Video-Rate Passive Millimeter-Wave Imaging Using Phased Arrays

Passive millimeter-wave imaging technology has matured in conformance with the conventional focal-plane imaging architecture of visible light and infrared cameras. The longer wavelength at millimeter-wave frequencies allows for practical implementation of alternative pupil-plane camera architectures based on frequency-scanned phased arrays, with benefits to hardware ruggedness, form factor and cost. Challenges associated with millimeter-wave phased arrays include path matching over relatively long signal paths, and the implementation of transmission lines with extremely low loss compared to commercially available substrates. A W-band millimeter-wave phased array imager operating between 76 and 94 GHz is presented with technical performance data and examples of imagery.