Active imaging systems in the millimeter wave region have proven to offer good results for security applications. Especially a coherent signal detection results in a high dynamic range. Several techniques and systems were published in the last years. The drawback of an active illumination of the measurement object is the effect of shading and poor illuminated areas due to specular reflections from smooth surfaces. The visibility of an object depends on its surface roughness and its relative positioning to the imaging sensor. Especially in personnel screening, the human skin behaves as a smooth mirror for millimeter waves. This paper describes the incorporation of multipath signals in the imaging process to enhance the illumination properties of active imaging systems. The proposed multipath concept is demonstrated with an active multistatic imaging system working from 70 to 80 GHz for security applications.

Date Published: 7 October 2014
PDF: 7 pages
Proc. SPIE 9252, Millimetre Wave and Terahertz Sensors and Technology VII, 925205 (7 October 2014); doi: 10.1117/12.2067266

Published in SPIE Proceedings Vol. 9252:
Millimetre Wave and Terahertz Sensors and Technology VII
Neil Anthony Salmon; Eddie L. Jacobs, Editor(s)