Development and Characterization of a Plastic 3D-Printed only external-layer Metal-Coated Waveguide Antenna Array

In this work, the design, fabrication, and experimental verification of a plastic 3D printed metal-coated double-ridged waveguide antenna array is presented. The antenna array consists of four dielectric-loaded square input to circular aperture double-ridged horns arranged in a diamond pattern. A feeding network of one input port to four output ports made on dielectric-loaded double-ridged waveguides is also designed. A novel design methodology to simplify the metalcoating of complex monolithic antenna array structures made on plastic is introduced. A proof-of-concept was fabricated using SLA 3D plastic printing technology and metal-coated only on the external layer using galvanization with Copper and Nickel. The behavior of the antenna array is experimentally verified in the anechoic chamber where a maximum directivity of 17.5 dBi in the frequency bandwidth from 8 to 21 GHz is obtained.