Additive Manufacturing of Graded Dielectric Superstrate for Phased Arrays

Additive manufacturing technologies have enabled a wide range of custom devices and advanced material fabrication. It is reported here an approach developed to provide dielectric graded RF metamaterials through an active mixing nozzle developed in prior work and novel low loss inks. By utilizing a active mixing nozzle, we can provide a continuous gradient across the z-stack of a material from a permittivity of 3 to 1.06 with the inclusion of a top layer of Rohacell. Utilizing this superstrate material surpasses traditional approaches in manufacturing graded index materials which require gluing substrates with various dielectric constants together or machining varying holes across a substrate or space filling 3D printed parts. In this study we developed a non-destructive characterization approach through micro-CT. By utilizing our approach to fabricate a superstrate we can improve the scan angle and bandwidth of traditional phased arrays