Selftest strategies for microwave interferometry for high-precision industrial distance measurements

Microwave interferometry is a tool for precisely measuring distances or vibrations of a target in industrial applications. Distance resolutions in the range of few micrometers and measurement value update rates of several tens of kilohertz are feasible. These parameters can only be achieved, if careful compensation of non-ideal effects is conducted. In this paper the basics of Six-Port based microwave interferometry as well as selftest techniques will be presented. Exemplarily, linearization of the operating point of the diode detectors and frequency estimation of the radar signal will be shown.