A dielectric biconvex lens design for high-gain spiral antenna

This paper describes a design for a high-gain antenna that combines a dielectric lens and a spiral radiator. The gain of the proposed spiral antenna with a biconvex lens was remarkably increased compared with that of a conventional spiral antenna with an added conical cavity wall. The narrow beam width was reasonably achieved using the optimized biconvex lens. The author confirmed that the beam width and the average gain are greatly influenced not by the lens thickness but by the focal length.