Design and Fabrication of High Dielectric GRIN Lens for a Directive Antenna Using a Hybrid Filled Voxel Additive Manufacturing Technique

ABSTRACT Additive manufacturing (AM) has been used to produce materials and structural components with graded or anisotropic mechanical properties, primarily through variations in local porosity. However, beyond structural applications, there are significant technological opportunities for additively manufactured devices with spatial gradations of functional properties, such as magnetic and dielectric properties, to provide novel device functionality. This paper describes a hybrid filled voxel AM technique for producing devices with 3D, spatially graded relative permittivity. The approach is illustrated through simulation‐informed design, fabrication, and microwave characterization of a filled voxel dielectric gradient refractive‐index (GRIN) lens that combines a 3D‐printed polymer lattice with a manual additive assembly of pre‐densified dielectric voxels of tailored permittivity. The hybrid‐AM GRIN lens enabled a significant reduction in the length of a transmitting microwave antenna horn by 50%, while also enhancing its directivity from 6.75 to 7.74 dB at 15 GHz. We demonstrate the potential of filled voxel hybrid‐AM graded devices to improve microwave device performance and to facilitate miniaturization.