Conductive structural members acting as NFC antenna

• US 10,079,922 B2
• Filed: 03/11/2016
• Issued: 09/18/2018
• Est. Priority Date: 03/11/2016
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Yli-Peltola, Ilkka Mikael
• Primary Examiner(s): Huynh, Nam
• Application Number:
  US15/068,513
• Publication Number:
  US 20170264721A1
• Time in Patent Office: 921 Days
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/328 between a radiating element and ground
• 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: H04B 5/43 Antennas
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04M 1/026 Details of the structure or mounting of specific components
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

In an embodiment, conductive structural members of a device acting as NFC antenna are described. According to an embodiment, a device comprises: two conductive structural members, each comprising a first electrical end and a second electrical end, a dielectric isolation being configured between the first electrical end of the first structural member and the first electrical end of the second structural member; two NFC antenna feeds, the first feed being electrically coupled with the first electrical end of the first member, the second feed being electrically coupled with the first electrical end of the second member; two grounding components, one each grounding the second electrical end of the conductive structural members; at least one additional antenna feed configured for a frequency other than that of NFC, coupled to either of the two members.

Claims

1. A device comprising:

two conductive structural members, each comprising a first electrical end and a second electrical end, a dielectric isolation being configured between the first electrical end of the first structural member and the first electrical end of the second structural member;

two near field communication (NFC) antenna feeds, the first feed being electrically coupled with the first electrical end of the first conductive structural member, the second feed being electrically coupled with the first electrical end of the second conductive structural member;

two grounding components, one grounding the first conductive structural member using a first inductor and one grounding the second conductive structural member using a second inductor, wherein each of the two grounding components is configured to selectively ground currents corresponding to frequencies other than frequencies corresponding to NFC;

a third inductor being configured between the second electrical end of the first conductive structural member and the second electrical end of the second conductive structural member, the third inductor configured to block currents corresponding to frequencies higher than frequencies corresponding to NFC; and

at least one additional antenna feed configured for a frequency other than that of NFC, coupled to either of the two conductive structural members.

2. The device of claim 1, wherein the conductive structural members comprise a device cover.

3. The device of claim 2, wherein the conductive structural members are configured around the edges of the device.

4. The device of claim 1, wherein the antenna feeds are configured to feed currents to the conductive structural members in opposite directions.

5. The device of claim 1, the grounding components are positioned such that a substantially annular path is provided to the current in the conductive structural members.

6. The device of claim 1, wherein the grounding components are configured between the conductive structural members and at least one of a chassis comprising the device and a printed circuit board comprising the device.

7. The device of claim 1, wherein the third inductor is configured on a printed wire board.

8. The device of claim 1, wherein the grounding components are configured between the conductive structural members and a chassis at suitable locations to enable operation of NFC without substantial interference.

9. The device of claim 1, wherein the grounding components are structural extensions of the conductive structural members.

10. The device of claim 1, wherein the NFC antenna feeds are coupled to the conductive structural members via inductors.

11. The device of claim 1, wherein the at least one additional antenna feed is coupled to one of the conductive structural members via a capacitor.

12. The device of claim 1, further comprising at least a third grounding component, configured to selectively ground currents corresponding to the at least one additional antenna feed.

13. The device of claim 1, wherein the at least one additional antenna feed is configured for a frequency range suitable for at least one of:

Wireless Local Area Network, FM-Radio, Long Term Evolution Wideband Low Band, Global Navigation Satellite System, Global Positioning System, BeiDou Satellite Navigation System, or a non-cellular wireless system.

14. The device of claim 1, wherein the two conductive structural members are electrically, or physically, or both, joined to each other beyond their second electrical ends.

15. The device of claim 1, wherein the third inductor is a flexible inductor.

16. A device comprising:

an elongate conductive structural member, having two electrical ends in proximity of one another, a dielectric isolation between the two electrical ends;

two near field communication (NFC) antenna feeds, the first feed electrically coupled with the first end of the member, the second feed electrically coupled with the second end of the member;

two grounding components, one each grounding each end of the conductive structural member using an inductor, wherein each of the two grounding components is configured to selectively ground currents corresponding to frequencies other than frequencies corresponding to NFC;

the elongated conductive structural member comprising a further inductor configured to block currents corresponding to frequencies higher than frequencies corresponding to NFC; and

at least one additional antenna feed, configured to a frequency other than that of NFC, coupled to the member.

17. The device of claim 16, wherein the two grounding components are configured to selectively ground the conductive structural member with a printed circuit board such that the current corresponding to the NFC feeds follows a substantially annular path.

18. The device of claim 16, further comprising a capacitive grounding component configured to selectively ground currents corresponding to the at least one additional antenna feed.

19. A method comprising;

placing two conductive structural members each comprising two electrical ends in a device or around the edges of a printed wire board comprising the device, the printed wire board comprising;

two near field communication (NFC) antenna feeds; and

at least one antenna feed calibrated to a frequency other than that of NFC;

coupling each NFC antenna feed to a first end of the two conductive structural members;

two grounding components, one grounding a first conductive structural member using a first inductor and one grounding a second conductive structural member using a second inductor, wherein each of the two grounding components is configured to selectively ground currents corresponding to frequencies other than frequencies corresponding to NFC;

a third inductor being configured between a second electrical end of the first conductive structural member and a second electrical end of the second conductive structural member, the third inductor configured to block currents corresponding to frequencies higher than those of NFC;

coupling the at least one additional antenna feed to either of the two conductive structural members; and

selectively grounding the second ends of the two conductive structural members such that the current corresponding to NFC antenna feeds follows a substantially annular path, and such that currents corresponding to frequencies higher than frequencies corresponding to NFC are grounded.

20. The method of claim 19, wherein the second ends of the two conductive structural members are connected to each other either electrically, physically or both electrically and physically.