Dual use RFID/EAS device
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) device comprising:
a chip having a first set of contacts and a second set of contacts;
a first antenna for connection to the first set of contacts;
a second antenna for connection to the second set of contacts;
wherein the chip includes circuitry to selectively operate the RFID device two modes:
a relatively low sensitivity RFID mode used for communicating with RFID readers/detectors;
a relatively high sensitivity electronic article surveillance (EAS) mode for communicating as EAS readers detectors; and
wherein at least one of the first or second set of contacts is configured with a very high input capacitance and a high real part of the impedance.
2. The RFID device of claim 1 , wherein the first set of contacts and the first antenna are used for communication in the RFID mode.
3. The RFID device of claim 2 , wherein the second set of contacts and the second antenna are used for communication in the EAS mode.
4. The RFID device of claim 1 , wherein the first set of contacts and the first antenna are used for communication in the EAS mode.
5. The RFID device of claim 4 , wherein the second set of contacts and the second antenna are used for communication in the RFID mode.
6. The RFID device of claim 1 , wherein the first set of contacts has different impedance than the second set of contacts.
7. The RFID device of claim 1 , wherein the chip uses less power from a power storage block in the EAS mode than in the RFID mode.
8. The RFID device of claim 1 , wherein the one of the first and second set of contacts is the second set of contacts.
9. The RFID device of claim 1 , wherein the one of the first and second set of contacts is the first set of contacts.
10. The RFID device of claim 1 , wherein the RFID device is a UHF RFID device.
11. The RFID device of claim 1 , wherein the device is set to respond in EAS mode.
12. The RFID device of claim 1 , wherein the device is set to respond in RFID mode.
13. The RFID device of claim 1 , wherein the chip deactivates either the RFID mode or the EAS mode on receipt of a signal.
14. The RFID device of claim 1 , wherein the RFID device is embodied as a label or tag.
15. The RFID device of claim 1 , wherein the RFID device further comprises an adhesive layer.
16. A method of utilizing an RFID device for use as an electronic article surveillance (EAS) device, the method comprising:
entering an improved sensitivity mode of operation that improves sensitivity over that of a normal mode of operation that is used for RFID communication;
while in the improved sensitivity mode, communicating with an EAS mode; and
wherein the RFID device includes a chip having a first set of contacts and a second set of contacts, a first antenna for connection to the first set of contacts,
a second antenna for connection to the second set of contacts;and
wherein at least one of the first or second set of contacts is configured with a very high input capacitance and a high real part of the impedance.
17. The method of claim 16 , wherein the entering includes switching off digital blocks in circuitry of the RFID device.
18. The method of claim 16 , wherein the first antenna and the second antenna are dipole antennas.
19. The method of claim 16 , wherein the first antenna and the second antenna are loop antennas.
20. The method of claim 16 , wherein the first antenna and the second antenna are slot antennas.