Whole-microwave system modeling for brain imaging

In this paper, we present the results of a whole-system modeling of a microwave measurement prototype for brain imaging, consisting of 160 ceramic-loaded antennas working around 1 GHz. The modelization has been performed using open source FreeFem++ solver. Quantitative comparisons were performed using commercial software Ansys-HFSS and measurements. Coupling effects between antennas are studied with the empty system (without phantom) and simulations have been carried out with a fine numerical brain phantom model issued from scanner and MRI data for determining the sensitivity of the system in realistic configurations

Offset reflectarray fed by a printed source

International audienceThis paper presents the design of an offset reflectarray illuminated by a printed primary source. The proposed build-up is compatible with flip-chip technology, enabling a direct connection between the RFIC and the antenna source. Measurements are realized using a GSG RF probe and a good agreement is obtained with simulated dat

Conception d’un radar imageur très haute résolution en fréquence millimétrique

National audienceLa sécurité des lieux publics est devenu une problématique centrale pour les états. Un des principaux défis pour choisir une solution, est de trouver le bon compromis entre son temps de mise en œuvre et l’acceptabilité par le citoyen. Ce papier propose la conception d’un radar imageur très haute résolution en fréquence millimétrique. De premières études sont menées pour réduire le nombre de points de mesure sans dégrader la qualité de l’image afin d’accélérer le temps d’acquisition

Dual Frequency Processing of Subsampled Measurements in W-band

International audienceNowadays, mm-waves are targeted for numerous applications, among which security ones. With the increasing threats of attacks all over the world, concealed objects detection has become a major concern. Systems already exist but they need to be improved for the upcoming requirement of imaging a moving crowd. Having a real-time image is one of the serious challenges for system’s completion. Measurement time is an issue that we endeavor to drastically reduce. We image an object with subsampled measurements and the real-time back-propagation algorithm (BPA). The on measurements points compression rate is 95%. BPA intrinsically requires a high number of spatial measurements points to avoid grating lobes in the image, which makes the subsampling impracticable. We make use of a dual frequency processing to overcome this difficulty. The processing was tested on measurements taken at 77 and 94 GHz and results show a good grating lobe suppression. Few years ago, the practical implementation of this dual frequency technique would have been an issue but the increasing developments of systems at mm-Waves makes it easier