RFID devices using metamaterial antennas

• US 8,944,330 B2
• Filed: 09/06/2013
• Issued: 02/03/2015
• Est. Priority Date: 03/04/2011
• Status: Expired due to Fees

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Wang, Ynjiun Paul, Qu, Huyu
• Primary Examiner(s): VO, TUYEN KIM
• Application Number:
  US14/019,968
• Publication Number:
  US 20140008437A1
• Time in Patent Office: 515 Days
• Field of Search: 235/375, 235/451, 235/462.14, 235/462.25, 235/462.45, 23547201-47203, 235/492, 343/700.MS
• 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;

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

wherein an equivalent circuit for the patch cell stack comprises;

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

at least two shunt inductances,

wherein the antenna is configured to support a plurality of frequency bands, each frequency band of the plurality of frequency bands having a center frequency, and

wherein the antenna has a size of a portion of a wavelength corresponding to a maximum of the center frequencies.

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

3. The RFID tag of claim 1, wherein the antenna has a size of less or equal to one tenth of a wavelength corresponding to a maximum of the center frequencies.

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

7. An apparatus comprising:

a communication interface;

an RFID reader comprising an antenna provided by a patch cell stack comprising two or more patch cells;

wherein an equivalent circuit for the patch cell stack comprises;

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

at least two shunt inductances,

wherein the antenna is configured to support a plurality of frequency bands, each frequency band of the plurality of frequency bands having a center frequency.

8. The apparatus of claim 7, wherein the antenna has a size less than or equal to one tenth of a wavelength corresponding to a maximum of the center frequencies.

9. The apparatus of claim 7, wherein the 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 apparatus of claim 7, wherein the patch cell stack includes two or more patch cells disposed vertically in a plane perpendicular to the patch cells.

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

an antenna provided by a patch cell stack comprising two or more patch cells disposed vertically in a plane perpendicular to the patch cells;

a feed line electrically coupled to the antenna;

wherein an equivalent circuit for the patch cell stack comprises;

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

at least two shunt inductances,

wherein the antenna is configured to support a plurality of frequency bands, each frequency band of the plurality of frequency bands having a center frequency.

12. The RFID tag of claim 11, wherein the RFID chip comprises a radio frequency (RF) front end and a memory.

13. The RFID tag of claim 11, wherein the antenna has a size of less or equal to one tenth of a wavelength corresponding to a maximum of the center frequencies.

14. The RFID tag of claim 11, wherein the feed line is provided by one of:

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

15. The RFID tag of claim 11, further comprising a battery.