Quadrilateral-Shaped Wideband Circularly Polarized CPW-Fed Monopole Antenna

Abstract

This paper presents a new type coplanar waveguide (CPW)-fed quadrilateral-shaped compact planar monopole antenna with wideband circular polarization (CP). The antenna operates in the C-band (5.96-8.0GHz), as well as in the X-band (8.0-11.72GHz) and provides circular polarization (CP) in both bands. The fractional axial ratio (AR) bandwidth for CP 55.86% (5.96-10.58GHz) and fractional bandwidth of 118.2% (4.5-17.5GHz) for the return loss (S11) is realized simply by designing a quadrilateral-shape monopole with an asymmetric ground plane. The proposed CPW monopole antenna structure is simple and compact, its design is efficient, and it has a wide impedance matching (S11) band as well as 3-dB axial ratio (AR) operating band. Simulated and experimental results are presented to validate the antenna design and are shown to be in good agreement.