Non-destructive permittivity measurement of thin dielectric sheets

The space observation radar TIRA (Tracking and Imaging Radar) is a system unique in Europe: The system primarily serves as the central experimental facility for development and investigation of radar techniques for the detection and reconnaissance of objects in space. TIRA also provides valuable support for space missions: space agencies from all over the world use the special capabilities of the Fraunhofer scientists and their system. Due to the recent renewal of the radome, it was required that the quality and electromagnetic properties of the radome panel material was verified before mounting. The present article describes a measurement method based on a split rectangular cavity attached to a specially fabricated fixture. The theoretical background, the mechanical design will be described and several measurement results will be shown.