Wideband circularly polarized antenna using metasurface

Abstract

A wideband circularly polarized (CP) antenna with a compact size of 0.64λ0×0.64λ0×0.27λ0 operating at the frequency of 2 GHz is presented. The antenna consists of a 4-way power divider, a patch antenna and a metasurface (MS). The input signal is fed to the 4-way power divider and the signals at the outputs of the 4-way power divider are coupled to a patch antenna using 4 orthogonally oriented L-shape probes. The MS is designed to work with the antenna. The CP antenna is studied and designed using computer simulation. Results show that, the MS can improve the axial ratio bandwidth (ARBW), boresight co-polarization gain and cross-polarization of the patch antenna. The CP antenna, with the use of the MS, has a very wide impedance bandwidth (IMBW) of 1.06–3.21 GHz (100.7%) and ARBW of 1.2–3.11 GHz (88.6%), which are larger than those of all other designs found in literature, yet having the smallest size.