Radio frequency data communications device
First Claim
Patent Images
1. A radio frequency identification system comprising:
- a host computer including an application program to control an interrogator and to receive data from the interrogator;
a plurality of interrogators, including the interrogator coupled to the host computer and configured to transmit a forward link signal to implement an arbitration scheme to determine an identification code of an RFID tag from among a plurality of RFID tags contained within an RF field of the interrogator, the forward link signal comprising an RF carrier that is modulated using amplitude shift keying to provide a first parameter, a second parameter, a third parameter, a CRC, and return link configuration information;
an item of inventory having affixed thereto a label comprising identifying text; and
the RFID tag disposed on plastic substrate and laminated to a back side of the label to track the item via the host computer, the tag comprising a dipole antenna and no more than one monolithic integrated circuit storing an identification code associated with the item and configured to switch between a plurality of available modulation schemes, the tag configured to receive the signal via the dipole antenna, to store the first parameter, to compare the second parameter to a value stored in the integrated circuit other than the identification code, to generate a random number, to compare the third parameter to the first parameter, and to communicate a reply to the signal via the dipole antenna depending, at least in part, on whether the third parameter matches the first parameter and whether the second parameter matches the value, the reply comprising a return link signal modulated in accordance with a modulation scheme selected by the return link configuration information, wherein in accordance with one of the plurality of modulation schemes each bit of the return link signal is multiplied by a selectable one of at least three subcarrier sequences selected by the return link configuration information.
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Abstract
A radio frequency identification device includes an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.
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Citations
51 Claims
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1. A radio frequency identification system comprising:
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a host computer including an application program to control an interrogator and to receive data from the interrogator; a plurality of interrogators, including the interrogator coupled to the host computer and configured to transmit a forward link signal to implement an arbitration scheme to determine an identification code of an RFID tag from among a plurality of RFID tags contained within an RF field of the interrogator, the forward link signal comprising an RF carrier that is modulated using amplitude shift keying to provide a first parameter, a second parameter, a third parameter, a CRC, and return link configuration information; an item of inventory having affixed thereto a label comprising identifying text; and the RFID tag disposed on plastic substrate and laminated to a back side of the label to track the item via the host computer, the tag comprising a dipole antenna and no more than one monolithic integrated circuit storing an identification code associated with the item and configured to switch between a plurality of available modulation schemes, the tag configured to receive the signal via the dipole antenna, to store the first parameter, to compare the second parameter to a value stored in the integrated circuit other than the identification code, to generate a random number, to compare the third parameter to the first parameter, and to communicate a reply to the signal via the dipole antenna depending, at least in part, on whether the third parameter matches the first parameter and whether the second parameter matches the value, the reply comprising a return link signal modulated in accordance with a modulation scheme selected by the return link configuration information, wherein in accordance with one of the plurality of modulation schemes each bit of the return link signal is multiplied by a selectable one of at least three subcarrier sequences selected by the return link configuration information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for tracking items, comprising:
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an interrogator configured to transmit an interrogation signal to implement a collision arbitration scheme to determine a respective identification code of each respective RFID tag of plurality of RFID tags disposed within an RF field of the interrogator, the interrogation signal comprising a first parameter, a second parameter, a third parameter, and return link configuration information; an item to be tracked; and a label affixed to the item, the label comprising visual information on its front side and an RFID tag attached to its back side, the tag comprising an antenna disposed on a plastic sheet and an integrated circuit storing an identification code associated with the item, wherein the tag is configured to receive the interrogation signal via the antenna, to store the first parameter, to compare the second parameter to a value stored in the integrated circuit other than the identification code, to generate a random number identifying the tag, to compare the third parameter to the first parameter, and to communicate a reply signal to the interrogation signal via the antenna it in part, the third parameter matches the first parameter and the second parameter matches the value, wherein the reply signal is configured to be modulated using a selected one of a plurality of modulation types as set by the return link configuration information, and, in accordance with one of the plurality of modulation types, a baseband waveform is configured to be multiplied by a selected one of three different pulse waveforms as set by the retum link configuration information; and a host computer coupled to the interrogator to receive and process the identification code. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. An RFID system, comprising:
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a first interrogator configured to transmit a first interrogation signal to perform collision arbitration, the first interrogation signal comprising a first parameter, a second parameter, a third parameter that is equal to the first parameter, and return link configuration information; a second interrogator configured to transmit a second interrogation signal to perform collision arbitration; a plurality of items to be managed, each respective item of the plurality of items having affixed thereto a respective label, each respective label having a respective front side and a respective back side; and a plurality of RFID tags, each respective RFID tag of the plurality of RFID tags affixed to the back side of a respective label, each respective RFID tag comprising a respective antenna disposed on a respective plastic substrate and a respective integrated circuit storing a respective identification code associated with a respective item, wherein each respective tag is configured to receive the interrogation signal, to compare the second parameter to a value stored in the respective integrated circuit other man the respective identification code, to independently generate a respective random number identifying the respective tag, to compare the third parameter to the first parameter to distinguish the first interrogator from the second interrogator, and to communicate a respective reply signal to the first interrogator if, at least in part, the third parameter matches the first parameter and the second parameter matches the respective value, wherein the respective reply signal is configured to be modulated using one of a plurality of modulation types selected by the first interrogator, and wherein in accordance with the one of the plurality of modulation types, a bit is configured to be represented by a selected one of three different waveform sequence lengths selected by the first interrogator. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40)
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41. A system, comprising:
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a first interrogator configured to transmit a first interrogation signal to implement collision arbitration; a second interrogator configured to transmit a second interrogation signal to implement collision arbitration, the second interrogation signal comprising a first parameter, a second parameter, a third parameter equal to the first parameter for use in distinguishing the second interrogation signal from the first interrogation signal, and return link configuration information; a host computer coupled to the first and second interrogators, a plurality of items to be monitored via the host computer; a plurality of labels, each respective label affixed to a respective item and comprising visual information including text formed a respective front side; and an RFID tag attached to a back side of at least one of the labels attached to an item, the tag comprising an antenna disposed on a plastic substrate and an integrated circuit storing an identification code associated with the item, wherein the tag is configured to store a value other than the identification code, to generate a random number identifying the tag, and to communicate a reply signal to the second interrogation signal if, at least in part, the tag determines that the second parameter matches the value and the third parameter matches the first parameter, and wherein the tag is further configured to modulate the reply signal using a selectable one of a plurality of modulation types as set by the return link configuration information, and wherein in accordance with one of the plurality of modulation types, a bit is configured to be represented by a selectable one of at least three different waveform sequences, each of different lengths, as set by the return link configuration information. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
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Specification