Wide-Band Wide-Angle Beamsteerable Meta-Lens Antenna for Terrestrial/Nonterrestrial 5G Communication Systems

Abstract

A highly efficient low-profile binary metasurface lens (BMSL) antenna is designed and developed to achieve wide-angle beamsteering at the millimeter-wave band of fifth-generation (5G) aerospace communication systems. First, a subwavelength-sized phase-shift element (meta-element) with a crossed-arrow geometry having two-line symmetry structure is designed possessing special characteristics of insensitivity to polarization as well as the oblique angle of incidence, wide-band transmission, and compactness. Further, 1-bit quantized radial phase-graded metasurface lens is designed by arranging the proposed elements in $19\times19$ array resulting in an aperture area of $33.6~\lambda _{0}^{2}$ . To realize beamsteering along 0°, ±15°, ±30°, ±45°, and ±60°, BMSLs with distinct phase-quantization are designed and spatially fed through antipodal Vivaldi antenna (AVA) which acts as a primary feed source positioned at optimum focal point thereby radiating highly concentrated beams in the intended directions. The complete BMSL antenna system is then fabricated and characterized in an ideal free-space environment achieving a measured peak gain of up to 20.8 dBi in broadside direction and 1.6 dB of maximum scan loss for ±60° steering. The proposed BMSL antenna achieves an aperture efficiency of 28.4 % at 28 GHz and a −3-dB gain bandwidth of 16.5 %. Thus, the proposed BMSL antenna is a promising contender for facilitating terrestrial (air) as well as nonterrestrial (space) communication links between low-Earth orbit satellites and 5G base stations.