In this paper, a low profile circularly polarized
single layer metasurface based antenna is designed and validated through simulation. The antenna consists of non-uniform
metasurface on the front side of the substrate and a co-planar
waveguide(CPW) fed slot antenna on the back side. The slot is
oriented at 450 with respect to xy plane. The metasurface consists
of two different sized unit cells to obtain two resonant modes.
The each unit cell is rectangular shaped where its dimensions
are adjusted to achieve orthogonal phase shift required to obtain
circular polarization. The larger dimension center patches are
responsible for lower resonant frequency and smaller patches
surrounded which are place in the corner are responsible for
obtaining higher resonance frequency. The two resonances are
combine to achieve wider axial ratio bandwidth(ARBW). The
simulated impedance bandwidth of 55.01% and an ARBW of
12.58% is obtained. The peak gain of 8.04 dBi is achieved at
5.75GHz with 0.5dBi variation over the entire bandwidth. The
radiation pattern is oriented in broadside direction with better
cross-polarization value of minimum -20dB in both XZ and YZ
plane. The results demonstrates that this design is well suitable
for modern 5G communication which demands the consistent
gain, good polarization purity and wide bandwidth.
 

Circularly polarized antenna;metasurface;axial-ratio bandwidth;Low profile;Unit cell