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.

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.


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

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

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

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.

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.

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.