Lens effect in parallel plate waveguide realized by using a metamaterial surface

This paper presents an idea for designing a planar Lüneburg lens inside a parallel plate waveguide by using an artificial metamaterial surface. In the present article, the surface is realized by a bed of nails. By modulating the heights of the nails, a variable impedance is obtained on one boundary of the parallel plate thus obtaining an equivalent desired refraction index for the guided wave. The method can be used for designing other kinds of planar lenses.