Patent ID: 8797145

Claim:
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, 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.