Electromagnetic radiation decoupler
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.
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.