Near-field electromagnetic induction (NFEMI) antenna

• US 10,320,086 B2
• Filed: 05/04/2016
• Issued: 06/11/2019
• Est. Priority Date: 05/04/2016
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Kerselaers, Anthony, Gomme, Liesbeth
• Primary Examiner(s): Han, Jessica
• Assistant Examiner(s): Patel, Amal
• Application Number:
  US15/146,665
• Publication Number:
  US 20170324170A1
• Time in Patent Office: 1,133 Days
• 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 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• CPC Class Codes: H01Q 21/0006 Particular feeding systems
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication

Abstract

One example discloses a near-field electromagnetic induction (NFEMI) antenna, including: an electric antenna including a first electrically conductive surface; a magnetic antenna including a first coil (L1) coupled to a second coil (L2); a first feeding connection coupled to one end of the first coil; a second feeding connection coupled to another end of the first coil and one end of the second coil; wherein a another end of the second coil is connected to the electrically conductive surface; and a magnetic permeable material coupled to one side of the magnetic antenna and configured to be placed between the magnetic antenna and a set of electric components.

Claims

1. A near-field electromagnetic induction (NFEMI) antenna, comprising:

an electric antenna including a first electrically conductive planar surface;

a magnetic antenna including a first coil coupled to a second coil;

a first feeding connection coupled to one end of the first coil;

a second feeding connection coupled to another end of the first coil and one end of the second coil;

wherein another end of the second coil is connected to the electrically conductive surface; and

a magnetic permeable material coupled to one side of the magnetic antenna and configured to be placed between the magnetic antenna and a set of electric components;

wherein the first coil is a planar spiral coil; and

wherein the first coil is configured to function as a second electrically conductive surface in the electric antenna by physically facing the first electrically conductive planar surface.

2. The antenna of claim 1:

wherein the magnetic permeable material is configured to shield the set of electronic components from a magnetic field generated by the coils.

3. The antenna of claim 1:

wherein the magnetic permeable material is at least one of;

a planar sheet, a ferrite shield, a ferrite sheet or a coating comprising ferrite particles in suspension.

4. The antenna of claim 1:

wherein the magnetic permeable material is configured to spatially amplify magnetic flux generated by the coils toward a direction opposite from the set of electronic components.

5. The antenna of claim 1:

wherein a position of the first electrically conductive surface is at least one of;

between the set of electronic components and the magnetic permeable material or between the magnetic permeable material and the coils.

6. The antenna of claim 1:

wherein the magnetic permeable material includes an adhesive on one side for adhering to the coils.

7. The antenna of claim 1:

wherein the first electrically conductive surface and the coils are in a stacked configuration, wherein the first electrically conductive surface defines a first end of the stack and the coils define a second end of the stack.

8. The antenna of claim 7:

wherein a position of the magnetic permeable material is at least one of;

between the coils and the first electrically conductive surface;

or at either end of the stack.

9. The antenna of claim 7:

further comprising a substrate configured to physically separate the coils from the electrically conductive surface in the stack.

10. The antenna of claim 9:

wherein the substrate is at least one of;

a dielectric material, a ferrite material, air, plastic or a polymer.

11. The antenna of claim 1:

wherein the first electrically conductive surface includes an open end.

12. The antenna of claim 1:

wherein the first electrically conductive surface is a plate.

13. The antenna of claim 1:

wherein the first electrically conductive planar surface and the planar spiral coil have substantially matching shapes.

14. The antenna of claim 1:

wherein the antenna is positioned on a backside of a mobile device or a wearable device.

15. A wearable device, comprising:

an electric antenna including a first electrically conductive planar surface;

a magnetic antenna including a first coil coupled to a second coil;

a first feeding connection coupled to one end of the first coil;

a second feeding connection coupled to another end of the first coil and one end of the second coil;

wherein another end of the second coil is connected to the electrically conductive surface; and

a magnetic permeable material coupled to one side of the magnetic antenna and configured to be placed between the magnetic antenna and a set of electric components;

wherein the electric and magnetic antennas form a near-field electromagnetic induction (NFEMI) antenna;

wherein the first coil is a planar spiral coil; and

wherein the first coil is configured to function as a second electrically conductive surface in the electric antenna by physically facing the first electrically conductive planar surface.

16. The device of claim 15:

wherein the antenna is embedded in at least one of;

a smart watch;

a smartwatch housing, a wireless mobile device, an earbud, a hearing aid, a headphone, an activity tracker, or a heart rate monitor.

17. The device of claim 15:

wherein the antenna is embedded in a transceiver configured to communicate using near-field electromagnetic induction with another wearable device.

18. The device of claim 15:

wherein the antenna is configured to communicate signals using both magnetic and electric near-field induction.