High gain multi-band circularly polarized bi-layered metasurface patch array antenna with dual-orthogonal feeds

Abstract

In this article, a renovated patch array antenna is developed that achieves features such as high gain and circular polarization by introducing a bi-layered eight-shaped metasurface on top of the feed. The antenna is designed as a dual-feed array structure, utilizing silicon materials for the substrates and featuring two gold patches operating at frequencies of different dimensions with two orthogonal feeds optimized to achieve wide bandwidth operation. Along with modifying the gaps and arcs in the antenna, circular polarization can be made possible with an appropriate pattern of the unit cell. Finally, a designed eight-shaped metasurface has been used to control wave propagation, improve polarization switching properties, and increase the bandwidth of impedance and also axial ratio. The substrates of the renovated patch antennas and that of the bi-layered metasurface are respectively made of silicon and silicon dioxide to reduce undesired waves. Different Components are separated from each other with silicon material without an air gap. The impedance bandwidth covers a wide range of frequencies from 3.24 to 5.44 THz, about 50%. The results show that the axial ratio is in four ranges (3.48–3.74 THz), (4.08–4.16 THz), (4.23–4.27 THz) and (5.05-6 THz), which are in good coverage with the impedance bandwidth.