Near field communication

• US 8,212,735 B2
• Filed: 06/05/2009
• Issued: 07/03/2012
• Est. Priority Date: 06/05/2009
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Hyvonen, Lassi, Troelsen, Jens, Pinto, Alexandre
• Primary Examiner(s): Duong, Dieu H
• Application Number:
  US12/455,751
• Publication Number:
  US 20100309088A1
• Time in Patent Office: 1,124 Days
• Field of Search: 343/867, 343/853, 343/855, 343/751, 343/893, 343/725, 343/728, 343/702, 343/742, 343/744, 343/866
• US Class Current: 343/867
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• 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 5/26 using coils

Abstract

Apparatus including: an antenna configured for efficient far field communication at a first frequency; an inductive element including a plurality of series-connected coiled portions, including a first coiled portion and a second coiled portion, wherein the inductive element is configured to provide near field communication at a second frequency; and at least one reactive element parallel connected between the first coiled portion and the second coiled portion, wherein the at least one reactive element has a lower impedance at the first frequency than at the second frequency.

Claims

1. An apparatus comprising:

an antenna configured for efficient far field communication at a first frequency;

an inductive element comprising a plurality of series-connected coiled portions, including a first coiled portion and a second coiled portion, wherein the inductive element is configured to provide near field communication at a second frequency; and

at least one reactive element parallel connected between the first coiled portion and the second coiled portion, wherein the at least one reactive element has a lower impedance at the first frequency than at the second frequency,

wherein the inductive element and the at least one reactive element are configured to be co-located with the antenna without affecting performance of the antenna.

2. The apparatus as claimed in claim 1, wherein the inductive element spirals about a centre axis and wherein each of the coiled portions form spiraling loops having different separations from the centre axis.

3. The apparatus as claimed in claim 1, wherein the inductive element lies substantially within a two dimensional plane.

4. The apparatus as claimed in claim 1 wherein the first frequency is greater than the second frequency.

5. The apparatus as claimed in claim 1 wherein the at least one reactive element is predominantly capacitive.

6. The apparatus as claimed in claim 1 comprising a plurality of reactive elements connected in parallel between respective coiled portions of the inductive element and each having a lower impedance at the first frequency than at the second frequency.

7. The apparatus as claimed in claim 6 wherein the one or more reactive elements connected in parallel between respective coiled portions of the inductive element modify the resonant characteristics of the inductive element to reduce coupling between the antenna and the inductive element at operational frequencies of the antenna.

8. The apparatus as claimed in claim 1, wherein the inductive element has a first port and a second port and a first additional reactive element is series connected to the first port, wherein the first additional reactive element has a higher electrical impedance at the first frequency than at the second frequency.

9. The apparatus as claimed in claim 8, wherein a second additional reactive element is series connected to the output port, wherein the second additional reactive element has a higher electrical impedance at the first frequency than at the second frequency.

10. The apparatus as claimed in claim 8, wherein at least the first additional reactive element is comprised within a matching network for the inductive element configured to enable the inductive element to provide more efficient near field communications at 13.56 MHz.

11. The apparatus as claimed in claim 1, wherein the inductive element has a first port and a second port and a filter positioned between the first port and the second port that enables simultaneous operation of the inductive element for near field communications and the antenna for radio communications.

12. The apparatus as claimed in claim 1, further comprising a ground plane for the antenna wherein the inductive element is positioned on an axis displaced from a first side of the antenna and the ground plane is positioned on an axis displaced from a second side of the antenna wherein the second side opposes the first side.

13. The apparatus as claimed in claim 1, configured as a module.

14. The apparatus as claimed in claim 1 configured as a communication device comprising a metallic housing, wherein the housing comprises a face presenting a metallic exterior and a non-metallic portion where metal is absent, and wherein the non-metallic portion is substantially aligned with both the antenna and the inductive element.

15. The apparatus as claimed in claim 14, wherein the housing has a substantially metal exterior except in the location of the non-metallic portion.

16. A portable electronic device comprising the apparatus of claim 1.

17. The apparatus as claimed in claim 1 configured as a portable electronic device comprising a plastic or nonmetallic housing.

18. A method comprising:

providing an inductive element comprising a plurality of series-connected coiled portions, including a first coiled portion and a second coiled portion; and

providing at least one reactive element in parallel connection between the first coiled portion and the second coiled portion of the inductive element, to produce a modified inductive element configured to provide near field communication at a second frequency when used in an apparatus configured for efficient far field radio communication at a first frequency different to the second frequency,

wherein the inductive element and the at least one reactive element are configured to be co-located with an antenna without affecting performance of the antenna.

19. An apparatus comprising:

an inductive element comprising a plurality of series-connected coiled portions, including a first coiled portion and a second coiled portion; and

at least one reactive element parallel connected between the first coiled portion and the second coiled portion,

wherein the inductive element and the at least one reactive element are configured to be co-located with an antenna without affecting performance of the antenna.

20. The apparatus as claimed in claim 19, wherein the inductive element is configured to provide near field communication at a first frequency of 13.56 MHz ±

7 kHz.

21. The apparatus as claimed in claim 19, wherein the at least one reactive element is configured to have a first impedance at a first frequency and a second impedance at a second frequency, wherein the second frequency is at least 100 times greater than the first frequency.

22. The apparatus as claimed in claim 19, wherein the inductive element is a coiled galvanic conductor.