340 GHz and 250 GHz Schottky Solid-state Heterodyne receiver arrays for Passive Imaging Systems

Two four-pixel receiver arrays for operation in 340 and 250 GHz passive imaging system are presented. The millimeter-wave front-end components and THz mixer are achieved by the planar GaAs Schottky-barrier varactor to obtain good performance in room temperature while lowering the cost and difficulty compared to integrated circuit. The discrete 340GHz and 250GHz mixers have the lowest DSB noise temperature of 1020K and 900K respectively within the operation band. A broadband IF bandwidth, 20GHz, is adopted in passive imaging systems for increasing the received human body radiation power. Good detection performance and space resolution is still obtained for object distances 3-8m. Compared to the current sensors operated in cryogenic imaging system, the receiver array is a cheap and feasible method for personal security screening.