REMOTELY POWERED TRANSPONDER

• US 3,745,569 A
• Filed: 07/22/1971
• Issued: 07/10/1973
• Est. Priority Date: 07/22/1971
• Status: Expired due to Term

• Current Assignee: Edward D. Ostroff, John C. Murray, Nathan Freedman, Works George A
• Original Assignee: Edward D. Ostroff, John C. Murray, Nathan Freedman, Works George A
• Inventors: Works, George A., Murray, John C., Freedman, Nathan, Ostroff, Edward D.
• Primary Examiner(s): Bentley, Stephen C.
• Application Number:
  US05/165,219
• Time in Patent Office: 719 Days
• Field of Search: 343/6.5R,6.5LL,6.5SS,6.8R,6.8LC
• US Class Current: 342/44
• CPC Class Codes: B07C 3/12 using electric or electronic detecting means B07C3/14 takes precedence
• CPC Class Codes: B61L 25/045 using reradiating tags
• CPC Class Codes: B65G 47/49 without bodily contact between article or load carrier and automatic control device , e.g. the destination marks being electrically or electronically detected
• CPC Class Codes: G01S 13/758 using a signal generator powered by the interrogation signal
• 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: H01Q 3/46 Active lenses or reflecting arrays

Abstract

A transponder having a circuit for the extraction of power from an incident interrogating beam of electromagnetic energy, the extracted power being utilized to operate a digital coding circuit. The transponder further comprises an oscillator circuit for developing a train of pulses of electromagnetic energy with successive pulses occurring in a coded format in accordance with a digital code imparted by the digital coding circuit. The transponder is of sufficiently small size to be affixed in the form of a tag to automobiles, personnel, containers and other objects to be identified. The electronic tag communicates with an interrogation system.

Claims

1. In combination:

means for extracting power from an incident radiant signal comprising a succession of pulses; and

means energized by said extracted power for generating a train of pulses coded in a digital format, said coded pulse generating means comprising means for gating pulses of said train of pulses in synchronism with the individual pulses of said succession of pulses of said radiant signal.

2. The combination according to claim 1 further comprising means responsive to said coded pulse train for displaying information provided by said coded pulse train.

3. The combination according to claim 1 further comprising:

a source of said radiant signal, said radiant signal comprising a succession of pulses of radiant energy;

means for receiving said coded pulse train; and

means synchronized to transmissions of said radiant energy pulses for correlating at least a portion of said coded pulse train with a reference code.

4. In combination:

means responsive to an incident radiant signal for extracting power from said radiant signal;

means energized by said extracted power for generating a train of pulses coded in a digital format, said power extracting means comprising;

a plurality of antenna elements;

a plurality of serially connected diodes, each of said diodes being coupled to respective ones of said antenna elements; and

means for storing power extracted by said diodes from a signal incident upon said antenna elements.

5. The combination according to claim 1 wherein said generating means includes means for varying said code.

6. The combination according to claim 1 wherein said radiant signal comprises a train of first pulses, and said coded signal comprises a train of second pulses, the occurrences of predetermined ones of said second pulses being deleted from said train of second pulses in accordance with said code.

7. In combination:

a radiating element;

diode means coupled to said radiating element for extracting power from radiation incident upon said radiating element;

counting means energized from said power for counting successive pulsations in said power;

an oscillator circuit for providing a radiant energy signal; and

logic means responsive to the count of said counter for activating said oscillator circuit.

8. The combination according to claim 7 wherein said logic means comprises a matrix conductor array having preselected cross points coupled during one condition of relative polarities of conductors at a cross point and decoupled during an alternate condition of relative polarities of conductors at said cross point, said conductors being energized respectively by said counting means in accordance with the count of said counter.

9. The combination according to claim 8 wherein said oscillator circuit comprises:

an energy storage unit;

a reactive impedance element; and

a nonlinear active element cooperating with said reactive impedance element to provide a relaxation type oscillation, the energy for said relaxation oscillations being supplied by said energy storage unit, said relaxation oscillations being delayed in time from a charging of said energy storage unit until current drained via said nonlinear active element has reduced the voltage of said energy storage unit to a value suitable for initiating said relaxation oscillations.

10. The combination according to claim 9 wherein said counting means comprises a first counter and a second counter, said first counter and said second counter each having a decoder for decoding the counts of said first counter and said second counter, each of said decoders energizing respective groups of conductors of said matrix conductor array.

11. The combination according to claim 10 wherein said nonlinear active element is a tunnel diode.

12. The combination according to claim 11 wherein said oscillator circuit further comprises an antenna for transmitting said radiant energy signal of said oscillator circuit at a frequency different from the frequency of said radiation incident upon said radiating element.

