Dielectric Flat Lens for Millimeter-Wave Applications

This paper proposes a dielectric flat lens for gain enhancement. The proposed lens consists of a set of concentric rings with different refractive index values for each. The proposed lens is based on the graded steps of the effective refractive index of the semi-spherical lens. The radius of the designed lens is 6λ, and the thickness is optimized based on a tradeoff between the gain and the side lope levels. A horn antenna is used to examine the performance of the designed lens at 28 GHz frequency in terms of the maximum gain, and side lobe level.