Double parabolic cylinder pencil-beam antenna

Radiation from a point source placed on the focal line of a parabolic cylinder is reflected in succession from this cylinder and from a second parabolic cylinder crossed so that its focal line coincides with the directrix of the first cylinder. The two reflections result in a parallel beam. The theory is applicable to both microwaves and light. The advantages of shipping the cylinders in the form of flat sheets and the possibilities of independent control of horizontal and vertical beamwidths and shapes are pointed out. Experimental models have been built and tested.