Directive radiation from a diffuse Luneburg lens.

Transformation electromagnetics has opened possibilities for designing antenna structures. Using an analytical approach, we demonstrate here how directive antenna radiation can be achieved from an omnidirectional source behind a diffuse surface. This diffuse surface has been obtained by an optical transformation of a Luneburg lens. Two different transformation approaches have been proposed (polynomial and sinusoidal), and for both cases, the resulting material properties have been simplified to ease the fabrication by using all-dielectric media. Therefore, the proposed design has no upper boundary to the operational frequency. Directive radiation has been achieved from thin diffuse structures, which demonstrates promising future possibilities for this technique.