Radio frequency identification transponder
First Claim
Patent Images
1. A radio-frequency identification (“
- RFID”
) transponder the RFID transponder comprising;
a receiver for receiving a plurality of temporally spaced interrogating signals from an RFID interrogator, wherein each of the plurality of temporally spaced interrogating signal includes a respective identifier;
a memory array for storing first data, wherein the first data comprises a time stamp number of a first instance the RFID transponder was interrogated by the RFID interrogator and wherein the first data is indicative of an order of the temporally spaced interrogating signals;
a signal processor that extracts the respective identifier;
wherein the signal processor determines if the extracted identifier is different than the first data and if the RFID transponder was previously interrogated by the RFID interrogator;
responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was previously interrogated by the RFID interrogator, the first data remains unchanged; and
responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was not previously interrogated by the RFID interrogator, the first data is overwritten.
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Abstract
A radio frequency identification transponder including a power supply and a dynamic memory array which stores data. When power from the power supply ceases, the data in the dynamic memory array is validly maintained for a predetermined period of time. The dynamic memory array is responsive to an interrogating signal for selectively updating the data. A signal processor extracts an identifier from the interrogation signal and is responsive to the identifier and the stored data to determine whether some or all of the identifier is stored in the dynamic memory array.
100 Citations
30 Claims
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1. A radio-frequency identification (“
- RFID”
) transponder the RFID transponder comprising;a receiver for receiving a plurality of temporally spaced interrogating signals from an RFID interrogator, wherein each of the plurality of temporally spaced interrogating signal includes a respective identifier; a memory array for storing first data, wherein the first data comprises a time stamp number of a first instance the RFID transponder was interrogated by the RFID interrogator and wherein the first data is indicative of an order of the temporally spaced interrogating signals; a signal processor that extracts the respective identifier; wherein the signal processor determines if the extracted identifier is different than the first data and if the RFID transponder was previously interrogated by the RFID interrogator; responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was previously interrogated by the RFID interrogator, the first data remains unchanged; and responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was not previously interrogated by the RFID interrogator, the first data is overwritten. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 26, 27)
- RFID”
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21. A method of comparing signals transmitted between a radio-frequency identification (“
- RFID”
) interrogator and a RFID transponder with first data stored in a memory, the method comprising;transmitting, by the RFID interrogator, a plurality of temporally spaced interrogating signals, the temporally spaced interrogating signals including respective identifiers; receiving, by a receiver of the RFID transponder, the plurality of temporally spaced interrogating signals; extracting, by a signal processor of the RFID transponder, information from the received plurality of temporally spaced interrogating signals; determining, by the signal processor of the RFID transponder, if the extracted information is different than the first data and if the RFID transponder was previously interrogated by the RFID interrogator, wherein the first data is indicative of an order of the temporally spaced interrogating signals; responsive to a determination that the extracted information is different than the first data and that the RFID transponder was previously interrogated by the RFID interrogator, the first data remains unchanged; and responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was not previously interrogated by the RFID interrogator, the first data is overwritten. - View Dependent Claims (22, 23, 24, 25)
- RFID”
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28. A radio-frequency identification (“
- RFID”
) interrogator, the RFID interrogator comprising;a transmitter for transmitting a plurality of temporally spaced interrogating signals to at least one RFID transponder, the at least one RFID transponder comprising; a receiver for receiving the plurality of temporally spaced interrogating signals from the RFID interrogator, wherein each of the plurality of temporally spaced interrogating signal includes a respective identifier; a memory array for storing first data, wherein the first data comprises a time stamp number of a first instance the RFID transponder was interrogated by the RFID interrogator and wherein the first data is indicative of an order of the temporally spaced interrogating signals; a signal processor that extracts the respective identifier;
wherein the signal processor determines if the extracted identifier is different than the first data and if the RFID transponder was previously interrogated by the RFID interrogator; andresponsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was previously interrogated by the RFID interrogator, the first data remains unchanged; responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was not previously interrogated by the RFID interrogator, the first data is overwritten; a receiver for receiving a response signal from the at least one RFID transponder; a signal processor that extracts identity data from the response signal; wherein the response signal is compared with communications sent to each of the at least one RFID transponder; wherein the response signal includes the identity data derived from the temporally spaced interrogating signals; and wherein the identity data is indicative of an order of the temporally spaced interrogating signals. - View Dependent Claims (29)
- RFID”
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30. A radio frequency identification (RFID) system comprising:
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at least one RFID transponder for use with an RFID interrogator that provides a plurality of temporally spaced interrogating signals, the RFID transponder comprising; a first receiver for receiving the plurality of temporally spaced interrogating signals, wherein each of the plurality of temporally spaced interrogating signal includes a respective identifier; a memory array for storing first data, wherein the first data comprises a time stamp number of a first instance the RFID transponder was interrogated by the RFID interrogator and wherein the first data is indicative of an order of the temporally spaced interrogating signals; a first signal processor that extracts the respective identifier and determines if the extracted identifier is different than the first data and if the RFID transponder was previously interrogated by the RFID interrogator; and responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was previously interrogated by the RFID interrogator, the first data remains unchanged; responsive to a determination that the extracted identifier is different than the first data and that the RFID transponder was not previously interrogated by the RFID interrogator, the first data is overwritten; the RFID interrogator transmits to the at least one RFID transponder, the interrogating signals, the at least one RFID transponder providing, to the RFID interrogator, upon receipt of the identifier, a response signal, the RFID interrogator comprising; a second receiver for receiving the response signal from the at least one RFID transponder; a second signal processor that extracts identity data from the response signal; and wherein the response signal is compared with communications sent to each of the at least one RFID transponder.
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Specification