Compact Circularly Polarized Printed Slot Antenna with a Wrench Shaped Patch for UWB Application

Abstract

A broadband circularly polarized square slot antenna (CPSSA) is presented using a coplanar waveguide (CPW) feed-line. The antenna
occupies a volume of 25 ×25 × 0.8 mm3 and is approximately six fold smaller than the state-of-art antennas of a similar type. The antenna
comprises of a square loop shaped ground-plane with three L-shaped ground strips located at its internal corners, and a wrench shaped patch
with a semi-circular tuning stub that is connected to the feed-line. The proposed antenna is shown to provide an impedance bandwidth covering
2.92–11.42 GHz (118.5%) with VSWR ≤ 2. Its axial-ratio bandwidth (ARBW) is wider than 50% over the frequency range 5.05-8.42 GHz. The
simulated and measured results show the feasibility of the antenna for practical applications.