Colloquium announcement

Faculty of Engineering Technology

Department Design, Production and Management
Master programme Mechanical Engineering

As part of his / her master assignment

Wijlens, T.C.J. (Tim)

will hold a speech entitled:

Novel technique of producing waveguides using additive manufacturing



Existing radar systems based on PCB antenna arrays are running into limitations with overheating. A problem that cannot be overcome by simply increasing the size of the cooling system. Looking into the past at older design ideas, namely waveguides that at the time were phased out in favor of the cheaper PCB panels due to cost, might be the way forward. Manufacturing technology has not slowed down. Using the modern Additive Manufacturing (AM) techniques Stereo Lithography Apparatus (SLA) with materials Rigid10K and Accura Bluestone and Selective Laser Melting (SLM) with AlSi10Mg as the material, a number of these waveguides were fabricated. A copper metallization step was performed on the SLA printed waveguides as this was a neccesary step to produce functioning waveguides. The goal was to gain insight into the factors that have an impact on the attenuation, signal loss per meter[dB/m], of an AM produced waveguide and see if one can be produced to be within 10% of a commercial part or better.

RF attenuation measurements on a Vector Network Analyzer (VNA) were used to determine how much loss the different waveguide samples had and how they compare to each other. It became clear that, as with every new innovation, there are start-up problems with this new method of producing waveguides. In this instance the metallization step of non-conductive samples turned out to be a challenge in that the copper layer was not uniform and had significant burn-like marks on it that certainly caused the waveguide to have a high signal loss on the affected samples. Nevertheless additive manufactured waveguides look promising if these problems can be overcome as is demonstrated by the metal printed sample that had quite good performance fresh off the printer.