is achieved. Desirable radiation performance characteristics, including relatively stable and omnidirectional radiation patterns, are obtained over this range. The experimental and simulation results are found to be in good agreement. The designed antenna has the advantages of wider bandwidth and miniaturised size over the previously reported structures. © The Institution of Engineering and Technology.