Materials characterization and defect detection with millimeter wave radar sensor in near field

A test system based on a microwave sensor which works with frequency modulated continuous waves radar principle (FMCW radar) at a frequency of 94 or 77 GHz has been developed. The sensor works nondestructively and can be used in contactless way. The distances between sensor and test object are in the range of some cm to some m. The potential industrial applications are manifold: they encompass materials characterization, defect detection and online process monitoring, e.g. injection moulding process of plastics with gas injection technique (GIT).