Dielectric guide cassegrain antennas with ring focus parabolic reflector

This paper shows a design method of a dielectric guide cassegrain antenna with a ring focus parabolic reflector. Geometrical optics is applied to shape a subreflector on a top of the dielectric guide. Validity of the design method is clarified by numerical analyses. The electrical fields around the dielectric guide show the ring focus is achieved successfully. As a result, uniform phase distributions are obtained at the aperture of the main reflector.