Ku-Band Twisted Slotted Waveguide Antenna for Innovative "Plasma-Shaped" Cavity of Ion Sources

This paper reports about the measurements of a twisted slotted waveguide antenna, which will be used as microwave launching system for plasma heating in an innovative resonant cavity (plasma chamber) for ion sources. The proposed slotted waveguide antenna geometry is conformal to the walls of a plasma chamber, which has a peculiar shape based on the 3-D plasma spatial distribution, and in turn of the confinement magneto-static field. The complicated resulting structure has been 3-D printed using the selective laser melting (SLM) technique, which enables the possibility to fabricate complex shapes. The measured |S11| parameter and radiation patterns confirm the goodness of the achieved manufacturing tolerances and precision, validating the numerical design.