Design and Fabrication of a Cost-Effective 3D-Printed Cylindrical Luneburg Lens

A cylindrical Luneburg lens with a gradient-index (GRIN) profile focuses electromagnetic waves by gradually reducing the refractive index (RI) from center to edge. However, conventional designs face challenges such as complex fabrication, material limitations, narrow bandwidth, and high costs. This study introduces a 3D-printed Luneburg lens with saw-tooth structures that achieve a smooth RI gradient through unit cells with cuboidal and cylindrical air voids, precisely tuning permittivity. With a diameter of 95.9 mm, a height of 30 mm, and operation in the X-band, the lens achieves a simulated gain of 14.07 dBi. In contrast, measured gains for cuboidal and cylindrical designs are 11.91 dBi and 12.85 dBi, respectively. This method offers a low-cost, high-performance alternative for GRIN lenses.