A Closed-form Design Method for GRIN Lens Design

Abstract

A design method for graded-index lens antennas is proposed. The method consists of proposing a phase function in a region of space that meets the boundary conditions of the design and rescaling the optical path. The latter allows us to adjust the lens’s refractive index. The designed lens has a length of 6λ, an aperture width of 8.7λ. The highest required refractive index is 1.6. A directivity value of 25.4 dB, and a -24 dB side-lobe level are attained. The design functionality is verified using COMSOL.