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Le Bourget-du-Lac, France

Perret E.,Grenoble Institute of Technology | Hamdi M.,University of Savoy | Vena A.,Grenoble Institute of Technology | Garet F.,University of Savoy | And 3 more authors.

This article presents two chipless RFID approaches where data are reading using electromagnetic waves and where the medium encoding the data is completely passive. The former approach rests on the use of RF waves. The tags are comparable with very specific, planar, conductive, radar targets where the relation between the tag geometry and its electromagnetic signature is perfectly known and is used to encode the data. The data storage capacity of the RF chipless tags is proportional to of the used frequency bandwidth. As radio spectrum is regulated, the number of possible encoding bits is thus strongly limited with this technology. This is the reason why we introduce a new family of tags radically different from the preceding one, where data is encoded in volume thanks to a multilayer structure operating in the THz domain. These two approaches although different are complementary and allow to increase significantly the data storage capacity of the chipless tags. Simulation and experimental results are reported in this paper for both configurations. We demonstrate a coding capacity of 3.3 bit/cm2 for RFID chipless tags and a potential 10 bits coding capacity in the THz domain. Source

Ayde R.,University Claude Bernard Lyon 1 | Gaborit G.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Jarrige P.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Duvillaret L.,KAPTEOS | And 3 more authors.
IEEE Sensors Journal

In this paper, we demonstrate the use of a LiTaO3 crystal associated with a typical nuclear magnetic resonant loop coil to perform an optically remote radio frequency magnetic-field characterization. The whole transduction scheme is theoretically and experimentally studied. The measurement dynamics reaches 60 dB. The minimum detectable magnetic field is lower than 1 nT, which corresponds to an induced inner crystal electric field as low as 30 mV/m. To evaluate the spatial potentialities of the sensor, a 1-D mapping of the field along an asymmetric butterfly-shaped loop coil is performed. The result is in good agreement with finite-difference time-domain simulations and demonstrates the vectorial behavior of the sensor device. © 2001-2012 IEEE. Source

Guyot C.,CNRS Femto ST Institute | Ulliac G.,CNRS Femto ST Institute | Dahdah J.,KAPTEOS | Qiu W.,CNRS Femto ST Institute | And 3 more authors.
Optics Letters

In this Letter, we report a technique to etch giant aspect ratio nanostructures in lithium niobate. An 8 μm long Bragg grating on a Ti:LiNbO3 ridge waveguide was fabricated by combining optical-grade dicing and focused ion beam milling. The reflectivity was evaluated using an optical coherence tomography system: it is measured to be 53% for the TM wave and 47% for the TE wave. We study by 2D-FDTD the modeled behavior of the electromagnetic field when an angle exists between two consecutive sidewalls of the grating in order to understand the difference between ideal Bragg grating and experimental samples. These simulations allow us to optimize the parameters in order to increase the reflection of the grating up to 80%. © 2014 Optical Society of America. Source

Gaborit G.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Jarrige P.,KAPTEOS | Lecoche F.,KAPTEOS | Dahdah J.,KAPTEOS | And 3 more authors.
IEEE Transactions on Plasma Science

In this paper we illustrate the ability of electrooptic sensors to perform electric (E)-field vectorial measurements. Thanks to their frequency response spreading over nine decades and to their measurement dynamics reaching 120 dB, these sensors are of high interest for some applications (near field mapping, energy line monitoring, electromagnetic compatibility, and so on). Furthermore, due to their fully dielectric structure and millimetric size, almost no perturbation is induced on the E-field to be measured, even in the near field region. This paper is focused on high-intensity pulsed E-field characterization in different environments such as air, water (bioelectromagnetism applications), or plasmas (in situ assessment of the E-field associated to an electric discharge and to the induced plasma). The use of such a technology for electrical equipment and energy line monitoring is also investigated. © 1973-2012 IEEE. Source

Gillette L.,University of Savoy | Gaborit G.,University of Savoy | Grau A.,Electricite de France | Dahdah J.,KAPTEOS | And 2 more authors.
33rd Electrical Insulation Conference, EIC 2015

We present herein a compact voltage clamp for measuring electric field in monoconductor and multiconductors cables. The clamp exploits electro optic (EO) principle to diagnostic low or high voltage equipment. This device allows to measure electric field surrounding a multiwires power cable and permits to deduce amplitude, phase and location of each conductors in a cable. The field has been firstly theoretically investigated and numerically computed. The experiments validate the sensor performances such as dynamics and temporal resolution in an actual industrial environment. © 2015 IEEE. Source

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