Broadband CPW-fed circularly polarized antenna with equiangular tapered-shaped feedline for ultra-wideband applications

Abstract

A novel coplanar waveguide (CPW)-fed circularly polarized (CP) antenna is proposed. The antenna is composed of a square ground plane with a circular slot and an equiangular tapered-shaped feedline. With the use of a special shaped feedline, the axial ratio (AR) bandwidth of the proposed antenna is about 61.9% (2.9-5.5 GHz), which is larger than most of similar antennas proposed before. In addition, the impedance bandwidth, determined by 10-dB return loss, is between 2.9-20 GHz, which makes the antenna be used for ultrawideband (UWB) applications.