Imaging and sensing from 100GHz to 1THz

This paper discusses the merits of different antenna designs for security applications when operating in the 100 GHz to 1 THz region. Designs are required which are lightweight with an f/number of ~1 and mirror systems are preferred. Lenses have been used for smaller systems (150 mm diameter) but the mass and loss are prohibitive for larger diameters. The propagation of radiation through the atmosphere, clothing and explosive impacts on performance and is also reviewed. Two systems are described both operating at 100 GHz; one is an imager based on mirrors and the other a sensor based on lenses.