Non-Homogeneously Distributed Circularly Polarized Wide-Band Holographic Metasurface

In this article using non homogeneously distributed subwavelength isotropic metallic square patches on the grounded dielectric substrate, a holographic metasurface antenna (HMA) is designed which radiates circularly polarized (CP) beam at multiple frequencies ({f<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</inf>} = {15 GHz, 16 GHz, 17 GHz }). A progressive phase shift is incorporated in high gain, compact proposed HMA (13.3 λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> x 13.3 λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf>) to get the circular polarization at all the frequencies. Based on leaky wave excitation theory, this HMA is excited by monopole which is fed at the center of the surface. According to microwave holographic theory, non-homogeneous distribution pattern of metallic square patches causes the directive radiation pattern in the broadside direction ({θ, φ} = {0 °,0 °}) at required frequencies. The HMA gives average 18.2 dBi (g<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">avg</inf>) gain for all the frequencies with 3.26 GHz axial ratio bandwidth (ARBW). The proposed HMA structure, S11 (dB) plot and 2D, 3D gain plot with AR at each frequency are presented here.