Dual Use RFID/EAS Device

Abstract

A radio frequency identification (RFID) device has multiple modes of operation. One of the modes of operation is an electronic article surveillance (EAS) mode, which is used to allow use of the RFID device as an EAS device. Another mode of operation is an RFID mode, which allows normal function of the RFID device in RFID communications. The EAS mode has greater sensitivity than the RFID mode, requires less power than the RFID mode to operate the device, and requires less current and/or voltage for operation. The EAS mode may achieve these different characteristics by one or more of: switching off some digital blocks in the circuitry of the RFID device; reducing power storage required to respond to incoming signals; reducing the length of response to incoming signals; reducing modulation required for a response; changing chip input impedance; and having multiple chip ports with different impedances.

1 . A radio frequency identification (RFID) tag, comprising: a chip; and
 an antenna operatively coupled to the chip;   wherein the chip including circuitry for operation between a first mode and a second mode; and   wherein each of the first and second modes operate at a different sensitivity.   
     
     
         2 . The RFID tag of  claim 1 , wherein the chip deactivates either the first or second mode on receipt of a signal. 
     
     
         3 . The RFID tag of  claim 1 , wherein one of the first or second mode is an EAS mode and the a further mode is a RFID mode. 
     
     
         4 . The RFID tag of  claim 3 , wherein the chip uses less power in the EAS mode than in the RFID mode. 
     
     
         5 . The RFID tag of  claim 3 , wherein the circuitry includes circuitry for switching off digital blocks of the circuitry for the EAS mode. 
     
     
         6 . The RFID tag of  claim 1 , wherein the first mode is a relatively low sensitivity RFID mode and the second mode is a relatively high sensitivity EAS mode. 
     
     
         7 . The RFID of  claim 1 , wherein the entering includes reducing power storage required in a chip of the RFID device before communicating with the EAS reader/detector. 
     
     
         8 . A radio frequency identification (RFID) tag, comprising: a chip; and
 at least one antenna coupled to the chip;   wherein the chip includes circuitry for operating at a normal mode and at least a second mode, and wherein the chip selectively operates between the normal mode and the second mode; and   wherein the chip deactivates one of the normal mode and second mode on receipt of a signal.   
     
     
         9 . The RFID tag of  claim 8 , wherein the RFID device is a UHF RFID device. 
     
     
         10 . The RFID tag of  claim 8 , wherein the at least one antenna is coupled to contacts of the chip. 
     
     
         11 . The RFID tag of  claim 8 , wherein the second mode has an improved sensitivity in the normal mode. 
     
     
         12 . The RFID tag of  claim 8 , wherein the normal mode is used for RFID communication. 
     
     
         13 . The RFID tag of  claim 12 , wherein the second mode has an improved sensitivity and is used for communication with an EAS reader/detector. 
     
     
         14 . The RFID tag of  claim 13 , wherein the normal mode requires more power to operate than the second mode. 
     
     
         15 . The RFID tag of  claim 13 , wherein the RFID device has its operation modified in the second mode. 
     
     
         16 . The RFID tag of  claim 13 , wherein the device does not store as much power in the second mode. 
     
     
         17 . The RFID tag of  claim 8 , wherein the chip has a number of digital blocks in its circuitry. 
     
     
         18 . The RFID tag of  claim 17 , wherein the digital blocks include a power storage block. 
     
     
         19 . The RFID tag of  claim 18 , wherein the power storage block includes a charge/pump regulator with at least one capacitor. 
     
     
         20 . A radio frequency identification (RFID) tag, comprising a chip having at least two inputs;
 an EAS antenna coupled to the chip and a RFID antenna coupled to the chip;   the RFID tag can receive signals in one of two modes; and   wherein a signal received by the RFID antenna deactivates the EAS antenna.