Reconfigurable Directive Multiple Beam Emissions Lens Formed with 2D and 3D Linear Coordinate Transformation Optics

A linear coordinate transformation lens that can transform the omnidirectional radiation into reconfigurable number of highly directive beams is presented. In 2-D space, by using our method, the parameters of transformed medium are homogeneous and positive, and the number of beams has no effect on parameters. Compared with those previous designs, the proposed structure is much more realizable. Extending this method to 3-D case, the resulting parameters become even simpler and isotropic, which leads to broadband characteristics of the designed device and the lens can be manufactured by common metamaterials and isotropic materials. Full wave simulations are performed to validate our design. The proposed linear coordinate transformation method could promote development towards practicability in this field.