Design of CPW-fed Star-Shaped Monopole Antenna for UWB Applications using Transmission Line Model

Abstract

This article presents a structure of coplanar waveguide (CPW)-fed star-shaped monopole antenna (SSMA) with a pair of quarter-circular-slit (QCS) and partly-hexagonal-ring-slit (PHRS) defected ground structure. By inserting a pair of QCS and PHRS on the rectangular ground plane, an excellent impedance bandwidth is achieved i.e., 139 % (from 2.2--12.21 GHz). The dimension of the SSMA is about 0.286λ l ×0.216λ l mm 2 , where λ l is the wavelength in free space at the lowest operating frequency i.e, 2.2 GHz. The transmission line model (TLM) of the SSMA is presented and it shows the antenna behavior based on the effect of each element. It is observed that the characteristics of the TLM model are close to the simulation result using the CST simulator. From the results, it is observed that the proposed ultra-wideband (UWB) antenna close to omnidirectional radiation patterns and suitable for UWB Applications.