Security tag with three dimensional antenna array made from flat stock

• US 20050040994A1
• Filed: 08/09/2004
• Published: 02/24/2005
• Est. Priority Date: 08/22/2003
• Status: Active Grant

• Current Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Original Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Inventors: Piccoli, Anthony F., Clare, Thomas J., Eckstein, Eric, Mazoki, Gary T.
• Granted Patent: US 7,042,413 B2
• Time in Patent Office: Days
• US Class Current: 343/809
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A three-dimensional dipole antenna system for an RFID tag that optimizes detection for a given available volume in which to situate the RFID tag.

Claims

1. An antenna configuration for use in a security tag that optimizes the receipt of a signal issued from an interrogator or reader, said antenna configuration comprising:

a first dipole and a second dipole arranged in a non-parallel nor collinear configuration to form a plane comprising said first and second dipoles; and

a third dipole being positioned out of said plane.

2. The antenna configuration of claim 1 wherein said first, second and third dipoles are tuned to RF frequencies.

3. The antenna configuration of claim 2 wherein said RF frequencies are UHF frequencies in the frequency band of approximately 850 MHz-950 MHz.

4. The antenna configuration of claim 2 wherein said RF frequencies are microwave frequencies in the frequency band of approximately 2.3 Ghz-2.6 GHz.

5. The antenna configuration of claim 1 wherein said third dipole comprises a first antenna stub and a second antenna stub and wherein said plane comprises a first side and a second side and wherein said first and second side are opposite each other, said first antenna stub being positioned out of said plane on said first side and said second antenna stub being positioned out of said plane on said second side.

6. The antenna configuration of claim 5 wherein said first antenna stub and said second antenna stub are positioned orthogonally to said first and second sides, respectively.

7. The antenna configuration of claim 6 wherein said first, second and third dipoles are tuned to RF frequencies.

8. The antenna configuration of claim 7 wherein said RF frequencies are UHF frequencies in the frequency band of approximately 850 MHz-950 MHz.

9. The antenna configuration of claim 7 wherein said RF frequencies are microwave frequencies in the frequency band of approximately 2.3 Ghz-2.6 GHz.

10. The antenna configuration claim 1 wherein said first, second and third dipoles are formed as part of a web material and wherein said plane comprises said web material, said first and second dipoles being part of said web material and wherein said third dipole projects away from said web material.

11. The antenna configuration of claim 10 wherein said third dipole comprises a first antenna stub and a second antenna stub and wherein said web material comprises a first side and a second side and wherein said first and second side are opposite each other, said first antenna stub being positioned out of said web material on said first side and said second antenna stub being positioned out of said web material on said second side.

12. The antenna configuration of claim 11 wherein said first antenna stub and said second antenna stub are positioned orthogonally to said first and second sides, respectively.

13. The antenna configuration of claim 11 wherein said first, second and third dipoles are tuned to RF frequencies.

14. The antenna configuration of claim 13 wherein said RF frequencies are UHF frequencies in the frequency band of approximately 850 MHz-950 MHz.

15. The antenna configuration of claim 13 wherein said RF frequencies are microwave frequencies in the frequency band of approximately 2.3 Ghz-2.6 GHz.

16. The antenna configuration of claim 12 wherein said first, second and third dipoles are tuned to RF frequencies.

17. The antenna configuration of claim 16 wherein said RF frequencies are UHF frequencies in the frequency band of approximately 850 MHz-950 MHz.

18. The antenna configuration of claim 16 wherein said RF frequencies are microwave frequencies in the frequency band of approximately 2.3 Ghz-2.6 GHz.

19. A method of fabricating a three-dimensional antenna for a security tag for optimizing the receipt of a signal issued from an interrogator or reader, said method comprising the steps of:

(a) providing a web material;

(b) forming a first dipole and a second dipole on said web material, said first dipole and said second dipole formed to be non-parallel nor collinear with respect to each other;

(c) forming a third dipole on said web material;

(d) cutting said web material to free a portion of said third dipole from said web material; and

(e) displacing said free portion out of said web material.

20. The method of claim 19 wherein said step of forming said third dipole on said web material comprises creating a first antenna stub and a second antenna stub and wherein said step of cutting said material comprises cutting said web material to free a first portion of said first antenna stub and to free a second portion of said second antenna stub.

21. The method of claim 20 wherein said web material has a first side and a second side, said first and second sides being opposite each other, and wherein step of displacing said free portion out of said web material comprises displacing said first and second portions away from said first side or away from said second side.

22. The method of claim 20 wherein said web material has a first side and a second side, said first and second sides being opposite each other, and wherein step of displacing said free portion out of said web material comprises displacing said first portion away from said first side and said second portion away from said second side.

23. The method of claim 21 wherein said step of displacing said first and second portions away from said first side or away from said second side comprises displacing said first and second portions orthogonally away from said first side or from said second side.

24. The method of claim 22 wherein said step of displacing said first portion away from said first side and said second portion away from said second side comprises displacing said first and second portions orthogonally away from said first and second sides respectively.