Development of a new millimeter-wave integrated-circuit sensor for surface and subsurface sensing

A new millimeter-wave sensor employing the stepped-frequency radar technique has been developed using microwave and millimeter-wave integrated circuits and demonstrated for surface and subsurface sensing. The sensor is based on the coherent super-heterodyne scheme and operated from 29.72-37.7GHz. It has been used to profile the surface of a sample with range accuracy within /spl plusmn/0.1 cm. The sensor was also used to monitor continuously varying liquid levels in a tank and was able to detect the displacement of liquid level with less than /spl plusmn/0.1 cm error. The sensor successfully detected and located anti-personnel mines buried under sand with less than 1.8 and 0.2 cm of errors in horizontal and vertical directions, respectively.