X-band performance of three-dimensional, selectively laser sintered waveguides

In this paper, the feasibility of using selective laser sintering to create high-frequency metallic structures is investigated. Two WR90 waveguides are fabricated directly from a CAD drawing using an automated laser sintering tool from e-Manufacturing Solutions (EOS). The waveguide performance is measured from 8 GHz to 12 GHz and compared to a standard commercially available brass waveguide and the differences in loss performance will be used to extract an effective conductivity of the laser fabricated parts, both prior to and after polishing the critical surfaces. Polishing the inside of the waveguides demonstrates the available performance of the casting alloy used and the impact of the natural surface roughness on the performance of parts fabricated using the EOS powder-based laser sintering process. Overall, a performance comparable to the brass waveguide is achieved.