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. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1124-1129, 2014
1.Chinese Acad Sci, Inst Opt & Elect, Chengdu 610209, Peoples R China 2.Chinese Acad Sci, Chongqing Inst Green & Intelligent Technol, Chongqing 401122, Peoples R China
Yuan, Guishan,Dong, Xiaochun,Deng, Qiling,et al. A BROADBAND SLAB LENS ANTENNA FORMED FROM GRADIENT REFRACTIVE INDEX METAMATERIALS COMPOSED OF CROSS- SHAPED CELLS[J]. MICROWAVE AND OPTICAL TECHNOLOGY LETTERS,2014,56(5):1124-1129.