RFID system and communication method performed by the same
First Claim
1. A radio frequency identification (RFID) system comprising:
- an RFID tag; and
an RFID reader having a signal strength measurer that measures a strength of a signal received from the RFID tag, the RFID reader is configured to create control information used to set an amplification amount of the RFID tag using a value of the measured strength, include the control information in a first output signal, and send the first output signal to the RFID tag;
wherein the RFID tag, if the signal sent from the RFID reader is received, extracts internal information in response to the received signal, sends the information to the RFID reader as a second output signal, extracts the control information included in the received signal sent from the RFID reader, and adjusts a strength of the second output signal according to a value contained within the control information, whereinif the strength of the signal received from the RFID tag is below a first predetermined value, the RFID reader sets the control information so that the amplification amount of the RFID tag is increased, andif the strength of the signal received from the RFID tag is above a second predetermined value, the RFID reader sets the control information so that the amplification amount of the RFID tag is reduced.
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Accused Products
Abstract
Provided is an RFID system and method for maintaining a constant strength of a signal transmitted from an RFID tag to an RFID reader, regardless of a distance between the reader and tag. The RFID signal strength measuring reader measures a signal strength received from the RFID tag, creates control information used to set an amplification amount of the RFID tag by using a value of the measured strength to include the control information in an output signal, and sends the output signal to the RFID tag. The RFID tag, if the signal sent from the RFID reader is received, extracts internal information from the received signal, sends the information to the RFID reader as an output signal, and extracts the control information included in the signal sent from the RFID reader to adjust a strength of the output signal according to a value of the control information.
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Citations
14 Claims
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1. A radio frequency identification (RFID) system comprising:
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an RFID tag; and an RFID reader having a signal strength measurer that measures a strength of a signal received from the RFID tag, the RFID reader is configured to create control information used to set an amplification amount of the RFID tag using a value of the measured strength, include the control information in a first output signal, and send the first output signal to the RFID tag; wherein the RFID tag, if the signal sent from the RFID reader is received, extracts internal information in response to the received signal, sends the information to the RFID reader as a second output signal, extracts the control information included in the received signal sent from the RFID reader, and adjusts a strength of the second output signal according to a value contained within the control information, wherein if the strength of the signal received from the RFID tag is below a first predetermined value, the RFID reader sets the control information so that the amplification amount of the RFID tag is increased, and if the strength of the signal received from the RFID tag is above a second predetermined value, the RFID reader sets the control information so that the amplification amount of the RFID tag is reduced.
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2. A radio frequency communication system comprising:
a first device configured to transmit a wireless signal; and a second device configured to receive the wireless signal and send information to the first device by modulating the received wireless signal; wherein the second device sends control information including a digital value to the first device, and the first device, if the control information sent from the second device is received, extracts the digital value from the control information, and controls the transmission of the wireless signal according to the digital value contained within the control information, wherein if the strength of the wireless signal transmitted from the first device to the second device is below a first predetermined value, the second device sets the digital value of the control information so that the amplification amount of the first device is increased, and if the strength of the wireless signal transmitted from the first device to the second device is above a second predetermined value, the second device sets the digital value of the control information so that the amplification amount of the first device is reduced. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
Specification