Lenses Designed by Transformation Electromagnetics and Fabricated by 3D Dielectric Printing

Quasi-conformal transformation optics (QCTO) is applied to design electromagnetic lenses for focusing and collimating applications at microwave frequencies. Two devices are studied and conceived by solving the Laplace's equation that describes the deformation of a medium in a space transformation. The first lens is applied to produce an overall directive in-phase emission from an array of sources conformed on a cylindrical structure. The second lens allows deflecting a directive beam to an off-normal direction. Prototypes presenting a graded refractive index are fabricated through three-dimensional (3D) polyjet printing using solely dielectric materials. Performed experimental measurements validate the proposed lenses.