Printed W-Band Luneburg Lens for Beamforming Applications

摘要

A novel low-cost printed circuit board Luneburg lens realization in W-band is proposed. This lens is fabricated by using a low-cost printed circuit board process. Concentric circles of holes in a substrate, covered on both sides with a metal sheet, realize a graded refractive index material. The effective refractive index contrast, necessary to implement the lens, is achieved by embedding a high dielectric constant substrate in the lens center using the same fabrication process. The periodic structure is analyzed by eigenmode analysis of a unit cell to calculate the effective refractive index. Field distribution of the proposed lens at 77GHz, excited by open-ended substrate integrated waveguides at its circumference, validates the conversion of the incident cylindrical wave to equiphase planar wave using the proposed lens.