Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
  • H01Q1/526—Electromagnetic shields
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K9/00—Screening of apparatus or components against electric or magnetic fields
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
  • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
  • G06K19/073—Special arrangements for circuits, e.g. for protecting identification code in memory
  • G06K19/07309—Means for preventing undesired reading or writing from or onto record carriers
  • G06K19/07318—Means for preventing undesired reading or writing from or onto record carriers by hindering electromagnetic reading or writing
  • G06K19/07327—Passive means, e.g. Faraday cages
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K9/00—Screening of apparatus or components against electric or magnetic fields
  • H05K9/0073—Shielding materials
  • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
  • H05K9/0088—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising a plurality of shielding layers; combining different shielding material structure

Definitions

• RFID Radio frequency identification devices
• RFID carry data or information that can be accessed by a corresponding receiver.
• RFID creates an automatic way to collect information about a product, place, time or transaction quickly, easily and without human error. It provides a contactless data link, without need for line of sight or concerns about harsh or dirty environments that restrict other auto ID technologies such as bar codes.
• RFID is more than just an ID code, it can be used as a data carrier, with information being written to and updated as necessary or appropriate.
• the data or information carried and stored within RFID may be susceptible to dissemination and capture by persons not otherwise authorized to receive the data or information. Such unauthorized capture or receipt of RFID data or information presents a problem for those wishing to carry and store data or information safely within RFID.
• a shielding article including a substantially conductive layer; and a substantially magnetically permeable layer adjacent the conductive layer.
• Embodiments of the invention can feature the substantially conductive layer and the substantially magnetically permeable layer as collectively providing electromagnetic shielding characteristics to prevent unauthorized or undesired capture or receipt of data.
• Embodiments of the invention provide effective shielding when provided on one side of an RFID or when surrounding the RFID.
• the method includes disposing an apparatus including a radio frequency information component adjacent the conductive layer of the article.
• the method also includes shielding electromagnetic communication between the radio frequency information component and an external device.
• the method also includes preventing unauthorized release of information from the radio frequency information component.
• FIGS. 1 and 2 illustrate two embodiments of a shielding article and external device according to an embodiment of the invention.
• FIGS. 3 and 4 illustrate two embodiments of a shielding article and a cover and external device according to another embodiment of the invention.
• FIG. 5 is a graph illustrating a shielding effectiveness curve corresponding to an embodiment of the invention.
• FIG. 6 is a graph illustrating a magnetic permeability curve corresponding to an embodiment of the invention.
• the present invention includes a multi-layer shielding article 15 that is useful for shielding radio frequency identification devices by interfering with or cutting off the electrical or magnetic radio frequency detecting signal emitted from electromagnetic equipment, electronics equipment, receiving devices, or other external devices.
• Embodiments of the multi-layer shielding article 15 can include a substantially conductive layer 25, and a substantially magnetically permeable layer 35 adjacent the substantially conductive layer 25 that operate to shield or otherwise protect a radio frequency information component 40.
• the substantially conductive layer 25 can include, for example, a high conductivity layer. Such a layer may be made from a metal such as a copper material, for example. Examples of the copper material can include a thickness of about 0.08 mm.
• the copper or other conductive material can have a surface resistance of up to about 0.1 ohm/in 2' In one exemplary embodiment, the copper or other conductive material can have a surface resistance of up to about 0.05 ohm/in 2 . In another exemplary embodiment, the copper or other conductive material can have a surface resistance up to about 0.005 ohm/in 2 .
• the surface resistance when reported herein, including the claims, can be measured by placing a sample of conductive material between two gold plated electrodes, each electrode being 1 inch by 1 inch square, with a 2 kg force applied to compress the sample between the electrodes. A DC constant current of 100 mA is applied, and the voltage between the electrodes is measured.
• the conductive layer 25 and the magnetically permeable layer 35 are adjacent each other.
• examples can include having a conductive or nonconductive adhesive of a thickness about 0.03 mm interposed between the conductive layer 25 and the magnetically permeable layer 35.
• embodiments of the conductive layer 25 and the magnetically permeable layer 35 can optionally be collectively wrapped with a layer of conductive fabric.
• the conductive layer 25 is closer to the RRID 40.
• the magnetically permeable layer 35 is closer to the RFID 40.
• the RFID 40 is between the external device 60 and the shielding article 15.
• the shielding article is between the RFID 40 and the external device 60. This leaves one side of the component 40 substantially free of the conductive and magnetically permeable layers in the direction away from the external device 60.
• the shielding article 15 substantially surrounds the RFID 40.
• the portion of the cover 50 that is between the RFID 40 and the external device 60 is substantially free of the conductive layer and the magnetically permeable layer.
• the portion of cover 50 that is substantially free of the shielding article 15 may optionally be see through to allow visual inspection of the component 40.
• Embodiments of the conductive layer 25 and the magnetically permeable layer 35 of the shielding article 15 can collectively provide electromagnetic shielding characteristics sufficient to prevent unauthorized or undesired capture or receipt of data.
• Embodiments of the invention provide effective shielding when provided on one side of an RRID or when surrounding the RFID.
• the shielding article 15 When the shielding article 15 is provided on only one side of the RRID it can be effective between an external device 60 and the component 40, and it can be effective when the component 40 is between the external device 60 and the shielding article 15.
