Shaping Focused Wave Beams in the Near Field by Spatially Distributed Caustic Synthesis

In this contribution, we introduce a technique for general focused beam synthesis based on ray-caustic shaping at microwaves and millimeter waves. Indeed, it is well-know from geometrical optics that caustics, i.e., the envelope of tangents to reflected rays, are characterizes by strong field intensity, and can be profitably used to focus beams on specific spatial trajectories. In this sense, the proposed approach represents a physics-based technique to shape the focusing capabilities of an antenna, beyond more conventional nondiffractive beams.