A Ka-band stepped-frequency radar sensor for surface and subsurface sensing

A new millimeter-wave radar sensor employing 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 29.72-37.7 GHz. It has been used to profile the surface of a sample with range accuracy within plusmn0.1 cm. The sensor was also used to monitor continuously varying liquid level in a tank and was able to detect the displacement of liquid level with less than 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.