• the shielding article is on the opposite side of component 40 from the external device 60, it provides electromagnetic shielding as follows.
• the external device 60 attempts to capture information from the component 40 by reflecting a radio signal to and from the component 40
• the shielding device 15 even when behind the device 40, also reflects the radio signal back to the device 60. It is this additional reflected signal that interferes with the ability of the external device 60 to be able to get a useful reflected signal from the device 40.
• One useful method for measuring the effectiveness of the shielding article is provided in China Military Standard SJ20524-1995 (ASTM D4935-99).
• the substantially conductive layer 25 and the substantially magnetically permeable layer 35 of the multilayer shielding article 15 collectively prevent magnetic and/or electromagnetic signal penetration from an external device 60 to the radio frequency information component 40.
• an apparatus including a radio frequency information component 40 is disposed or placed adjacent the conductive layer 25 of the multi-layer shielding article 15.
• the component 40 may optionally be placed adjacent the magnetically permeable layer 35.
• Examples of the apparatus 40 can include an identification card, an information card, an insurance card, a staff timecard, a smart-card, or any other type apparatus that might carry or store data or information.
• the radio frequency information component 40 should be placed reasonably close to the conductive layer 25 of the multi-layer shielding article 15.
• the distance between the conductive layer 25 of the shielding article 15 and the radio frequency information component 40 can be approximately 0.2
• the shielding article 15 can cover both or all sides of the radio frequency information component 40.
• FIG 3 shows an embodiment where the multilayer shielding article 15 covers both sides of the apparatus containing the radio frequency information component 40.
• a cover 50 for protection of the article 15 can surround the shielding article 15 during its use or operation.
• the cover 50 for example, can be in the form of a wallet, handbag, folder, or other carrying device as understood by those skilled in the art.
• the cover 50 may be substantially free of the magnetically permeable layer and the conductive layer.
• the cover 50 may optionally be clear to allow visual inspection of one side of the radio frequency identification component 40.
• the shielding article 15 can effectively shield the radio frequency information component 40 while only covering one side of the radio frequency information component 40.
• the multi-layer shielding article 15 can effectively shield electromagnetic communications between the radio frequency information component 40 and an external device 60, thereby preventing unauthorized release of information from the radio frequency information component 40.
• the radio frequency information component 40 can be removed from the multi-layer shielding article 15 structure (e.g., wallet), thereby allowing data or information to be released from the radio frequency information component 40 to the authorized user.
• the shielding article 15 was tested via a test method applied to the measurement of shielding effectiveness and magnetic permeability of planar materials under normal incidence, far-field, plane-wave conditions.
• the article 15 can shield the radio frequency information component 40 to produce a shielding effectiveness of greater than 80 dB @ 10MHz, as shown in Figure 5.
• the article 15 can shield the radio frequency information component 40 to produce a shielding effectiveness of greater than 80 dB @ 5GHz.
• the article 15 can shield the radio frequency information component 40 to produce a shielding effectiveness greater than 80 dB anywhere within the frequency range of 10MHz to 5GHz.
• Figure 5 shows that the shielding effectiveness can exceed 100 dB through a wide range of frequency.
• the shielding effectiveness is defined as the ratio of received power with use of the article 15 to received power without use of the article 15.
• the article 15 can also shield the radio frequency information component 40 to produce a desirable magnetic permeability and relative magnetic permeability, as understood by those skilled in the art.
• the article 15 can shield the radio frequency information component 40 to produce a relative magnetic permeability greater than 30,000 at 50 Hz, greater than 60, 000 at 50Hz, or greater than 100,000 @ 50 Hz (relative permeability ⁇ r is a unitless value resulting from magnetic permeability ( ⁇ ) divided by vacuum permeability ( ⁇ O), as understood by those skilled in the art).
• Figure 6 shows the curve for one example or embodiment of the magnetic features of the shielding article 15.
• the Y-axis represents magnetic flux density with units of mT, and the X-axis represents magnetic strength with units of A/m.
• the shielding article 15 can advantageously produce various shielding conditions as measured by China Military Standard SJ20524-1995 (ASTM D4935-99).
• the substantially conductive layer 25 and the substantially magnetically permeable layer 35 of the multi-layer shielding article 15 collectively prevent magnetic and/or electromagnetic signal penetration from an external device 60 to the radio frequency information component 40.
• the multi-layer shielding article 15 can advantageously prevent data or information from being stolen or otherwise detected by unauthorized users.
• the multi-layer shielding article 15 can frustrate, impede, and obstruct an attempt to acquire or capture such data or information from the radio frequency information component 40 by substantially cutting off any magnetic and/or electromagnetic detecting signals emitted from the equipment, and /or by reflecting back the detecting signals emitted from the external equipment 60.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Computer Hardware Design (AREA)
• Computer Security & Cryptography (AREA)
• Power Engineering (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
• Burglar Alarm Systems (AREA)
• Laminated Bodies (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (8)

Cited By (4)

Families Citing this family (13)

Citations (4)

Family Cites Families (9)

• 2007
  • 2007-01-25 CN CNA2007100072118A patent/CN101231707A/zh active Pending
• 2008
  • 2008-01-09 BR BRPI0808659-1A patent/BRPI0808659A2/pt not_active IP Right Cessation
  • 2008-01-09 MX MX2009007867A patent/MX2009007867A/es active IP Right Grant
  • 2008-01-09 US US12/523,139 patent/US20100014270A1/en not_active Abandoned
  • 2008-01-09 JP JP2009547343A patent/JP2010517305A/ja active Pending
  • 2008-01-09 KR KR1020097016876A patent/KR20090104863A/ko not_active Withdrawn
  • 2008-01-09 WO PCT/US2008/050549 patent/WO2008091734A1/en not_active Ceased
  • 2008-01-09 EP EP08705783.2A patent/EP2118964A4/en not_active Withdrawn

Patent Citations (4)

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