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Moulla R.,University Claude Bernard Lyon 1 | Lefevre L.,CNRS System Conception and Integration Laboratory | Maschke B.,University Claude Bernard Lyon 1
Journal of Computational Physics | Year: 2012

A reduction method is presented for systems of conservation laws with boundary energy flow. It is stated as a generalized pseudo-spectral method which performs exact differentiation by using simultaneously several approximation spaces generated by polynomials bases and suitable choices of port-variables. The symplecticity of this spatial reduction method is proved when used for the reduction of both closed and open systems of conservation laws, for any choice of collocation points (i.e. for any polynomial bases). The symplecticity of some more usual collocation schemes is discussed and finally their accuracy on approximation of the spectrum, on the example of the ideal transmission line, is discussed in comparison with the suggested reduction scheme. © 2011 Elsevier Inc. Source

Vera G.A.,CNRS System Conception and Integration Laboratory | Duroc Y.,University Claude Bernard Lyon 1 | Tedjini S.,CNRS System Conception and Integration Laboratory
IEEE Transactions on Instrumentation and Measurement | Year: 2014

This paper presents a complete radio frequency identification (RFID) test platform to characterize the nonlinear effects produced by passive ultra-high frequency (UHF) RFID chips. In full operation mode, automated measurements of activation power, harmonic response level, and impedances are performed in a wide frequency range up to the fourth harmonic. The characterization method, platform composition, and operation are explained through real measurements on UHF Class-1 Generation-2 chips. A harmonic treatment is presented thanks to the joint use of an RFID tester and impedance tuners, and the effect of the antenna-chip impedance matching on the harmonic responses is compared before and after treatment. To the best of our knowledge, no similar platform has been presented in the literature. 0018-9456 © 2014 IEEE. Source

Siragusa R.,CNRS System Conception and Integration Laboratory | Lemaitre-Auger P.,CNRS System Conception and Integration Laboratory | Tedjini S.,CNRS System Conception and Integration Laboratory
IEEE Antennas and Wireless Propagation Letters | Year: 2011

An RFID-compatible focused circular phase-array antenna working at 5.8 GHz is proposed, which is theoretically analyzed and experimentally demonstrated. It consists of 24 half-wavelength dipole antennas placed on three circles. Using only two phase-shifters, a tunable focal spot in the range of 0.4-1 m (10λ) is obtained. The antenna system is analyzed using the HuygensFresnel theory, which is compared to the experimental results. At a focal distance of 0.9 m, the measured beamwidth and focal depth are given by 0.75λ and 5λ, respectively, which are in agreement with the calculated results. © 2006 IEEE. Source

Vena A.,CNRS System Conception and Integration Laboratory | Perret E.,CNRS System Conception and Integration Laboratory | Tedjini S.,CNRS System Conception and Integration Laboratory
IEEE Microwave and Wireless Components Letters | Year: 2012

This article presents a new chipless RFID tag operating in the frequency span 2 to 4 GHz. In particular the tag does not require any ground plane and it is made of 20 scatterers giving 20 b as coding capacity, for a compact size of 70×, 25 mm 2 , compatible with a credit-card format. Its fabrication process is potentially very cheap because it needs only one conductive layer, so that it can be fully printed directly on the product. To overcome the detuning effect inherent to a single layer tag and make this design robust to the environment versatility, a simple compensation technique is introduced and experimented for the first time. Measurements have been performed frequency domain, using amplitude and the group delay response. The exploitation of group delay appears to be very reliable and promising way to retrieve the coded information. © 2012 IEEE. Source

Perret E.,CNRS System Conception and Integration Laboratory | Tedjini S.,CNRS System Conception and Integration Laboratory | Nair R.S.,CNRS System Conception and Integration Laboratory
Proceedings of the IEEE | Year: 2012

This paper is mainly dedicated to the design of radio-frequency identification (RFID) tags, particularly the antennas that allow the tag to be fed, communicate, and exchange data with the reader. Good performance tags require optimized antenna that take into account numerous constraints as well as the environment of the application under consideration. Both conventional tags and robust tags are discussed. This paper also discusses how to transform a tag into an RFID sensor. © 2012 IEEE. Source

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