Metallized 3D Printed THz Hollow Waveguide Components

This paper presents the realization and validation of metallized 3D-printed WR-1.0 (750–1100 GHz) hollow rectangular waveguide components. The components are fabricated as 15 mm long H-plane split-block using Projection Micro Stereolithography (P$\mu$SL) 3D printing, achieving high precision, with tolerances within $\pm$15 $\mu m$ and a surface roughness down to 200 nm. Following printing, the pieces were metallized via Physical Vapor Deposition (PVD) of a silver alloy. Two components, a straight hollow waveguide and a single-resonant cavity filter, were validated. The straight thru demonstrated low-loss, reaching an average dissipative attenuation ($\alpha'_D$) of $0.078\,\text{dB}/\lambda_g$. This attenuation is over eight times lower to prior monolithic metallized 3D-printed waveguide components at this band. As the first metallized 3D-printed split-blocks realized at WR-1.0, this work validates a scalable manufacturing approach for prototyping and low-volume production of high-precise and low-loss waveguide components for THz applications.