Sizing of an electromagnetic transponder system for an operation in extreme proximity
a technology of electromagnetic transponder and extreme proximity, which is applied in the field of electromagnetic transponder systems, can solve the problems of loss of remote supply power, particularly vulnerable, and gap in the remote supply of transponders, and achieve the effect of reliable in time and simple implementation
Inactive Publication Date: 2006-08-03
STMICROELECTRONICS SRL
View PDF99 Cites 7 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
The present invention provides a solution for a transponder and terminal to operate in extreme proximity to each other. The invention involves a parallel oscillating circuit in the transponder that rapidly decreases its coupling coefficient with the terminal when the distance between them increases. The components of the oscillating circuit are sized to achieve this. The invention also includes a terminal that generates an electromagnetic field adapted to cooperating with the transponder. The system of contactless electromagnetic transmission between the terminal and transponder is also provided. The technical effects of the invention include improved reliability, simplicity, and efficiency in the manufacturing process.
Problems solved by technology
However, in conventional systems, the remote supply of the transponders exhibits a gap, that is, a loss of remote supply power when the transponder is very close to the terminal.
A disadvantage of this solution is that the coupling then no longer really corresponds to an extreme proximity, which makes the system particularly vulnerable to piracy by leaving a greater available range to the pirate.
A disadvantage of this solution is that, in case a pirate terminal has been designed to be able to provide a sufficient power and to be provided with a very sensitive demodulator, the transponder is then visible, even from far away, by this pirate terminal.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0034] For clarity, only those elements necessary to the understanding of the present invention have been shown in the drawings and will be described hereafter. In particular, the circuit for controlling and exploiting the oscillating circuits of the transponder and of the terminal have not been detailed.
[0035] A feature of the present invention is to provide a specific sizing of the oscillating circuit of an electromagnetic transponder so that said transponder is structurally dedicated to an operation in which it is at a distance smaller than a predetermined value from a read / write terminal, preferably, in extreme proximity, that is, at less than 1 cm.
[0036] The notion of distance to which the present invention refers is the distance separating respective antennas L1, L2 (FIG. 1) of a transponder 10 and of a terminal 1.
[0037] The present invention thus provides placing, preferably by respective sizings of the oscillating circuits of the transponder and of the antenna, the system...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
A system of contactless electromagnetic transmission between a terminal including a series oscillating circuit for generating an electromagnetic field and a transponder including a parallel oscillating circuit, these oscillating circuits being sized so that the coupling coefficient between them strongly decreases when the distance separating the transponder from the terminal becomes greater than a predetermined value.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. 119(e) to U.S. non-provisional patent application Ser. No. 09 / 615,430, filed Jul. 13, 2000, the entire contents of which are incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates to systems using electromagnetic transponders, that is, transceivers (generally mobile) capable of being interrogated in a contactless and wireless manner by a unit (generally fixed), called a read and / or write terminal. The present invention more specifically relates to transponders having no independent power supply. Such transponders extract the power supply required by the electronic circuits included therein from the high frequency field radiated by an antenna of the read / write terminal. The present invention applies to such transponders, be they read only transponders, that is, adapted to operate with a terminal only reading the transponder data, or read / write transpon...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Applications(United States)
IPC IPC(8): H04B7/00G06K7/08G06K19/07H04B1/59H04B5/00
CPCG06K7/10336G06K19/0723G06K19/07777
Inventor WUIDART, LUCENGUENT, JEAN-PIERRE
Owner STMICROELECTRONICS SRL