Proceedings Article | 7 October 2014
Proc. SPIE. 9252, Millimetre Wave and Terahertz Sensors and Technology VII
KEYWORDS: Staring arrays, Mirrors, Extremely high frequency, Millimeter wave imaging, Modulation, Imaging systems, Sensors, Video, Lamps, Plasma
In recent years, much effort has been invested to develop inexpensive but sensitive Millimeter Wave (MMW) detectors
that can be used in focal plane arrays (FPAs), in order to implement real time MMW imaging. Real time MMW imaging
systems are required for many varied applications in many fields as homeland security, medicine, communications,
military products and space technology. It is mainly because this radiation has high penetration and good navigability
through dust storm, fog, heavy rain, dielectric materials, biological tissue, and diverse materials. Moreover, the
atmospheric attenuation in this range of the spectrum is relatively low and the scattering is also low compared to NIR
and VIS. The lack of inexpensive room temperature imaging systems makes it difficult to provide a suitable MMW
system for many of the above applications. In last few years we advanced in research and development of sensors using
very inexpensive (30-50 cents) Glow Discharge Detector (GDD) plasma indicator lamps as MMW detectors. This paper
presents three kinds of GDD sensor based lamp Focal Plane Arrays (FPA). Those three kinds of cameras are different in
the number of detectors, scanning operation, and detection method. The 1st and 2nd generations are 8 × 8 pixel array and
an 18 × 2 mono-rail scanner array respectively, both of them for direct detection and limited to fixed imaging. The last
designed sensor is a multiplexing frame rate of 16x16 GDD FPA. It permits real time video rate imaging of 30 frames/
sec and comprehensive 3D MMW imaging. The principle of detection in this sensor is a frequency modulated
continuous wave (FMCW) system while each of the 16 GDD pixel lines is sampled simultaneously. Direct detection is
also possible and can be done with a friendly user interface. This FPA sensor is built over 256 commercial GDD lamps
with 3 mm diameter International Light, Inc., Peabody, MA model 527 Ne indicator lamps as pixel detectors. All three
sensors are fully supported by software Graphical Unit Interface (GUI). They were tested and characterized through
different kinds of optical systems for imaging applications, super resolution, and calibration methods. Capability of the
16x16 sensor is to employ a chirp radar like method to produced depth and reflectance information in the image. This
enables 3-D MMW imaging in real time with video frame rate. In this work we demonstrate different kinds of optical
imaging systems. Those systems have capability of 3-D imaging for short range and longer distances to at least 10-20
meters.
