Anastigmatic Three-Dimensional Bootlace Lens

摘要

This invention relates to a three-dimensional bootlace lens with minimum possible focusing aberrations, minimum possible focusing size and minimum possible dielectric loading. The feed and lens surfaces are in the shape of a spherical cap and covered by contiguous arrays of radiators. The region between the inner surfaces of the lens is filled with a nonuniform dielectric material with an index of refraction which constantly changes from the center line outwardly. Lens ports are connected to a radiating antenna array by means of coaxial transmission lines all of which have the same length. The axial feed point has a focusing performance which is perfect. For all other points the lens is free of all first-order aberrations including coma. The outputs of the lens can be used to feed a planar radiating antenna array so as to produce a multiple directive beam in one angular dimension or to feed a circular array so as to make it amenable to scanning or multibeam feed systems that are used with linear arrays.