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Limoges, France

Bernard A.,XLIM | Gama N.,National Engineering School of Caen
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

We present a variant of the Lagrange-Gauss reduction of quadratic forms designed to minimize the norm of the reduction matrix within a quadratic complexity. The matrix computed by our algorithm on the input f has norm , which is the square root of the best previously known bounds using classical algorithms. This new bound allows us to fully prove the heuristic lattice based attack against NICE Cryptosystems, which consists in factoring a particular subclass of integers of the form pq 2. In the process, we set up a homogeneous variant of Boneh-Durfee-HowgraveGraham's algorithm which finds small rational roots of a polynomial modulo unknown divisors. Such algorithm can also be used to speed-up factorization of pq r for large r. © 2010 Springer-Verlag Berlin Heidelberg. Source


Carsenat D.,MINACOM | Crunteanu A.,MINACOM | Chatras M.,MINACOM | Passerieux D.,XLIM
IEEE Antennas and Wireless Propagation Letters | Year: 2015

Surface acoustic wave (SAW) filters have been developed to code the information received by an antenna array and sum them into a single signal. In post-processing, these waveforms are retrieved exploiting the orthogonal propagation in each SAW filter. Thus, a proof a concept of beamforming and imaging using SAW filters is presented. © 2002-2011 IEEE. Source


Casagrande R.,GERAC | Maurice O.,GERAC | Reineix A.,XLIM
IEEE International Symposium on Electromagnetic Compatibility | Year: 2013

The purpose of the paper is to model cable bundles in the high frequency range. The principle of the model is based on the combination of the Vabre's and Branin's equations. The calculation uses the Kron's method applied to EMC. The calculation results are checked by experimental tests. © 2013 EMC Europe Foundation. Source


Toubet M.S.,XLIM | Chantalat R.,XLIM | Hajj M.,CISTEME | Jecko B.,CISTEME | Diot J.C.,CEA Cesta
Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012 | Year: 2012

In this paper, we present a Wide Bandwidth (71%), ultra Low-Profile (<λ/10) and High-Gain (17 dB) EBG antenna which is used for high power and electronic warfare applications. A prototype of this modelized antenna is manufactured and the measured performances are compared to the simulated ones. © 2012 IEEE. Source


Hamani R.,NXP Semiconductors | Andrei C.,NXP Semiconductors | Jarry B.,XLIM | Lintignat J.,XLIM
IEEE International Conference on Microelectronic Test Structures | Year: 2014

This paper, presents a novel methodology for small signal equivalent circuit extraction suitable for high frequency characterization up to mm-wave range. This methodology allows the de-embedding and the extraction of RF characteristics by the use of a smart matching at 50Ω of the transistor connected in GSG probe pads. The method has been validated first on a test module based on RFMOS transistor fabricated in BiCMOS 0.25μm technology from NXP Semiconductors. The results of matched RFMOS transistors at 30.5GHz are presented here and show good agreement between measurements/extractions and calculations (e.g. for Cgs). Second, a bipolar transistor matched test structure is investigated. An improvement of transmission gain of matched test structured from-12dB to-0.2dB has been found using measurements and simulated data. © 2014 IEEE. Source

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