RFID system utilizing parametric reflective technology

• US 20050280539A1
• Filed: 06/21/2005
• Published: 12/22/2005
• Est. Priority Date: 06/22/2004
• Status: Active Grant

• Current Assignee: Vubiq Networks, Inc.
• Original Assignee: Vubiq, Inc.
• Inventors: Pettus, Michael Gregory
• Granted Patent: US 7,498,940 B2
• Time in Patent Office: Days
• US Class Current: 340/572.1
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• CPC Class Codes: G01S 13/9064 Inverse SAR [ISAR]
• CPC Class Codes: G01S 13/9076 Polarimetric features in SAR
• CPC Class Codes: G06K 19/067 Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
• CPC Class Codes: G06K 19/0672 with resonating marks
• CPC Class Codes: G06K 7/00 Methods or arrangements for sensing record carriers, e.g. for reading patterns methods or arrangements for marking the record carrier in digital fashion G06K1/00; pattern recognition G06F18/00; arrangements for image or video recognition or understanding G06V10/00; character recognition, recognising digital ink or document-oriented image-based pattern recognition G06V30/00
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 21/062 using dipole aerials; H01Q21/067, H01Q21/068 take precedence
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/245 provided with means for varying the polarisation polarising devices H01Q15/24; tracking by comparing linear polarisation compounds G01S3/146; reducing depolarisation effects H04B7/00; polarisation diversity H04B7/10

Abstract

A system and method for encoding and decoding information by use of radio frequency antennas. The system includes one or more interrogator devices and RFID data tags. The RFID data tags include a plurality of antenna elements which are formed on a substrate or directly on an object. The antenna elements are oriented and have dimensions to provide polarization and phase information, whereby this information represents the encoded information on the RFID tag. The interrogator device scans an area and uses radar imaging technology to create an image of a scanned area. The device receives re-radiated RF signals from the antenna elements on the data tags, whereby the data tags are preferably represented on the image. The re-radiated RF signals preferably include polarization and phase information of each antenna element, whereby the information is utilized using radar signal imaging algorithms to decode the information on the RF data tag.

Claims

1. An RF data tag identification system comprising:

an RF data tag having encoded information, the RF data tag including an antenna element having predetermined phase and polarization parameters; and

at least one interrogating device to transmit electromagnetic radiation and receive re-radiated electromagnetic radiation from the RF data tag, wherein the at least one interrogating device decodes the encoded information from at least one polarization parameter and at least one phase parameter in the received re-radiated electromagnetic radiation. The system of claim 1 wherein the antenna element has an orientation and at least one dimension associated with the polarization and phase parameters.

2. The system of claim 1 wherein the RF data tag further comprises a reference antenna element, wherein the reference antenna element is separated from the antenna element by at least one-half wavelength.

3. The system of claim 1 wherein at least one of the interrogating device and RF data tag is moving.

4. The system of claim 1 wherein the interrogating device determines the polarization and phase parameters from the re-radiated electromagnetic radiation using a radar image signal processing algorithm.

5. The system of claim 1 further comprising a display coupled to the interrogating device which produces an image of an area scanned from the electromagnetic radiation transmitted and received, wherein the image includes at least one of a location and identity of the RF data tag.

6. The system of claim 1 further comprising a plurality of interrogating devices coupled to one another, wherein at least one interrogating device in the plurality provides RF data tag information to at least one other interrogating device in the plurality.

7. The system of claim 6 wherein a first interrogating device transmits electromagnetic radiation and the plurality of interrogating devices receive the re-radiated electromagnetic radiation simultaneously.

8. The system of claim 6 wherein a first interrogating device transmits electromagnetic radiation and the plurality of interrogating devices receive the re-radiated electromagnetic radiation in a desired sequence.

9. The system of claim 6 wherein a plurality of interrogating devices transmit electromagnetic radiation sequentially and the plurality of interrogating devices receive the re-radiated electromagnetic radiation simultaneously.

10. The system of claim 6 wherein a plurality of interrogating devices transmit electromagnetic radiation in a first sequence and the plurality of interrogating devices receive the re-radiated electromagnetic radiation in a second sequence.

11. An RF data tag encoded to contain information comprising a plurality of antenna elements adapted to receive incident electromagnetic radiation, the antenna elements each having phase and polarization parameters indicative of encoded information, wherein at least one antenna element re-radiates electromagnetic radiation having the phase and polarization parameters representative of the encoded information.

12. The data tag of claim 11 wherein the antenna elements are printed in conductive ink.

13. The data tag of claim 11 wherein at least one of the antenna elements is a reference antenna element having known phase and polarization parameters.

14. The data tag of claim 11 wherein the antenna elements are separated from one another by at least one-half of a wavelength.

15. The data tag of claim 11 wherein each antenna element has an orientation and at least one dimension associated with the polarization and phase parameters.

16. The data tag of claim 11 wherein the antenna elements are disposed on a substrate.

17. The data tag of claim 11 wherein the antenna elements are adapted to be directly printed in conductive ink on an object.

18. An interrogator device to decode information encoded in an RF data tag, the interrogator device comprising:

a. an antenna structure to transmit electromagnetic radiation, wherein the antenna structure is adapted to sense re-radiated electromagnetic radiation from an RF data tag;

b. a first circuit to determine at least polarization and phase information from the sensed electromagnetic radiation; and

c. a second circuit to convert the polarization and phase information into machine readable data representative of information encoded in the RF data tag.

19. The device of claim 18 wherein the first circuit performs radar image signal processing to determine the polarization and phase information.

20. The device of claim 18 wherein the interrogator transmits a plurality of electromagnetic radiation scans at a desired frequency, wherein the electromagnetic radiation in at least one scan is transmitted having a polarization parameter different than a polarization parameter in another scan in the plurality.