A Multi-Channel Focal-Plane Array Passive Imaging System Operating at 220-GHz

Passive millimeter-wave (PMMW) imaging technology has attracted significant interest in personnel security screening because of its noncontact and nonionizing radiation characteristics. In this article, a PMMW focal-plane array imaging system operating at 220 GHz is designed and implemented. The focal-plane array of the system consists of 20 single-polarization total-power radiometers. At an imaging distance of approximately 1.5 m, the system achieves a field of view of 2\times 1 m, and a full-field-of-view scan time of 3 s. Experimental results obtained from both indoor and outdoor imaging scenarios demonstrate that the system is capable of achieving a spatial resolution of 5 mm under conventional imaging conditions, and further exhibits the ability to image millimeter-scale targets under specific test conditions. These results indicate the potential of the proposed system for practical personnel security screening applications.