3D microwave imaging system for the remote detection and reading of passive sensors

This communication describes the use of a 3D microwave active imaging system based on a Frequency-Modulated Continuous-Wave radar for the wireless localization, identification and reading of passive (battery-less) and chipless electromagnetic sensors. The beam scanning of the scene is performed mechanically and allows detecting passive sensors from the visualization of 3D microwave image of a scene. A preliminary imaging system demonstrator operating at 24GHz is briefly described and resulting 3D images are reported for different scenarios. A dynamic of 5.9 dB for the sensing mode echo level is observed for a passive sensor located at 4.5 meters from the radar. An approach of the maximal density of detectable passive sensors is also given.