Multiplexing Radio Frequency Signals

• US 20090284354A1
• Filed: 05/19/2008
• Published: 11/19/2009
• Est. Priority Date: 05/19/2008
• Status: Active Grant

• Current Assignee: Neology Incorporated (OEP Technologie BV)
• Original Assignee: Sirit Technologies, Inc.
• Inventors: Pinkham, Jason
• Granted Patent: US 8,446,256 B2
• Time in Patent Office: Days
• US Class Current: 340/10.300
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

The present disclosure is directed to a system and method for multiplexing radio frequency signals. In some implementations, a system includes a host coupling module, a plurality of antennas, and a processing module. The host coupling module is configured to receive and transmit RF signals through a wired connection. The plurality of antennas are configured to wirelessly transmit RF signals and receive RF signals from RFID tags. The processing module is configured to selectively switch between the plurality of antennas for communication with the RFID tags using the host coupling module and backscatter at least a portion of the received RF signals through the wired connection to communicate information independent of an internal power supply.

Claims

1. A radio frequency identification (RFID) multiplexer comprising:

a host coupling module configured to receive and transmit RF signals through a wired connection;

a plurality of antennas configured to wirelessly transmit RF signals and receive RF signals from RFID tags; and

a processing module configured to selectively switch between the plurality of antennas for communication with the RFID tags using the host coupling module and backscatter at least a portion of the received RF signals through the wired connection to communicate information independent of an internal power supply.

2. The RFID multiplexer of claim 1, wherein the wired connection comprises a single wired connection to a host RF transceiver.

3. The RFID multiplexer of claim 1, wherein the RFID multiplexer operates based on power from RF signals received through the wired connection and operates without an internal power supply.

4. The RFID multiplexer of claim 1, the processing module further configured to demodulate at least a portion of the received RF signals to produce baseband frequency signals.

5. The RFID multiplexer of claim 1, wherein the backscattered signal at least identifies information associated with one or more operating parameters of the RFID multiplexer.

6. The RFID multiplexer of claim 5, wherein the one or more parameters comprises a power level of the received RF signals.

7. The RFID multiplexer of claim 1, further comprising a tag emulator module configured to emulate an RFID tag such that the backscattered signal is transmitted in accordance with an RFID protocol.

8. The RFID multiplexer of claim 1, the communication module further configured to generate power for operating the multiplexer based, at least in part, on at least a portion of the received RF signals.

9. The RFID multiplexer of claim 1, the communication module further configured to at least amplitude modulate or phase modulate to backscatter data.

10. The RFID multiplexer of claim 1, further comprising a control module configured to selectively switch between the plurality of antennas based, at least in part, on the received RF signals.

11. The RFID multiplexer of claim 1, further comprising a power tap module configured to detect a DC signal component of the received RF signals and generate power for operating the RFID multiplexer based, at least in part, on the detected DC signal component.

12. The RFID multiplexer of claim 1, further comprising a DC power module configured to convert AC power signals from external supply to DC power signals.

13. The RFID multiplexer of claim 1, wherein the wired connection separates the RFID multiplexer from an RFID host transceiver by 5 feet (ft.) or more.

14. The RFID multiplexer of claim 1, wherein the RFID multiplexer is connected to a different RFID multiplexer through a different single wired connection such that RF signals from a RFID host transceiver can be passed to the different RFID multiplexer.

15. The RFID multiplexer of claim 14, wherein the single wired connection and the different single wired connection comprise coaxial cables.

16. A radio frequency identification (RFID) multiplexer, comprising:

a port configured to receive RF signals from an RFID host;

a plurality of antennas configured to transmit at least a portion of the received RF signals, at least one of the transmitter modules coupled to the host coupling module;

a communication module configured to demodulate at least a portion of the received RF signals to baseband frequency signals and to convert at least a portion of the received RF signals to power signals; and

a control module configured to receive power based, at least in part, on the power signals and to selectively switch connections between the port and the plurality of antennas based at least in part on the baseband frequency signals.

17. The RFID multiplexer of claim 16, the communication module configured to backscatter at least a portion of the received RF signals to the RFID host transceiver through the port.

18. The RFID multiplexer of claim 16, the communication module configured to convert at least a portion of the received RF signals to power signals by rectifying at least the portion of received RF signals to direct current (DC) signals.

19. A method of controlling an RFID multiplexer, comprising:

receiving RF signals through a single wired connection;

selectively switching connections between the single wired connection and a plurality of antennas based, at least in part, on the received RF signals;

transmitting at least a portion of the received RF signals to at least one of the plurality of antennas for wirelessly transmitting the at least a portion to an associated interrogation zone; and

backscattering at least a portion of the received RF signals in response to at least identifying requests for information.

20. The method of claim 19, further comprising:

demodulating at least a portion of the received RF signals to baseband frequency signals; and

selecting one of the plurality of antennas to wirelessly transmit at least a portion of the received RF signals based at least in part on the baseband frequency signals.

21. The method of claim 19, further comprising generating power for operating the RFID multiplexer based, at least in part, the received RF signals.