Dielectric lens antennas have grown in popularity for use in millimeter and sub-millimeter applications. They provide good efficiency, especially in the case of the elliptical dielectric lens, which has high focusing properties. By properly relating the eccentricity of the lens to the dielectric constant, and feeding the lens at one of its focal points, the majority of the rays are refracted in the "forward" direction, thereby constructing a plane phase front.
In the case of the elliptical lens, the high aperture efficiency (~105%) ensures an antenna with a reduced diameter when compared to a standard equal-gain conical horn antenna.
The antenna may be designed for a center frequency, lens relative permittivity and a gain between 15 and 30 dBi....Typical radiation pattern at the center frequency of the operating band Reflection coefficient of the antenna