RFID devices using metamaterial antennas

• US 8,556,178 B2
• Filed: 03/04/2011
• Issued: 10/15/2013
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Wang, Ynjiun P., Qu, Huyu
• Primary Examiner(s): VO, TUYEN KIM
• Application Number:
  US13/041,165
• Publication Number:
  US 20120223142A1
• Time in Patent Office: 956 Days
• Field of Search: 235/375, 235/451, 235/492, 235/439, 340/10.1, 340/10.2, 340/572.1, 340/572.2, 340/572.7, 343/700.MS, 343/700.R, 343/853
• US Class Current: 235/462.25
• CPC Class Codes: G06K 19/07754 the connection being galvanic
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/07788 the antenna being of the capacitive type
• CPC Class Codes: G06K 7/10326 the antenna being of the very-near field type, e.g. capacitive
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials

Abstract

A radio frequency identifier (RFID) tag can comprise an RFID chip, an antenna, and a feed line electrically coupling the RFID chip to the antenna. An encoded information reading (EIR) terminal can comprise a microprocessor, a memory communicatively coupled to the microprocessor, a communication interface, and an EIR device provided by a bar code reading device, an RFID reading device, or a card reading device. The RFID reading device can further comprise an antenna and a feed line. The antenna for the RFID tag or for the RFID reading device can be provided by a patch cell, a patch cell array comprising two or more patch cells, or by a patch cell stack comprising two or more patch cells. An equivalent circuit for the patch can comprise at least two inductances and a shunt capacitance. An equivalent circuit for the patch cell array can comprise two or more inductance groups connected via a series capacitance and two or more shunt capacitances. An equivalent circuit for the patch cell stack can comprises two or more capacitances connected via a series inductance and two or more shunt inductances. The antenna can have a composite right- and left-handed (CRLH) structure.

Claims

1. A radio frequency identifier (RFID) tag comprising:

an RFID chip;

an antenna provided by a patch cell stack comprising two or more patch cells, wherein said antenna is configured to support one or more frequency bands, each frequency band of said one or more frequency bands having a center frequency, and wherein said antenna has a size of less or equal to one tenth of a maximum of said center frequencies; and

a feed line electrically coupling said RFID chip to said antenna;

wherein an equivalent circuit for said patch cell stack comprises;

at least two capacitances, each of the at least two capacitances connected to each additional capacitance of the at least two capacitances via a series inductance;

at least two shunt inductances; and

wherein said antenna has a composite right-and left-handed (CRLH) structure.

2. The RFID tag of claim 1, wherein said RFID chip comprises a radio frequency (RF) front end and a memory.

3. The RFID tag of claim 1, wherein said antenna is configured to support one or more frequency bands.

4. The RFID tag of claim 1, wherein said feed line is provided by one of:

a monopole, a micro metal stripe, a coaxial cable, a twin parallel wire, a coplanar waveguide.

5. The RFID tag of claim 1, further comprising a battery.

6. The RFID tag of claim 1, wherein said patch cell stack includes two or more patch cells disposed vertically in a plane perpendicular to said patch cells.

7. An encoded information reading (EIR) terminal comprising:

a microprocessor;

a memory communicatively coupled to said microprocessor; and

an EIR device comprising an RFID reading device, said EIR device configured to perform at least one of;

outputting raw message data comprising an encoded message and outputting decoded message data corresponding to an encoded message;

a communication interface;

wherein said RFID reading device further comprises an antenna provided by a patch cell stack comprising two or more patch cells

wherein said antenna is configured to support one or more frequency bands, each frequency band of said one or more frequency bands having a center frequency,

wherein said antenna has a size of less or equal to one tenth of a wavelength corresponding to a maximum of said center frequencies;

wherein an equivalent circuit for said patch cell stack comprises;

at least two capacitances, each of the at least two capacitances connected to each additional capacitance of the at least two capacitances via a series inductance; and

at least two shunt inductances; and

wherein said antenna has a composite right-and left-handed (CRLH) structure.

8. The encoded information reading (EIR) terminal of claim 7, wherein said antenna is configured to support one or more frequency bands.

9. The encoded information reading (EIR) terminal of claim 7, wherein said feed line is provided by one of:

a monopole, a micro metal stripe, a coaxial cable, a twin parallel wire, a coplanar waveguide.

10. The EIR terminal of claim 7, wherein said patch cell stack includes two or more patch cells disposed vertically in a plane perpendicular to said patch cells.

11. A radio frequency identifier (RFID) tag comprising:

an RFID chip;

an antenna provided a patch cell array comprising one or more patch cells;

a feed line electrically coupling said RFID chip to said antenna;

wherein an equivalent circuit for said patch cell array comprises;

at least one inductance group comprising at least two series inductances;

at least one shunt capacitance;

wherein said antenna has a composite right-and left-handed (CRLH) structure;

wherein said antenna is configured to support one or more frequency bands, each frequency band of said one or more frequency bands having a center frequency; and

wherein said antenna has a size of less or equal to one tenth of a wavelength corresponding to a maximum of said center frequencies.

12. The RFID tag of claim 11, wherein said equivalent circuit for said patch cell array further comprises one or more shunt inductances.

13. The RFID tag of claim 11, wherein said patch cell array comprises two or more patch cells;

wherein said at least one inductance group is provided by two or more inductance groups connected via a series capacitance; and

wherein said at least one shunt capacitance is provided by two or more shunt capacitances.

14. The RFID tag of claim 13, wherein said antenna has a gain, said gain increasing with increasing the number of said patch cells.

15. The RFID tag of claim 13, wherein each patch cell of said two or more patch cells further comprises a patch suspended over a ground plane.

16. The RFID tag of claim 13, wherein each patch cell of said two or more patch cells further comprises a patch electrically coupled to a ground plane.

17. The RFID tag of claim 13, wherein said patch cell array comprises two or more patches electrically coupled to a ground plane.

18. An encoded information reading (EIR) terminal comprising:

a microprocessor;

a memory communicatively coupled to said microprocessor;

an EIR device selected from the group consisting of;

a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform at least one of;

outputting raw message data comprising an encoded message and outputting decoded message data corresponding to an encoded message;

a communication interface;

wherein said RFID reading device further comprises an antenna provided by a patch cell array comprising one or more patch cells;

wherein an equivalent circuit for said patch cell array comprises;

at least one inductance group comprising at least two series inductances;

at least one shunt capacitance;

wherein said antenna has a composite right-and left-handed (CRLH) structure;

wherein said antenna is configured to support one or more frequency bands, each frequency band of said one or more frequency bands having a center frequency; and

wherein said antenna has a size of less or equal to one tenth of a wavelength corresponding to a maximum of said center frequencies.

19. The encoded information reading (EIR) terminal of claim 18, wherein said equivalent circuit for said patch cell array further comprises one or more shunt inductances.

20. The encoded information reading (EIR) terminal of claim 18, wherein said patch cell array comprises two or more patch cells;

wherein said at least one inductance group is provided by two or more inductance groups connected via a series capacitance; and

wherein said at least one shunt capacitance is provided by two or more shunt capacitances.

21. The encoded information reading (EIR) terminal of claim 20, wherein said antenna has a gain, said gain increasing with increasing the number of said patch cells.

22. The encoded information reading (EIR) terminal of claim 20, wherein each patch cell of said two or more patch cells further comprises a patch suspended over a ground plane.

23. The encoded information reading (EIR) terminal of claim 20, wherein each patch cell of said two or more patch cells further comprises a patch electrically coupled to a ground plane.

24. The encoded information reading (EIR) terminal of claim 20, wherein said patch cell array comprises two or more patches electrically coupled to a ground plane.