13. A message communication system comprising:

means for generating an interrogating signal, said interro-gating signal comprising a succession of pulses;

means for applying a stored message to an object;

means energized solely by power from said interrogating signal for transmitting said stored message from said object, said transmitting means comprising means for gating said transmitted message in synchronism with individual pulses of said succession of pulses of said interrogating signal to provide gated portions of said transmitted message which correspond to respective ones of said pulses of said succession of pulses;

And means for receiving said transmitted message, sa1d receiving means including means synchronized with individual pulses of said succession of pulses of said interrogating signal for performing a correlation on said received message.

14. A message communication system comprising:

means for generating an interrogating signal, said interro-gating signal comprising a succession of pulses;

means for applying a stored message to an object;

means energized solely by power from said interrogating signal for transmitting said stored message from said object, said transmitting means comprising means for synchronizing successive portions of said transmitted message with said interrogating signal; and

means for receiving said transmitted message.

15. The system according to claim 14 wherein said message applying means includes a memory storage array in which bits of data are individually stored.

16. The system according to claim 15 wherein said bits of stored data may be individually varied.

17. The system according to claim 16 wherein said message applying means comprises means attached to said object for varying said bits of stored data.

18. The system according to claim 17 wherein said transmitting means comprises means for extracting energy from said interrogating signal and storing such energy, and means for reradiating a portion of such energy as a signal modulated with said bits of data to accomplish said transmission of said stored message.

19. A transponder for communicating a message comprising:

means responsive to a succession of pulses of incident radiant energy for providing a unidirectional voltage therefrom;

means for storing energy of a direct component of said unidirectional voltage;

means for reradiating a portion of said stored energy;

means for counting pulses of said succession of pulses of incident energy;

means for storing a message, said storing means including means responsive to the count of said counting means for extracting information from said stored message; and

means for modulating a signal of said reradiated energy with said information of said stored signal.

20. A transponder for communicating a message comprising:

means responsive to incident radiant energy for providing a unidirectional voltage therefrom;

means for storing energy of a different component of said unidirectional voltage;

means for reradiating a portion of said stored energy;

means for storing a message;

means for modulating a signal of said reradiated energy with information of said stored signal, and wherein said unidirectional voltage means comprises;

an array of radiators for intercepting said incident radiation and providing an electric field therefrom;

means for providing a ground plane, said radiators being spaced apart from each other and being uniformly spaced from said ground plane;

conducting elements serially interconnecting pairs of said radiators, said conducting elements extending from said radiators towards said ground plane, a first part of individual ones of said conducting elements being parallel to said ground plane to provide predetermined values of capacitance for filtering energy of said electric field; and

rectifier means coupled between pairs of said radiators and responsive to said electric field for providing said unidirectional voltage.

21. The transponder according to claim 20 wherein a second part of individual ones of said conducting elements of said unidirectional voltage means are configured for providing inductances, said capacitances and said inductances serving as a filter for extracting said direct component of said unidirectional voltage.

22. The transponder according to claim 21 wherein said message storage means comprises a first and a second set of conductor elements of which a preselected conductor element of said first set communicates with a plurality of preselected conductor elements of said second set.

23. The tRansponder according to claim 23 further comprising switching means interconnecting with said message storage means for altering said communications between conductor elements of said first and said second sets of conductor elements.

24. A transponder for communicating a message comprising:

means responsive to incident radiant energy for providing a unidirectional voltage therefrom, said unidirectional voltage means comprising an array of radiators for intercepting said incident radiation and providing an electric field therefrom, and rectifier means responsive to said electric field for providing said unidirectional voltage;

means for storing energy of a direct component of said unidirectional voltage, said energy storage means including a filter for extracting said direct component of said unidirectional voltage;

means for reradiating a portion of said stored energy;

means for storing a message, said message storage means comprising a first and a second set of conductor elements in which a preselected conductor element of said first set communicates with a plurality of preselected conductor elements of said second set, said message storage means further comprising means coupled to said first set of conductor elements for counting successive quanta of said incident radiant energy;

means coupled to said reradiating means for modulating a signal of said reradiated energy with information of said stored message; and

switching means interconnecting with said message storage means for altering said communications between conductor elements of said first and said second set of conductor elements.

25. The transponder according to claim 24 wherein said modulating means is responsive to currents communicated between a pair of said conductor elements of which one element of said pair is of said first set and the other element of said pair is of said second set of conductor elements, different pairs of said conductor elements being activated in accordance with the count of said counting means.

26. The transponder according to claim 25 wherein said modulating means modulates said signal of reradiated energy with the portion of the information of said stored signal corresponding to the pair of conductor elements activated by said counting means at each count of said counting means.

27. The transponder according to claim 26 wherein said modulation of said signal of said reradiated energy is a pulse code modulation.