Wide band RFID system with tag on flexible label
First Claim
1. An active radio frequency identification (RFID) tag implemented as a flat label, the tag comprising:
- (a) a battery printed on the label;
(b) a flat antenna printed on the label; and
(c) a communications circuit as an inlay on the label, wherein said circuit is operatively attached to said battery and to said antenna said communications circuit including transmitter and receiver circuitry; and
(d) an inaccurate clock source operatively attached to said communications circuit;
wherein said communications circuit performs timing measurements on incoming received waveforms and transmits transmit signals in response to said received waveforms with timing based on said timing measurements.
13 Assignments
0 Petitions
Accused Products
Abstract
An active radio frequency identification (REID) tag implemented on a flat label. The tag includes a battery printed on the label, a flat wide-band antenna printed on the label and a wide band communication circuit implemented as a chip inlay inside the label. The circuit is attached to the battery and to the antenna. The combined thickness of the battery, the antenna and the circuit as printed on the flexible label is less than one millimeter. The battery, the antenna and the circuit are printed on the label so as to render substantial flexibility to the RFID tag. The circuit operates at a center frequency of at least one gigahertz and a bandwidth at least twenty percent of said center frequency or a bandwidth at least 500 Mhz. The tag typically includes an inaccurate clock source such as an RC circuit and does not include a crystal. Average power consumption of the battery is preferably reduced by operating the tag with a low duty ratio between an active and an inactive interval; and during the active interval transmitting in bursts while turning off parts of the tag between the bursts. The communications circuit performs timing measurements on incoming received waveforms and transmits transmit signals in response to the received waveforms with timing based on the timing measurements. The receiver circuitry locks on a repetition frequency of the incoming received waveforms, and based on the repetition frequency generates a pulse repetition frequency of the transmit signals.
53 Citations
25 Claims
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1. An active radio frequency identification (RFID) tag implemented as a flat label, the tag comprising:
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(a) a battery printed on the label; (b) a flat antenna printed on the label; and (c) a communications circuit as an inlay on the label, wherein said circuit is operatively attached to said battery and to said antenna said communications circuit including transmitter and receiver circuitry; and (d) an inaccurate clock source operatively attached to said communications circuit; wherein said communications circuit performs timing measurements on incoming received waveforms and transmits transmit signals in response to said received waveforms with timing based on said timing measurements. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of communicating in a communication system, the system including a reader and a label tag whose components are inlayed on the label tag, wherein the label tag includes an inaccurate clock source, the method comprising the steps of:
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(a) transmitting by the label tag a transmission based on the inaccurate clock source; (b) receiving by the reader said transmission; and (c) the reader upon synchronizing on a center frequency and a pulse repetition frequency of said transmission, attempting to demodulate data included in said transmission. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A communications system comprising:
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(a) a label tag including a battery printed on said label tag, a flat antenna printed on said label tag, and a communications circuit as an inlay on said label tag, wherein said circuit is operatively attached to said battery and to said antenna; (b) a reader in communication with said label tag, wherein said reader, upon synchronizing on a center frequency and a pulse repetition frequency of a transmission from said label tag, attempts to demodulate data included in said transmission. - View Dependent Claims (23)
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24. An active radio frequency identification (RFID) tag implemented as a flat label, the tag comprising:
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(a) a battery printed on the label; (b) a flat antenna printed on the label; and (e) a communications circuit as an inlay on the label, wherein said circuit is operatively attached to said battery and to said antenna; wherein said circuit includes an ultra wide band transceiver circuit said transceiver circuit including an inaccurate frequency reference, such that said transceiver circuit estimates a received center frequency of a received waveform and based on said received center frequency said transceiver circuit transmits an ultra wide band pulsed waveform with a locked transmit center frequency based on said received center frequency.
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25. An active radio frequency identification (RFID) tag implemented as a flat label, the tag comprising:
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(a) a battery printed on the label; (b) a flat antenna printed on the label; and (c) a communications circuit as an inlay on the label, wherein said circuit is operatively attached to said battery and to said antenna; wherein said circuit includes a transceiver circuit said transceiver circuit including an inaccurate frequency reference, such that said transceiver circuit estimates a received center frequency of a received waveform and said transceiver circuit locks a timing of a transmitted signal based on said received center frequency.
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Specification