Development of a passive millimeter-wave imaging system

Millimeter-wave imaging systems are currently being developed for a wide range of applications, including remote sensing, all-weather aircraft landing, and concealed weapon detection. In this paper, we designed and tested of the passive millimeter-wave imaging system using focal plane approach. The proposed system consists of two parts. The first part is a 94 GHz band millimeter imaging part which is coupled to a dielectric lens, a horn antenna, two low noise amplifiers, and a diode detector. The second part is a control part. The control part consists of 2-axes Cartesian robots, and a 16-bit data acquisition (DAQ). The 2-axes Cartesian robot should be able to scan a 2-D image of the scene, with a raster scanning method. The passive millimeter-wave image of 50 times 50 pixels is acquired, and is immediately displayed and stored for post processing. The experimental results are presented to demonstrate the feasibility of the passive millimeter-wave imaging system. In order to improve the image quality, interpolation methods are applied.