Meta-surface based convex reflectors for generating highly directive pencil-beams and fan-beams

We propose to collimate the reflected electromagnetic fields from convex reflectors by using meta-surfaces. More specifically, both umbrella-shape and polygon prism convex reflectors are shown to be capable of generating highly directive pencil-beams and fan-beams, respectively, when integrated with meta-surfaces offering additional gradient phase distributions over the reflecting boundaries. Steerable beams from both reflectors are also verified from the full-wave simulations. Finally, we practically implement such meta-surface based convex reflectors loaded with properly devised subwavelength ring patches and demonstrate their functionalities of tuning reflected electromagnetic beams with greatly enhanced reflections. Our approach of generating well collimated electromagnetic fields from convex reflectors would be applicable to conformal components on the non-planar platform for the highly directive radiations.