RFID devices with multi-frequency antennae
View Patent ↗An RFID device includes a conductive sheet defining at least first and second portions, with an intermediate portion joining the other portions. One or more RFID chips electrically coupled to the portions, such as one or both of the first and second portions of the conductive sheet and to the intermediate portion. The first portion of the conductive sheet defines a multi-turn high frequency antenna having one or more disruptions in the conductive sheet positioned between and/or defining adjacent turns of the multi-turn antenna. The second portion of the conductive sheet defines a first radiating arm of an ultra high frequency antenna. The disruptions direct a high frequency current around the turns of the multi-turn high frequency antenna, while allowing an ultra high frequency current to flow across the disruptions, resulting in the first portion of the conductive sheet defining a second radiating arm of the ultra high frequency antenna.
1. An RFID device, comprising:
a conductive sheet defining first and second portions, with an intermediate portion joining the first and second portions;
a dual-input RFID chip configured to receive high frequency inputs and ultra high frequency inputs;
a first connection electrically coupling the first portion of the conductive sheet and the RFID chip;
a second connection electrically coupling the second portion of the conductive sheet and the RFID chip; and
a third connection electrically coupling the intermediate portion of the conductive sheet and the RFID chip, such that at least one of the connections comprises a conductive connection via a conductive adhesive, wherein
the first portion of the conductive sheet defines a multi-turn high frequency antenna having one or more disruptions in the conductive sheet positioned between and/or defining adjacent turns of the multi-turn high frequency antenna,
the second portion of the conductive sheet defines a first radiating arm of an ultra high frequency antenna, and
the one or more disruptions in the first portion of the conductive sheet comprise one or more openings in the conductive sheet and are configured to reduce the conductivity of the conductive sheet at the location of the one or more disruptions to a low enough level so as to direct a high frequency current around the turns of the multi-turn high frequency antenna rather than across the one or more disruptions, while allowing an ultra high frequency current to flow across the one or more disruptions, thereby resulting in the first portion of the conductive sheet defining a second radiating arm of the ultra high frequency antenna and at least a section of the one or more disruptions in the first portion of the conductive sheet defines a generally sinusoidal local pattern in a plane defined by the conductive sheet.
2. The RFID device of claim 1 , wherein said one or more disruptions in the first portion of the conductive sheet comprise one or more thinned areas of the conductive sheet.
3. The RFID device of claim 1 , wherein said one or more disruptions in the first portion of the conductive sheet comprise one or more additive materials applied to the conductive sheet to decrease the conductivity of the conductive sheet at the location or locations of said one or more disruptions.
4. The RFID device of claim 1 , wherein at least one of the connections comprises a weld.
5. The RFID device of claim 1 , wherein at least one of the connections comprises a capacitive connection with a non-conductive adhesive.
6. An RFID device, comprising:
a conductive sheet defining first and second portions, with an intermediate portion joining the first and second portions;
a high frequency-input RFID chip;
an ultra high frequency-input RFID chip;
a first connection electrically coupling the first portion of the conductive sheet and the high frequency RFID chip;
a second connection electrically coupling the second portion of the conductive sheet and the ultra high frequency-input RFID chip; and
a third connection electrically coupling the intermediate portion of the conductive sheet and the RFID chips, wherein
the first portion of the conductive sheet defines a multi-turn high frequency antenna having one or more disruptions in the conductive sheet positioned between and/or defining adjacent turns of the multi-turn high frequency antenna, said one or more disruptions in the first portion of the conductive sheet comprise one or more thinned areas of the conductive sheet,
the second portion of the conductive sheet defines a first radiating arm of an ultra high frequency antenna, and
the one or more disruptions in the first portion of the conductive sheet are configured to reduce the conductivity of the conductive sheet at the location of the one or more disruptions to a low enough level so as to direct a high frequency current around the turns of the multi-turn high frequency antenna rather than across the one or more disruptions, while allowing an ultra high frequency current to flow across the one or more disruptions, thereby resulting in the first portion of the conductive sheet defining a second radiating arm of the ultra high frequency antenna.
7. The RFID device of claim 6 , wherein said one or more disruptions in the first portion of the conductive sheet comprise one or more openings in the conductive sheet.
8. The RFID device of claim 7 , wherein at least a section of said one or more disruptions in the first portion of the conductive sheet defines a generally sinusoidal local pattern in a plane defined by the conductive sheet.
9. The RFID device of claim 6 , wherein at least a section of said one or more disruptions in the first portion of the conductive sheet defines a generally sinusoidal local pattern in a plane defined by the conductive sheet.
10. The RFID device of claim 6 , wherein said one or more disruptions in the first portion of the conductive sheet comprise one or more additive materials applied to the conductive sheet to decrease the conductivity of the conductive sheet at the location or locations of said one or more disruptions.
11. The RFID device of claim 10 , wherein at least a section of said one or more disruptions in the first portion of the conductive sheet defines a generally sinusoidal local pattern in a plane defined by the conductive sheet.
12. The RFID device of claim 6 , wherein at least one of the connections comprises a conductive connection via a conductive adhesive.
13. The RFID device of claim 6 , wherein at least one of the connections comprises a weld.
14. The RFID device of claim 6 , wherein at least one of the connections comprises a capacitive connection with a non-conductive adhesive.