RF tagging system including RF tags with variable frequency resonant circuits
First Claim
1. An RF tagging system comprising:
- an RF tag including resonant circuit means being resonant at any one of a plurality of different frequencies within a frequency range, receiver means for receiving an interrogation signal, and control means responsive to receipt of said an interrogation signal by said receiver means for causing said resonant circuit means to be resonant at selected ones of said different frequencies in a predetermined time sequence corresponding to a predetermined identification code; and
an external reader including detecting means for detecting said selected resonant frequencies of said RF tag, and decoding means for decoding the time sequence of said selected resonant frequencies for recovering said predetermined identification code.
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Accused Products
Abstract
An RF tagging system which provides a large number of potential identification codes without increasing the physical size of RF tags used therein includes a plurality of RF tags (20, 90, 140, 230, 250) and an external reader (200). Each RF tag includes at least one resonant circuit (22, 92, 142, 231, 251) which is resonant at any one of a plurality of different frequencies, a receiver (34, 102, 152,244, 264) for receiving an interrogation signal, and a control (36,104,154,246, 266) responsive to receipt of an interrogation signal for causing its at least one resonant circuit to be resonant at selected ones of the different frequencies in a predetermined time sequence corresponding to a predetermined identification code. The external reader includes a detector (216, 218, 220, 222) for detecting the selected resonant frequencies of the RF tags and a decoder (226) for decoding the time sequence of the selected resonant frequencies for recovering the predetermined identification code.
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Citations
39 Claims
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1. An RF tagging system comprising:
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an RF tag including resonant circuit means being resonant at any one of a plurality of different frequencies within a frequency range, receiver means for receiving an interrogation signal, and control means responsive to receipt of said an interrogation signal by said receiver means for causing said resonant circuit means to be resonant at selected ones of said different frequencies in a predetermined time sequence corresponding to a predetermined identification code; and an external reader including detecting means for detecting said selected resonant frequencies of said RF tag, and decoding means for decoding the time sequence of said selected resonant frequencies for recovering said predetermined identification code. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An RF tag comprising:
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resonant circuit means for being resonant at any one of a plurality of different frequencies within a frequency range; receiver means for receiving an interrogation signal; and control means responsive to receipt of an interrogation signal by said receiver means for causing said resonant circuit means to be resonant at selected ones of said different frequencies in a predetermined time sequence. - View Dependent Claims (18, 19, 20, 21, 22)
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23. An RF tag comprising:
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a plurality of resonant circuits, each said resonant circuit being resonant within a respective different frequency range and at any one of a plurality of different frequencies within mid range; receiver means for receiving an interrogation signal; and control means responsive to receipt of said interrogation signal by said receiver means for causing each of said resonant circuits to be resonant at selected ones of said different frequencies in a predetermined time sequence. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. An RF tag comprising:
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a plurality of resonant circuits, each said resonant circuit being resonant at a different frequency; receiver means for receiving an interrogation signal; and control means responsive to receipt of said interrogation signal by said receiver means for causing said resonant circuits to be resonant at selected frequencies in a predetermined time sequence. - View Dependent Claims (37)
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38. An RF tagging system comprising:
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an RF tag including a plurality of resonant circuits, each said resonant circuit being resonant at a different frequency, receiver means for receiving an interrogation signal, and control means responsive to receipt of said interrogation signal by said receiver means for causing said resonant circuits to be resonant at selected frequencies in a predetermined time sequence corresponding to a predetermined identification code; and an external reader including detecting means for detecting said resonant frequencies of said resonant circuits, and decoding means for decoding the time sequence of said resonant frequencies for recovering said predetermined identification code. - View Dependent Claims (39)
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Specification