Circular polarized transparent antenna for 5.8 GHz WLAN applications

Abstract

A novel design for a transparent circularly polarized circular slot antenna fed by a coplanar waveguide (CPW) is presented in this paper. The circular polarization is achieved by introducing a tapered split gap in the ring patch of the circular slot antenna in combination with unequal CPW ground arms. The antenna is designed using AgHT-4 laminated on a 2mm thick glass with a relative permittivity of 7. The proposed antenna is designed to operate at 5.8 GHz for WLAN applications. The tapered split gap and inequality in the lengths of the CPW ground arms contribute to a 3 dB axial ratio bandwidth from 5.4 to 6.2GHz. The proposed antenna has been studied theoretically and fabricated. The measured results show that the proposed antenna has a gain of 0.92 dB at 5.8 GHz. Reflection coefficient (S11), axial ratio (AR), and radiation patterns are presented and briefly discussed.