Wideband Compact Circularly Polarized Patch Antenna Array Using Non-uniform Metasurface

A circularly polarized wideband non-uniform metasurface integrated $2 \times 2$ antenna array is designed for C-band applications. The wideband performance is achieved through the use of non-uniform metasurface. A sequentially rotated phase network is utilized for uniform power distribution in the $2 \times 2$ array antenna. Stubs are employed in patch design to enhance impedance bandwidth. The parameters of the antenna array are $1.24 \lambda_{0} \times \mathbf{1. 2 4} \lambda_{0} \times \mathbf{0. 0 7 3} \lambda_{0}\left(\mathbf{6 8} \times \mathbf{6 8} \times 4 {~mm}^{3}\right)$ at a center frequency of 5.5 GHz. Dual orthogonal feeds are used to generate circular polarization in the proposed antenna. As a result, the achieved bandwidth covers from 4.68 to 7.17 GHz in the C -band, with an axial ratio remains less than 3 dB over the range of 3.11 to 6.55 $\mathbf{G H z}$ and a peak gain of 13.03 dBic. Simulations indicate that the array exhibits right-hand circularly polarized radiation in the broadside direction, characterized by a symmetrical profile, minimal side lobe levels, and an 80% radiation efficiency.