Terasense

Prototypes 100/300 GHz

 

94 GHz Passive Imager with Mechanical Beam-Scanning

 

A 94 GHz passive imager prototype has been developed in the framework of the TeraSense project. The imaging system is based ont a Total-Power Radiometer with a mechanichal beam-scanning antenna. Figure 1 shows a photograph of the imaging system where both the radiometer and the scanning antenna are presented.


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Figure 1. Total power radiometer at 94 GHz

The main performance parameters of the system are summarized in the following points:

  • Spatial resolution: 35mm
  • Radiometric resolution: 0.3 K (70 ms integration time)
  • Integration time per pixel: Adjustable (1ms - 500 ms)
  • Scanning time: 7 minutes ( 100x50 pixels image with 70 ms integration time)

With this system, concealed objects under obscurants like clothes or luggage bags are revealed either in indoor or outdoor environments. Figure 2 shows two examples of acquired images in indoor and outdoor environments. In both environments the object is detected.

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(a)                                                                 (b)
Figure 2. Indoor (a) and outdoor (b) radiometric images acquired with the described system
The prototipe is currently finished, however further improvements with the main effort focused to reduce acquisition time is going to be introduced in the design.
92 GHz Frequency- Modulated Continuous-Wave Radar
A Frequency Modulated Continuous Wave (FMCW) radar at 92GHz is being developed. Experimental measurements have been performed in order to assess the capabilities of the system.

 

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Fig.3. System instrumentation setup for deformation (left)  and  surface relief imaging (right).

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Fig.4. Pictures of  front and back scene under test on the left, and deformation interferometric image on the right.

 

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Fig.5. (a) Picture of the scenario under test. (b) Detail of the target to be detected.

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Fig.6.  relief interferometric images.

 

100 GHz Near Field Imaging System

A near field imaging system for THz tomographic imaging based on a retina is being studied. This system will allow performing real time imaging.

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Fig. 7 (Left) Near Field imaging system. (Right) Fabricated retina of 8 slot elements with a PIN diode

 

300 GHz Radar for Environmental Remote Sensing

A radar at 300 GHz is being developed for the study of the attenuation due to atmospheric gas and clouds. The objective is to design, fabricate and test an all-solid-state active sub-millimeter imager that utilizes the swept-frequency FMCW radar technique to map a target in three dimensions with centimeter-scale resolution in both range and cross range.

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Fig. 8 (Left) Photograph of the horn-antenna target located on the turntable platform
(Right) ISAR image of the horn-antenna target obtained from the data measured by the radar prototype.