A 600 GHz Imaging Radar for Contraband Detection

We have developed and demonstrated 3D imaging for contraband detection using a submillimeter-wave frequency modulated continuous wave (FMCW) radar with a fast microwave chirp and phase coherent detection. The technique provides an important advantage over more traditional CW RF imaging because of the ability to time-gate the return signals. This can be used to discern specific objects by greatly reducing clutter from unwanted targets or specular reflections. The prototype system uses a 600 GHz RF signal with a 28.8 GHz chirp producing a 2.3 MHz/μsec sweep yielding a range resolution of approximately 0.6 cm or less. Lateral resolution on the scene is set by a 40 cm diameter reflector producing approximately 0.5 cm at 4 m distance.