RFID WITH PHASE ROTATED BACKSCATTERING AND METHODS FOR USE THEREWITH

• US 20090201134A1
• Filed: 01/12/2009
• Published: 08/13/2009
• Est. Priority Date: 02/08/2008
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Ahmadreza (Reza)
• Application Number:
  US12/352,396
• Publication Number:
  US 20090201134A1
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07775 the antenna being on-chip
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: H04M 1/72412 using two-way short-range wireless interfaces
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

A radio frequency identification (RFID) device includes an antenna coupled to receive a millimeter wave RFID signal from a remote RFID reader. A phase rotation module generates a phase rotated backscatter signal, based on the millimeter wave RFID signal and further based on a phase rotation signal that identifies the RFID device.

Claims

1. An radio frequency identification (RFID) device comprising:

an antenna coupled to receive a millimeter wave RFID signal from a remote RFID reader;

a phase rotation module, coupled to the antenna, that generates a phase rotated backscatter signal, based on the millimeter wave RFID signal and further based on a phase rotation signal that identifies the RFID device.

2. The RFID device of claim 1 wherein the phase rotation module includes an adjustable impedance.

3. The RFID device of claim 2 wherein the adjustable impedance includes at least one of an adjustable capacitance;

and an adjustable inductance.

4. The RFID device of claim 2 wherein the phase rotation module includes phase rotation controller that generates the phase rotation signal to control the adjustable impedance.

5. The RFID device of claim 1 further comprising:

a power generating circuit, coupled to the antenna and the phase rotation module, that generates at least one power supply signal based on the millimeter wave RFID signal;

wherein the phase rotation module is powered based on the power supply signal.

6. The RFID device of claim 5 further comprising:

an additional power source, coupled to the phase rotation module, for selectively powering the phase rotation module;

wherein the power generating circuit is selectively disabled when the additional power source powers the phase rotation module.

7. The RFID device of claim 1 further comprising:

a modulation module, coupled to the antenna, that modulates the phase rotated backscatter signal based on RFID data.

8. An radio frequency identification (RFID) reader comprising:

an antenna;

a transmitter section, coupled to the antenna, that transmits a millimeter wave RFID signal to a first remote RFID device;

a receiver section, coupled to the antenna, that receives a first phase rotated backscatter signal from the first remote RFID device, and recovers a first phase rotation signal from the phase rotated backscatter signal to identify the first remote RFID device.

9. The RFID reader of claim 8, wherein the transmitter section further transmits the millimeter wave RFID signal to a second remote RFID device;

and

wherein the receiver section further receives a second phase rotated backscatter signal from the second remote RFID device, and recovers a second phase rotation signal from the phase rotated backscatter signal to identify the second remote RFID device.

10. The RFID reader of claim of claim 8 wherein the receiver section demodulates the first phase rotated backscatter signal to recover RFID data sent from the first remote RFID device.

11. A method comprising:

receiving a millimeter wave RFID signal from a remote RFID reader;

generating a phase rotated backscatter signal, based on the millimeter wave RFID signal and further based on a phase rotation signal that identifies the RFID device.

12. The method of claim 11 wherein generating the phase rotated backscatter signal includes adjusting an adjustable impedance.

13. The method of claim 12 wherein the adjustable impedance includes at least one of an adjustable capacitance;

and an adjustable inductance.

14. The method of claim 12 wherein generating the phase rotated backscatter signal includes generating the phase rotation signal to adjust the adjustable impedance.

15. The method of claim 11 further comprising:

generating at least one power supply signal based on the millimeter wave RFID signal.

16. The method of claim 15 wherein generating the at least one power supply signal includes selectively generating the at least one power supply signal when an additional power source is absent.

17. The method of claim 11 wherein generating the phase rotated backscatter signal includes modulating the phase rotated backscatter signal based on RFID data.

18. A method comprising:

transmitting a millimeter wave RFID signal to a first remote RFID device;

receiving a first phase rotated backscatter signal from the first remote RFID device; and

recovering a first phase rotation signal from the phase rotated backscatter signal to identify the first remote RFID device.

19. The method of claim 18, further comprising:

transmitting the millimeter wave RFID signal to a second remote RFID device;

receiving a second phase rotated backscatter signal from the second remote RFID device; and

recovering a second phase rotation signal from the phase rotated backscatter signal to identify the second remote RFID device.

20. The method of claim of claim 18 further comprising:

demodulating the first phase rotated backscatter signal to recover RFID data sent from the first remote RFID device.