This article describes the wireless and simultaneous interrogation and identification of multiple passive (zero-power) pressure sensors in an industrial environment with a reading range of at least 4 m. The 3-D beamscanning of the scene is performed from a 24-GHz frequency-modulated continuous-wave (FM-CW) radar and for diverse electric field polarizations. The identification is performed using a k-nearest neighbor classification. The benefit of using the cross-polarized electric fields combined with a radar imagery technique is enlightened from the analysis of the background clutter and the simultaneous remote interrogation of several passive pressure sensors at a distance up to 17.7 m. The measurement uncertainty on pressure obtained from the proposed long-range wireless technique is finally reported and discussed.

In this paper, we report the remote measurement of the pressure from the Radar interrogation of a novel microfluidic passive sensor. This sensor includes a microfluidic band-pass filter, whose transmission coefficient in the Ka-band depends on the applied pressure, and two cross-polarized Rx- and Tx-antennas connected to the terminals of the filter for enhancing the full-scale measurement range of the sensor's Radar echo level. The filter is 3D-printed via the Sintering Laser Melting technique. For a Radar-to-sensor distance of 3 meters, a high full-scale measurement range of 8dB on the echo level is reported with a measurement sensitivity of 0,03dB/mbar for applied pressure ranging from 350 mbar to 640 mbar.

This paper describes the wireless and simultaneous interrogation of multiple passive (zero-power) pressure sensors in an industrial environment with a reading range of at least 3 meters. The 3D beamscanning of the scene is performed from a 24GHz FM-CW radar and for diverse electric field polarizations. The benefits of using the cross-polarized electric fields combined with a radar imagery technique are enlightened from the analysis of the ambient clutter and the simultaneous remote interrogation of two passive pressure sensors. The measurement uncertainty on pressure obtained from the proposed long-range wireless technique is finally reported and discussed.

This paper describes a new wideband-enabling frequency converter topology based on N-path circuits. A model of the N-path frequency converter, derived from the N-path theory, is proposed. It can predict both conversion gains and the output spectrum, and explain unwanted harmonics as well. The operating principle is validated by an integrated circuit (IC) fabricated in 130nm BiCMOS technology, exhibiting a minimum 185-MHz bandwidth over a 0.5-1.5 GHz clock frequency range.

This paper reports a new method for the identification of chipless sensors based on 3D radar imagery and polarimetry. Chipless pressure sensors are wirelessly interrogated in a highly reflective environment with a 24GHz FM-CW radar. A novel algorithm of identification based on the 3D distribution of radar echoes is proposed and applied to mitigate the clutter and identify multiple chipless pressure sensors. The electromagnetic footprint of each sensor is defined and advantageously used for identification purposes.

For testing satellites before launching, multiple wired sensors are commonly used for covering the metallic walls of the inner satellite structure. In order to reduce the maintenance cost of such Structure Health Monitoring platform, wireless sensors could be advantageously used. In this paper, we demonstrate the reading feasibility of passive and wireless millimetre-wave sensors embedded inside an over-sized metallic box. The box simulates here a part of the electromagnetic reverberant environment within satellite structure. In the proposed cross-polarized configuration, a dual-polarized passive repeater is used for transmitting inside the box the co-polarized electric field radiated by a Frequency-Modulated Continuous-Wave 24GHz radar. This repeater is also used for transmitting outside the box the cross-polarized electric field radiated by a depolarizing sensor. The proof-of-concept is established here from a passive and chipless pressure sensor, but other types of wireless sensors may be used as well.

This paper reports the reading of passive and chipless millimeter-wave sensors using a dual-polarized through-wall repeater. The reader is here a millimeter-wave frequency-modulated continuous-wave (FMCW) Radar, and the batteryless sensor corresponds to a chipless sensing device whose cross-polarized electromagnetic reflectivity depends on the applied pressure. The proposed dual-polarized repeater allows transmitting two different and orthogonal electric field polarizations. The feasibility of through-wall reading of sensors is demonstrated here at 24 GHz from a passive pressure sensing device.