Design Of Ultra-Wideband Circularly Polarized Cpw-Fed Antenna With A Metasurafce Substrate

This paper describes the novel design of coplanar waveguide (CPW)-fed quadrilateral-shaped compact planar antenna for ultra-wideband (UWB) application. The fractional axial ratio (ARBW) bandwidth of the antenna for circular polarization (CP) is 56.64% (5.91-10.58GHz) and its fractional impedance matching bandwidth (IMBW) is 137.1% (3.1-17.5GHz). The proposed antenna structure is simple and compact; hence its design is efficient. The gain of the antenna varies between 3.33 to 8.9dBi. The gain further improves by placing a metasurface below the antenna up to 4.8dBi, without affecting its axial ratio bandwidth, while its IMBW reduces to 118.2% (4.5-17.5GHz). Simulated and measured results are shown to be in good agreement.