Low-cost method for waveguide device components fabrication at 220 – 325 GHz

This work explores a rapid design and manufacturing approach to realize complex 3D pillar type filter and transmission line structures for applications in the 220 – 325 GHz range and which cannot be economically reproduced by conventional machining processes or present rapid prototyping methods. The significance of this investigation is that at sub-millimetre-wave or THz frequencies, where the waveguide features are less than 100µm and the skin depths are less than 200nm, the exact conductor shape and surface roughness have a significant electrical effect and any variations result in an important disagreement between the modelled and measured characteristics. This is a proof of concept validation of the rapid manufacturing approach and is aimed at paving the way to a range of THz passive waveguide components, where the availability and cost of such components is typically prohibitive and where the surface roughness is minimized and highly reproducible. Using this approach the fabrication times can be as rapid as a few days and can yield many hundreds of highly reproducible millimetre scale components.