Experimental realization of a broadband conformal mapping lens for directional emission

We experimentally realize a transformation lens for directional emission at microwave frequencies. The refractive index of the lens, based on the design of conformal mapping, has variation from 1 to 4 inside a semi-circular geometry. By drilling subwavelength holes in dielectric plates inhomogeneously, we design the lens sample. The scanning measurements of the electric field of the lens demonstrate the high directivity of emission, within a broadband working frequency region of 7-11 GHz. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4731877]