Designing refracting surfaces to generate a line-shaped directivity diagram

A method of designing a refracting surface to generate a directivity diagram represented as a vector function of one argument is presented. A general relationship for the refracting surface is derived as an envelope of a parametric family of rotational ellipsoids or hyperboloids (depend on of the refractive indexes of the mediums, divided by the refracting surface). Each ellipsoid or hyperboloid in the family transforms a spherical illuminating beam from the point source into a beam with plane wavefront of desired direction. The incident and refracted rays lie on the circular cone. We design a refracting surfaces to generate a line-segment directivity diagram.