A broadband slab lens antenna formed from gradient refractive index metamaterials composed of cross‐shaped cells. Issue 5 (May 2014) - Yuan, Guishan
Abstract A slab lens antenna has been designed to enhance the directivity of a horn antenna efficiently in a wide range of frequencies. A gradient refractive index metamaterial is utilized to compensate phases of electromagnetic waves radiated from a horn, which can transform the cylindrical wave into a plane wave. To obtain broadband property, the gradient refractive index metamaterial composed of cross‐shaped conductor, which works in a nonresonant status is designed, and the metamaterial is proved to be broadband, polarization insensitive, and lossless. The slab lens is designed by a collection of metamaterial unit cells with different geometric parameters, where the effective refractive index of the unit cells are determined by the size of cross‐shaped conductors to form the required inhomogeneous refractive index distribution. The simulation and experiment results show that the lens located in front of a horn can considerably compress the antenna's radiation patterns over a wide band range from 12 to 18 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1124–1129, 2014