A broadband metasurface Luneburg lens for microwave surface waves

A broadband planar microwave Luneburg lens made of a three-layer metasurface with hexagonal symmetry is presented. This metasurface supports a transverse-electric mode confined to the surface that presents very low dispersion and a stable mode index across a broad frequency band. This enables the lens to operate in the range of frequencies between 8 GHz and 19 GHz. The lens was manufactured using a lithographic technique with three 25 μm copper-coated Mylar sheets. The resulting device is only 75 μm thick, flexible, and light-weight.