Micro-machining of test cavity for sub-terahertz antenna system via micro-EDM and micro-milling processes

This paper aims to analyse and compare the performance of two promising micro manufacturing processes, micro milling and micro EDM, when micro features for su b terahertz antenna are fabricated A functional cavity of a passive component of an antenna system that works at G Band is designed The component's design aims to enhance its sensitivity to manufacturing accuracy and surface roughness After the prelimin ary test, test cavities are fabricated and measured. Results show that both processes are able to match the design requirements (geometrical tolerance 5 µ m and surface roughness below 0.2 µ m) However, it is revealed that micro milling is 27 times faster t han micro EDM. On the contrary, the surface inspection shows that the surface realised via micro EDM seems more homogeneous. Future test s can verify if the different surfaces machined by different processes greatly impact electromagnetic performance.