Evolution and Optimization of a Low-Cost Coaxial-Waveguide-Transition

This paper investigates the effect of a metallic coating using highly conductive silver paint on previously manufactured low-cost copper and aluminium WR90 coaxial waveguide transition (CWT) prototypes, based on the same manufacturing processes. The results will be compared to each other. The deembedding of the prototype with varying numbers of applied layers of silver-conductive lacquer reveals the significant impact of increasing conductivity on transmission parameters for low-cost designs. The final product in the form of the silver prototype, with a partially over 95% transmitted performance, is indeed competitive compared to the industrially manufactured WR90 CWT considered here. In conclusion, a further improvement of the transmission parameters can only be achieved through an optimization of the surface structure like roughness.