Electromagnetic radiation decoupler

• US 9,104,952 B2
• Filed: 09/28/2012
• Issued: 08/11/2015
• Est. Priority Date: 06/25/2005
• Status: Active Grant

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Omni-Id Cayman Limited (Assa Abloy AB)
• Inventors: Lawrence, Christopher Robert, Clarke, Paul Richard, Brown, James Robert, Damerell, William Norman
• Primary Examiner(s): La, Anh V
• Application Number:
  US13/630,614
• Publication Number:
  US 20140117093A1
• Time in Patent Office: 1,047 Days
• Field of Search: 3405721-5729, 340/10.1, 340/10.6, 235380-385, 235/451, 235/487, 235/488, 235/492
• US Class Current: 1/1
• CPC Class Codes: G06K 19/07 with integrated circuit chips
• CPC Class Codes: G06K 19/07722 the record carrier being multilayered, e.g. laminated sheets flat articles in general, see B32B37/00
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/0776 the adhering arrangement being a layer of adhesive, so that the record carrier can function as a sticker
• CPC Class Codes: G06K 19/07771 the record carrier comprising means for minimising adverse effects on the data communication capability of the record carrier, e.g. minimising Eddy currents induced in a proximate metal or otherwise electromagnetically interfering object

Abstract

An electromagnetic radiation decoupler for decoupling radiation in the wavelength range λ_min to λ_max. The decoupler has a first conductor layer in contact with a dielectric layer which comprises at least one area of absence and the thickness of the decoupler is less than λ_min/4n, where n is the refractive index of the dielectric. The dielectric layer may be sandwiched between two conductor layers, one of which has the structure described above. The invention is also directed to methods of using and various articles comprising such a decoupler.

Claims

1. A decoupled RFID tag comprising at least one dielectric layer sandwiched between at least one first conductor layer and at least one second conductor layer, wherein the at least one first conductor layer has at least one area of absence where the first conductor layer does not overlie the dielectric layer and the decoupler is adapted such that, in use, an incident electromagnetic field is enhanced in the vicinity of the area of absence of the first conductor layer wherein the electronic device is an RF tag and wherein the RF tag is located in the vicinity of the area of absence of the first conductor layer.

2. The decoupled RFID tag of claim 1 wherein the RF tag is electrically isolated from said first conductor layer.

3. The decoupled RFID tag of claim 1 wherein the dielectric layer is formed from a material selected from the group consisting of a plastic, polymer, ceramic, glass, cardboard, corrugated cardboard, paper, substantial void or combinations thereof.

4. The decoupled RFID tag of claim 3 wherein the dielectric layer is formed from a ceramic.

5. The decoupled RFID tag of claim 1 wherein the tag includes two or more area of absences.

6. The decoupled RFID tag of claim 1 wherein the area of absence is selected from the group consisting of one or more discrete crosses, one or more L-shapes, one or more rectilinear channel, one or more curvilinear channel, one or more grooves, one or more voids or combinations thereof.

7. The decoupled RFID tag of claim 1 wherein the area of absence is filled with a non-conducting material.

8. The decoupled RFID tag of claim 1 wherein the area of absence if filled with a further dielectric core layer material.

9. The decoupled RFID tag of claim 1 wherein a protective housing covers the decoupler.

10. A decoupled RFID tag comprising at least one ceramic dielectric layer sandwiched between at least one first conductor layer and at least one second conductor layer, wherein the at least one first conductor layer has at least one area of absence where the first conductor layer does not overlie the dielectric layer and the decoupler is adapted such that, in use, an incident electromagnetic field is enhanced in the vicinity of the area of absence of the first conductor layer wherein the electronic device is an RF tag and wherein the RF tag is located in the vicinity of the area of absence of the first conductor layer.

11. The decoupled RFID tag of claim 10 wherein the RF tag is electrically isolated from said first conductor layer.

12. The decoupled RFID tag of claim 10 wherein the tag includes two or more area of absences.