RF antenna system having low-power requirements for RFID tag communication

• US 8,120,540 B1
• Filed: 06/06/2008
• Issued: 02/21/2012
• Est. Priority Date: 06/06/2008
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Armstrong, Lincoln
• Primary Examiner(s): Dinh, Trinh
• Application Number:
  US12/214,301
• Time in Patent Office: 1,355 Days
• Field of Search: None
• US Class Current: 343/718
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 9/44 with a plurality of divergent straight elements, e.g. V-dipole, X-antenna; with a plurality of elements having mutually inclined substantially straight portions combinations of two or more active elements H01Q21/00; turnstile antennas H01Q21/26

Abstract

An RF antenna system for RFID tag communication includes a terminal and wire antennas extending therefrom. Each wire antenna has a first end electrically coupled to the terminal and a second end that is unencumbered. At least a portion of each wire antenna to include the second end thereof is flexible in at least one direction so that an RFID tag of an RFID-tagged object contacts at least one of the wire antennas.

Claims

1. An RF antenna system for communication with an RFID tag, comprising:

a terminal electrically coupled to an RF source and an RFID reader, said source electromagnetic excitation energy to the RFID tag, said reader able to receive an excitation signal from the RFID tag; and

a plurality of wire antennas extending from said terminal, each of said plurality of wire antennas having a first end and a second end with said first end electrically coupled to said terminal and each said second end is unencumbered,

wherein at least a portion of said plurality of wire antennas include said second ends thereof is flexible in at least one direction.

2. The RF antenna system as in claim 1, wherein said portion of each of said plurality of wire antennas is circular in cross-section.

3. The RF antenna system as in claim 1, wherein said portion of each of said plurality of wire antennas is non-circular in cross-section.

4. The RF antenna system as in claim 1, where said portion of each, of said plurality of wire antennas is oblong in cross-section.

5. The RF antenna system as in claim 1, wherein said plurality of wire antennas are arranged vertically with said second ends thereof are disposed below said first ends thereof.

6. The RF antenna system as in claim 1,, wherein said plurality of wire antennas are arranged horizontally.

7. The RF antenna system as in claim 1, further comprising electrical insulation being disposed about each of said plurality of wire antennas.

8. The RF antenna system as in claim 1, wherein each of said plurality of wire antennas comprises a single strand of wire conductor.

9. The RF antenna system as in claim 1, wherein each of said plurality of wire antennas comprises multiple strands of wire conductors.

10. The RF antenna system as in claim 1, wherein said second ends of said plurality of wire antennas are arrayed substantially along a line.

11. The RF antenna system as in claim 1, wherein said second ends of said plurality of wire antennas are arrayed in a two-dimensional arrangement.

12. The RF antenna system as in claim 11, wherein said two-dimensional arrangement is random.

13. The RF antenna system as in claim 11, wherein said two-dimensional arrangement is ordered.

14. The RF antenna system as in claim 1, wherein said cross-section is oblong.

15. An RF antenna system for communication with an RFID tag, comprising:

a terminal electrically coupled to an RF source and an RFID reader, said source emitting electromagnetic excitation energy to the RFID tag, said reader able to receive an excitation signal from the RFID tag; and

a plurality of wire antennas, each of said plurality of wire antennas are electrically and mechanically coupled on just one end thereof to said terminal and extends away therefrom in a substantially straight-line fashion to an open-circuit termination that is mechanically free,

wherein said plurality of wire antennas define a curtained arrangement, and

wherein at least a portion of each of said plurality of wire antennas includes a cross-section that defines flexibility in at least one preferred direction.

16. The RF antenna system as in claim 15, wherein said cross-section defines flexibility in opposing directions.

17. The RF antenna system as in claim 15, wherein said cross-section is non-circular.

18. The RF antenna system as in claim 15, wherein said plurality of wire antennas extend vertically downward from said terminal.

19. The RF antenna system as in claim 15, wherein said plurality of wire antennas extend horizontally from said terminal.

20. The RF antenna system as in claim 15, further comprising electrical insulation disposed about each of said plurality of wire antennas.

21. The RF antenna system as in claim 15, wherein each of said plurality of wire antennas comprises a single strand of wire conductor.

22. The RF antenna system as in claim 15, wherein each of said plurality of wire antennas comprises multiple strands of wire conductors.

23. The RF antenna system as in claim 15, wherein said curtained arrangement of said plurality of wire antennas lie substantially in a plane.

24. The RF antenna system as in claim 15, wherein said curtained arrangement of said plurality of wire antennas comprises a random three-dimensional arrangement of said plurality of wire antennas.

25. The RF antenna system as in claim 15, wherein said curtained arrangement of said plurality of wire antennas comprises an ordered three-dimensional arrangement of said wire antennas.

26. The RF antenna system as in claim 15, wherein an object carrying the RFID tag substantially contacts at least one of said plurality of wire antennas.

27. An RFID interrogation system for communication with an RFID tag, comprising:

an RF source emitting electromagnetic excitation energy to the RFID tag;

an RFID reader able to receive an excitation signal from the RFID tag;

a terminal electrically coupled to said RF source and said RFID reader; and

a plurality of wire antennas extending from said terminal, each of said plurality of wire antennas having a first end and a second end with said first end electrically coupled to said terminal, and each said second end being unencumbered,

wherein at least a portion of said plurality of wire antennas include said second ends thereof is flexible in at least one direction.

28. The RFID interrogation system as in claim 27, wherein said second ends of said plurality of wire antennas arc arrayed in a two-dimensional arrangement.