Shielded coil for inductive wireless applications

• US 20070115198A1
• Filed: 11/17/2006
• Published: 05/24/2007
• Est. Priority Date: 11/17/2005
• Status: Active Grant

• Current Assignee: Oticon A/S (William Demant Fonden)
• Original Assignee: Oticon A/S (William Demant Fonden)
• Inventors: Nielsen, Christian, Essabar, Mohamad, Rasmussen, Frank, Ollgaard, Mogens, Mullenborg, Matthias
• Granted Patent: US 7,592,964 B2
• Time in Patent Office: Days
• US Class Current: 343/788
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/44 using equipment having another main function to serve additionally as an antenna , e.g. means for giving an antenna an aesthetic aspectH01Q1/27 - H01Q1/34 take precedence
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• 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 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H04R 2225/51 Aspects of antennas or their circuitry in or for hearing aids

Abstract

The present invention relates to a surface mounted coil (200) for wireless communication. The coil (200) comprises a wire (202) wounded about a core (204) thereby establishing a plurality of windings and having its ends terminated on mounting sections (208) at each end of the core (204). The coil (200) further comprises a shielding layer (212, 300) wound about a central part of the core (204) thereby covering said windings. The shielding layer (212, 300) comprises a shielding pattern and a contact section (214) for connecting to a ground level and to the shielding pattern.

Claims

1. A surface mounted coil for wireless communication, and comprising a wire wounded about a core thereby establishing a plurality of windings and having its ends connected to mounting sections at each end of said core, and wherein said surface mounted coil further comprising a shielding layer provided between mounting sections thereby covering said windings, said shielding layer comprising a shielding pattern and a contact section for connecting to a reference level and to said shielding pattern.

2. A coil according to claim 1, wherein said core comprises a soft-magnetic material, such as ferrite.

3. A coil according to any of claims 1 or 2, wherein said shielding layer comprises a non-conductive layer, such as a tape, a flexible substrate, a printed circuit board, a printed wired board, or any combination thereof.

4. A coil according to claim 1, wherein said shielding pattern comprises one or more conductive tracks connected single ended to said contact section.

5. A coil according to claim 1, wherein said shielding pattern has a comb shape, snake shape, or any combination thereof.

6. A coil according to claim 1, wherein said shielding pattern comprises a series of conductive tongs extending from a longitudinal conductive axis.

7. A coil according to claim 6, wherein said conductive tongs define a width varying along said longitudinal conductive axis.

8. A coil according to any of claims 6 to 7, wherein said conductive tongs define a width varying along a direction perpendicular to said longitudinal conductive axis.

9. A coil according to claim 6, wherein said series of conductive tongs extends from either side of said longitudinal conductive path, which is positioned between said mounting feet with the series of conductive tracks folded circumferentially about said plurality of windings.

10. A coil according to claim 1, wherein said shielding pattern comprises a second antenna adapted to operate at a frequency range different from operating frequency of the coil.

11. A coil according to claim 10, wherein said coil is adapted to communicate wirelessly at radiofrequencies within a first frequency range while said second antenna is adapted to communicate at radiofrequencies within a second frequency range.

12. A coil according to claim 11, wherein said first frequency range is shifted downwards relative to said second frequency range.

13. A coil according to claim 11, wherein said first frequency range is adapted for operation in accordance with a proprietary protocol while said second frequency range is adapted for operation in accordance with a non-proprietary protocol, such as bluetooth.

14. A coil according to claim 1, wherein said coil has an axial length between 1 to 10 mm.

15. A hearing aid comprising a surface mounted coil for inductive wireless communication according to any of claim 1.

17. A shielding layer according to claim 16, wherein said shielding layer is adapted to be applied to said coil according to claim 1 or in said hearing aid according to claim 15.

18. A method for manufacturing a coil according to claim 1 and comprising:

winding a wire about a core thereby establishing a plurality of windings and connecting its ends to mounting sections at each end of said core, adding a shielding layer comprising a non-conductive layer and a conductive pattern between said mounting sections, and connecting a contact section to a reference level and to said shielding pattern.

19. A method according to claim 18, wherein said non-conductive layer is deposited on top of said coil windings by a fluidized bed process, by a chemical vapour deposition process, by dip coating process, by spray coating process, by electrochemical deposition or a printable process.

20. A method according to claim 18, wherein said shielding pattern is positioned on non-conductive layer such as tape, a flexible substrate, a printed circuit board, a printed wired board, or any combination thereof, folded circumferentially about said plurality of windings.

21. A method according to claim 18, wherein said shielding pattern comprises a contact pad and conductive tracks established by a non-selective electrochemical deposition process followed by physical or chemical structuring, by selective electrochemical deposition process, by non-selective chemical or physical vapour deposition process followed by physical or chemical structuring, or in a printing process.

16. A shielding layer for shielding an antenna for inductive wireless communication and comprising a tape, a flexible substrate, a printed circuit board, a printed wired board, or any combination thereof and having a shielding pattern comprising one or more conductive tracks single ended connected to a contact section.