Surface acoustic wave identification tag having enhanced data content and methods of operation and manufacture thereof

• US 7,407,111 B2
• Filed: 07/15/2005
• Issued: 08/05/2008
• Est. Priority Date: 12/18/2001
• Status: Expired due to Fees

• Current Assignee: RF Saw Components Incorporated
• Original Assignee: RF Saw Components Incorporated
• Inventors: Hartmann, Clinton S.
• Primary Examiner(s): Kim, Ahshik
• Application Number:
  US11/182,385
• Publication Number:
  US 20050264423A1
• Time in Patent Office: 1,117 Days
• Field of Search: 235/375, 235/492, 235/451
• US Class Current: 235/492
• CPC Class Codes: G01S 13/755 using delay lines, e.g. acoustic delay lines
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00
• CPC Class Codes: G06K 19/0675 the resonating marks being of the surface acoustic wave [SAW] kind SAW devices per se H03H9/64
• CPC Class Codes: H03H 9/6406 Filters characterised by a particular frequency characteristic

Abstract

A surface acoustic wave (SAW) identification tag and methods of operating and manufacturing the tag. In one embodiment, the tag includes: (1) a piezoelectric substrate having a SAW transducer located thereon, (2) a group of slots arranged by both pulse position and phase position on said substrate; and (3) a number of reflectors distributed among the slots such that the reflectors encode a number by both pulse position and phase position.

Claims

1. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.

2. The SAW identification tag as recited in claim 1 wherein said phase is in quadrature.

3. The SAW identification tag as recited in claim 1 further comprising a framing reflector located between said SAW transducer and said group of reflector locations.

4. The SAW identification tag as recited in claim 1 further comprising a plurality of said group of reflector locations separated by dead spaces.

5. The SAW identification tag as recited in claim 4 wherein said plurality is at least four and said number is at least 32 bits long.

6. The SAW identification tag as recited in claim 1 wherein said number is at least 8 bits long.

7. The identification tag as recited in claim 1 wherein at least one of said reflectors is a single strip of conductive material.

8. The identification tag as recited in claim 1 wherein said number is unique to said tag.

9. The identification tag as recited in claim 1 wherein said number contains data pertaining to an object associated with said tag.

10. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase wherein said number includes an error detection portion.

11. A method of operating a surface acoustic wave (SAW) identification tag, comprising:

exciting a SAW transducer located on a piezoelectric substrate to create a SAW;

causing said SAW to reflect from reflectors distributed among a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase; and

demodulating reflected portions of said SAW to yield a number encoded simultaneously by both said pulse position and said phase.

12. The method as recited in claim 11 wherein said reflectors are arranged wherein said phase is in quadrature.

13. The method as recited in claim 11 further comprising causing said SAW to reflect from a framing reflector located between said SAW transducer and said group of reflector locations.

14. The method as recited in claim 11 further comprising causing said SAW to reflect from reflectors distributed among a plurality of said group of reflector locations separated by dead spaces.

15. The method as recited in claim 14 wherein said plurality is at least four and said number is at least 32 bits long.

16. The method as recited in claim 11 wherein said number is at least 8 bits long.

17. The method as recited in claim 11 wherein at least one of said reflectors is a single strip of conductive material.

18. The method as recited in claim 11 wherein said number is unique to said tag.

19. The method as recited in claim 11 wherein said number contains data pertaining to an object associated with said tag.

20. A method of operating a surface acoustic wave (SAW) identification tag, comprising:

exciting a SAW transducer located on a piezoelectric substrate to create a SAW;

causing said SAW to reflect from reflectors distributed among a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase; and

demodulating reflected portions of said SAW to yield a number encoded simultaneously by both said pulse position and said phase wherein said number includes an error detection portion.

21. A method of manufacturing a surface acoustic wave (SAW) identification tag, comprising:

forming a SAW transducer on a piezoelectric substrate; and

depositing reflectors among reflector locations arranged in a group on said substrate, each of said reflector locations having both a pulse position and a phase, said reflectors simultaneously encoding a number by both pulse position and phase.

22. The method as recited in claim 21 wherein said reflectors are arranged wherein said phase is in quadrature.

23. The method as recited in claim 21 further comprising depositing a framing reflector between said SAW transducer and said group.

24. The method as recited in claim 21 further comprising a plurality of said groups separated by dead spaces.

25. The method as recited in claim 24 wherein said plurality of groups is at least four and said number is at least 32 bits long.

26. The method as recited in claim 21 wherein said number is at least 8 bits long.

27. The method as recited in claim 21 wherein at least one of said reflectors is a single strip of conductive material.

28. The method as recited in claim 21 wherein said number is unique to said tag.

29. The method as recited in claim 21 wherein said number contains data pertaining to an object associated with said tag.

30. A method of manufacturing a surface acoustic wave (SAW) identification tag, comprising:

forming a SAW transducer on a piezoelectric substrate; and

depositing reflectors among reflector locations arranged in a group on said substrate, each of said reflector locations having both a pulse position and a phase, said reflectors simultaneously encoding a number by both pulse position and phase wherein said number includes an error detection portion.

31. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase wherein said phase is defined relative to neighboring reflector locations; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.

32. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase wherein non-uniform spacing is utilized for said pulse position; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.

33. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase wherein non-uniform spacing is utilized for said phase; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.

34. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase wherein non-uniform spacing is utilized for both said pulse position and said phase; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.

35. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase wherein a minimum reflector spacing rule is followed when determining the placement of said reflectors distributed among said reflector locations.

36. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon wherein said SAW transducer has a unidirectional character;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.

37. A surface acoustic wave (SAW) identification tag, comprising:

a piezoelectric substrate having a SAW transducer located thereon;

a group of reflector locations on said substrate, each of said reflector locations arranged by both a pulse position and a phase wherein said phase of reflector locations is implemented using fine grain spatial adjustment of reflector elements by a fraction of a SAW wavelength on the device surface; and

a number of reflectors distributed among said reflector locations such that said reflectors encode a number simultaneously by both said pulse position and said phase.