Design and testing of an active 190-GHz millimeter-wave imager

The design and testing of an active 190-GHz imaging system is presented. The system features two beam-scanning antennas, one of which transmits a vertical fan beam, and the other which receives a horizontal fan beam. By correlating the transmitted and received signals, an output is obtained that is proportional to the millimeter-wave reflectivity at the intersection of the two fan beams. Beam scanning is obtained by rotating a small subreflector within each antenna, allowing rapid scanning. The system has an angular resolution of 0.3 deg, a field of view of 14x14 deg, and operates at a standoff distance of 5 m. (C) 2010 SPIE and IS&T. [DOI: 10.1117/1.3514744]