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 signal strength measuring reader that measures a strength of a signal 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;
wherein 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 at this time, 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.
3 Assignments
0 Petitions
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.
-
Citations
23 Claims
-
1. A radio frequency identification (RFID) system comprising:
-
an RFID tag; and an RFID signal strength measuring reader that measures a strength of a signal 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; wherein 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 at this time, 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. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A communication method performed by a RFID system comprising an RFID reader and an RFID tag, the method comprising:
-
if a signal sent from the RFID tag is received, then measuring a strength of the received signal, wherein the RFID reader measures the strength; creating control information used to set an amplification amount of an output signal of the RFID tag by using a value of the measured strength, wherein the RFID reader creates the control information; and sending a signal including the control information to the RFID tag, wherein the RFID reader sends the signal. - View Dependent Claims (9)
-
-
10. A communication method performed by an RFID system comprising an RFID reader and an RFID tag, the method comprising:
if a signal sent from the RFID reader is received, then checking if control information used to set an amplification amount of the RFID tag is included in the received signal, wherein the RFID tag performs checking; if the control information is included in the received signal, then extracting the control information and information stored in the RFID tag and modulating the extracted information, wherein the RFID tag performs extraction; and amplifying the modulated signal, and adjusting and outputting an amplification amount of the modulated signal according to a value of the control information, wherein the RFID tag performs amplification and adjustment. - View Dependent Claims (11)
-
12. An RFID tag that communicates with an RFID reader wirelessly, the RFID tag comprising:
-
a signal strength measuring unit that receives a signal from the RFID reader and measures a strength of the received signal; and an output unit that receives a signal that is output from the signal strength measuring unit, adjusts a strength of an RFID tag signal, and sends the RFID tag signal to the RFID reader. - View Dependent Claims (13, 14, 15, 16, 17)
-
-
18. An RFID tag that communicates with an RFID reader, the RFID tag comprising:
-
an antenna that receives and sends a signal from and to the RFID reader; a signal strength measuring unit that receives the signal from the RFID reader and measures a strength of the received signal; a variable amplification unit that amplifies an input signal, receives an output signal of the signal strength measuring unit, adjusts an amplification amount of the input signal, and outputs the adjusted signal; and a circulator connected to the variable amplification unit, the signal strength measuring unit, and the antenna, that transmits the signal which is output from the variable amplification unit to the antenna, and sends the signal which is output via the antenna to the signal strength measuring unit. - View Dependent Claims (19, 20, 21)
-
-
22. A method of operating an RFID tag that communicates with an RFID reader, the method comprising:
-
measuring a strength of a signal sent from the RFID reader and outputting the signal as a control signal; extracting information stored in the RFID tag; modulating a signal of the extracted information; and adjusting a strength of the modulated signal according to the control signal and sending the modulated signal to the RFID reader. - View Dependent Claims (23)
-
Specification