SAW identification tag discrimination methods

• US 20050056695A1
• Filed: 09/15/2004
• Published: 03/17/2005
• Est. Priority Date: 09/15/2003
• Status: Active Grant

• Current Assignee: RF Saw Components Incorporated
• Original Assignee: RF Saw Components Incorporated
• Inventors: Hartmann, Clinton S., Bellamy, John C.
• Granted Patent: US 7,264,149 B2
• Time in Patent Office: Days
• US Class Current: 235/380
• CPC Class Codes: G06K 19/0672 with resonating marks
• 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: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves

Abstract

Surface acoustic wave (SAW) identification tag discrimination methods including, in one embodiment (1) detecting a signal emanating from an electronic device operating within a SAW tag frequency band; (2) identifying a null period in a transmission pattern in the signal; and (3) effecting communication of information during the null period.

Claims

1. A method of communicating surface acoustic wave (SAW) identification tag information, comprising:

detecting a signal emanating from an electronic device operating within a SAW tag frequency band;

identifying a null period in a transmission pattern in said signal; and

effecting communication of said information during said null period.

2. The method as recited in claim 1 wherein said null period is a frequency null period.

3. The method as recited in claim 1 wherein said null period is a time null period.

5. The method as recited in claim 1 further comprising utilizing frequency shift to determine the timing of said short bursts.

4. A method of communicating surface acoustic wave (SAW) identification tag information to avoid signal interference with another device operating within the same frequency band, comprising:

effecting communication of said information using low power;

causing said effecting communication to occur in signal bursts.

6. A method of communicating SAW identification tag information, comprising:

detecting at least one other signal emanating from an electronic device operating within a SAW tag frequency band; and

effecting communication of said information synchronous with said at least one other signal such that said communication occurs during an interval when said at lest one other signal is inactive.

7. The method as recited in claim 6 wherein said effecting communication is synchronous in time.

8. The method as recited in claim 6 wherein said effecting communication in synchronous in frequency.

9. A SAW identification tag, comprising:

at least two tag identification number reflector groups located on a substrate;

a first error-checking reflector group located on said substrate and dependent upon data contained in one of said at least two tag identification number reflector groups;

a second error-checking reflector group located on said substrate and dependent upon data contained in at least a remaining one of said at least two tag identification number reflector groups; and

a third error-checking reflector group located on said substrate and dependent upon data contained in said at least said remaining one tag identification number reflector group and said second error-checking reflector group.

10. A SAW identification tag, comprising:

at least one tag identification number reflector group located on a substrate;

at least one synchronizing reflector group located on said substrate.

11. The SAW identification tag as described claim 10 wherein said synchronizing reflector group is a mirror image of said at least one tag identification number reflector group.

12. A SAW identification tag, comprising:

at least one tag identification number reflector group located on a substrate;

a first error-checking reflector group located on said substrate and dependent upon data contained in said at least one tag identification number reflector group; and

a second error-checking reflector group located on said substrate and dependent upon data contained in said at least one tag identification number reflector group and said first error-checking reflector group.

13. A SAW identification tag, comprising:

at least one tag identification number reflector group located on a substrate;

at least one error-checking reflector group located on said substrate and dependent upon data contained in said at least one tag identification number reflector group.

14. A SAW identification tag, comprising:

a first group of reflectors located on a substrate and having substantially similar first reflection characteristics; and

a second group of reflectors located on said substrate.

15. The SAW identification tag as recited in claim 14 further comprising:

said second group of reflectors having substantially similar second reflection characteristics; and

said first reflection characteristics and said second reflection characteristics are substantially similar.

16. A SAW identification tag, comprising:

a group of reflectors located on a substrate; and

each of said reflectors having substantially similar reflection characteristics.

17. A SAW identification tag, comprising:

a substrate having a group of reflectors located thereon; and

a start reflector located to generate a reflected response to a SAW tag interrogation signal before a reflector in said group of reflectors generates a reflected response to said interrogation signal.

18. The SAW identification tag as recited in claim 17 wherein said start reflector is located a predetermined distance from said group of reflectors.

19. A SAW identification tag, comprising:

a substrate having a group of reflectors located thereon; and

an end-of-tag reflector located to generate a reflected response to a SAW tag interrogation signal after each reflector in said group of reflectors generates a reflected response to said interrogation signal.

20. The SAW identification tag as recited in claim 19 wherein said end-of-tag reflector is located a predetermined distance from the group of reflectors wherein a reflector last generating a reflected response to an interrogation signal.

21. The SAW identification tag as recited in claim 19 wherein said end-of-tag reflector reflects substantially all of said interrogation signal.

22. The SAW identification tag as recited in claim 19 wherein said end-of-tag reflector generates a reflected interrogation signal that generates response pulses from said reflectors.