Patent application number | Description | Published |
20080237346 | SYSTEM FOR SECURE COMMUNICATION BETWEEN A CONTACTLESS CARD READER AND A CARD - The invention relates to contactless communication systems between a moving object and a reader, in particular systems in which the moving object is a chip card or an identification tag. To enhance communication security, the card reader transmits, from a radiofrequency transmission antenna separate from the main communication antenna, a disturbance signal having the same frequency and modulation type characteristics as the response signal expected from the card to the reader; the electromagnetic coupling between this separate antenna and the antenna of the reader is, however, such that the latter does not “see” the transmitted disturbance but detects only the response from the card; on the other hand, the environment between the card and the reader sees the response from the card only mixed with the disturbance signal. | 10-02-2008 |
20090291635 | RADIO-FREQUENCY COMMUNICATION DEVICE, SYSTEM AND METHOD - The invention relates to a radio-frequency communication device comprising an inductive antenna in order to communicate with a transponder. According to the invention, the antenna is capable of establishing weak coupling with a transmitter which produces a magnetic field which is substantially homogeneous on the scale of the antenna and is also capable of establishing strong inductive coupling with a transponder located in the vicinity of the device, with the device comprising a transponder interrogation circuit comprising means of sampling and processing the signal on the antenna terminals which are capable of producing a reference signal as a function of said signal; modulation means capable of modulating the reference signal; and application means capable of applying the modulated signal to the antenna terminals. | 11-26-2009 |
20100220025 | Omnidirectional flat antenna and method of production - The inventive antenna comprises a planar substrate carrying as first winding whose axis is arranged in a parallel position to the plane of the substrate. Said antenna also comprises at least one second winding, whose axis is arranged in a parallel position to the plane of the substrate and which is wound-up about a thin layer made of high magnetically permeable material and arranged in a parallel position with respect to the plane of the substrate. A third winding, whose axis is perpendicular to the first and second windings and which is wound-up about an additional thin layer can be provided. Said additional thin layer is arranged in a parallel position to the plane of the substrate and is made of high magnetically permeable material. | 09-02-2010 |
20110084796 | METHOD AND SYSTEM FOR SECURE RFID COMMUNICATION BETWEEN A NOISY READER AND A COMMUNICATING OBJECT - A method for communication between a RFID noisy reader ( | 04-14-2011 |
20120249296 | METHOD OF PROTECTION IN A CONTACTLESS RADIOFREQUENCY COMMUNICATION - A method of protection of a near-field contactless communication system against malicious attacks. The method includes exchange of information between a reader and a contactless card of duration T, measured with respect to a starting instant t | 10-04-2012 |
20120264373 | METHOD FOR DETECTION OF A CONTACTLESS RECEIVER - A method for detecting a contactless receiver in a field of an antenna of a contactless reader includes during a first ramp interval, exciting the antenna by applying a potential difference comprising a ramp between first and second values of the potential difference, and during a first plateau interval following the first ramp interval, maintaining the potential difference at the second value of the potential difference, while maintaining the potential difference at the plateau, measuring a response of the antenna, comparing the measured response and a reference response, and determining presence of a contactless receiver in the field of the antenna based at least in part on a result of the comparison. | 10-18-2012 |
20130078906 | METHOD OF SECURING A WIRELESS COMMUNICATION, RECEIVER DEVICE AND COMMUNICATION SYSTEM IMPLEMENTING THIS METHOD - A method for securing a wireless communication between a transmitter and a receiver includes: reception of a signal by the receiver; extraction by the receiver of at least one noise parameter of this signal received; comparison of the extracted noise parameter with at least one corresponding reference noise parameter stored in a memory in the receiver; decision on the presence or absence of a relay device between the transmitter and the receiver according to the result of this comparison; a preliminary calibration of the receiver, wherein: the receiver receives a signal resulting from a direct communication with the transmitter without intervention of a relay device, the receiver extracts at least one noise parameter from the signal received, and the receiver stores this noise parameter in the memory as a reference noise parameter characteristic of a direct communication without a relay device between the transmitter and the receiver. | 03-28-2013 |