SYSTEMS AND METHODS FOR CONTROLLING RADIO-FREQUENCY IDENTIFICATION (RFID) TAG COMMUNICATION
First Claim
1. A radio-frequency identification (RFID) tag comprising:
- an antenna;
at least one discrete circuit component that is connected to the antenna and that contributes to an impedance of the RFID tag, which is variable;
at least one switch connected to the at least one discrete circuit component;
a receiver that receives a control signal from an RFID reader; and
a controller connected to the at least one switch and, in response to the RFID tag receiving the control signal from the RFID reader, operates the switch between open and closed states to change the impedance of the RFID tag between a first modulating impedance value and a second modulating impedance value and a signal that is transmitted from the RFID tag is different depending on the switch state,wherein an initiation signal is sent, by an RFID reader, to a first RFID tag being the RFID tag and also to a second RFID tag to set impedances of the first and second RFID tags to a default value, and the control signal is sent to the first RFID tag instructing the impedance of the first RFID tag to be switched but the control signal is not sent to the second RFID tag, so that the first RFID tag has an impedance that differs from the second RFID tag based on the control signal.
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Accused Products
Abstract
Systems and methods for radio-frequency identification (RFID) tag communication are provided. One radio-frequency identification (RFID) tag includes a communication device configured to communicate with an RFID reader and an impedance element configured to change an variable impedance of the RFID tag. The RFID tag further includes at least one switch connected to the impedance element and a controller connected to the at least one switch and configured to control operation of the switch between open and closed states based on a control signal received from the RFID reader, wherein the variable impedance of the RFID tag is changed between a first modulating impedance value and a second modulating impedance value when the switch is changed between the open and closed states.
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Citations
20 Claims
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1. A radio-frequency identification (RFID) tag comprising:
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an antenna; at least one discrete circuit component that is connected to the antenna and that contributes to an impedance of the RFID tag, which is variable; at least one switch connected to the at least one discrete circuit component; a receiver that receives a control signal from an RFID reader; and a controller connected to the at least one switch and, in response to the RFID tag receiving the control signal from the RFID reader, operates the switch between open and closed states to change the impedance of the RFID tag between a first modulating impedance value and a second modulating impedance value and a signal that is transmitted from the RFID tag is different depending on the switch state, wherein an initiation signal is sent, by an RFID reader, to a first RFID tag being the RFID tag and also to a second RFID tag to set impedances of the first and second RFID tags to a default value, and the control signal is sent to the first RFID tag instructing the impedance of the first RFID tag to be switched but the control signal is not sent to the second RFID tag, so that the first RFID tag has an impedance that differs from the second RFID tag based on the control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A radio-frequency identification (RFID) system comprising:
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a first RFID tag comprising; an impedance element configured to change an impedance value of the RFID tag; and a controller connected to the impedance element and configured to dynamically adjust the modulating impedance value by controlling operation of the impedance element; and a second RFID tag, wherein the control signal is sent to the first RFID tag instructing the impedance of the first RFID tag to be adjusted but the control signal is not sent to the second RFID tag, so that the first RFID tag has an impedance that differs from the second RFID tag based on the control signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A method comprising:
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sending a first signal to a first RFID tag and a second RFID tag to set a modulating impedance value for each of the first and second RFID tags using one or more broadcast command signals; and sending a control signal, from an RFID reader, to the first RFID tag, but not the second RFID tag, instructing the impedance value of the first RFID tag to be changed in response to a detected backscatter collision between signals from the first and second RFID tags received by the RFID reader at the same time. - View Dependent Claims (20)
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Specification