3D-Printed Millimetre-Wave Waveguide Passive Devices and Antennas

3D printing (or additive manufacturing) has become an increasingly common manufacturing tool for microwave filters. The technology has made the jump from laboratories to real world applications and been used in real space missions. This relatively new manufacture technique has also started finding applications at even higher frequencies into millimeter-wave (mm-Wave) and sub-terahertz (sub-THz) regime [1], as 'high-precision' 3D printers become available. Without a consensus, but for the sake of clarity, here 'high-precision' printers are referred to those with a manufacture tolerance of under 10 \\m over a sufficiently large printing volume of centimeter scales, to be generally usable for microwave and mm-wave waveguide devices.