Electronic device for communication

• US 10,044,195 B2
• Filed: 08/27/2015
• Issued: 08/07/2018
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Tsukuda, Tatsuaki, Sasaki, Hideki
• Primary Examiner(s): Dinh, Trinh
• Application Number:
  US14/838,147
• Publication Number:
  US 20160064823A1
• Time in Patent Office: 1,076 Days
• Field of Search: None
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• 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: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

Abstract

To achieve a reduction of noise in a wireless system of an electronic device for communication. The electronic device for communication includes: a bottom lid; a loop antenna that forms an electromagnetic field; a communication circuit coupled to the loop antenna; a battery pack that is a metallic part; a magnetic sheet arranged between the loop antenna and the metallic part, the magnetic sheet including a protruding portion that protrudes outside an outer peripheral portion of the loop antenna; a wiring substrate arranged over the battery pack and having an IC and the like mounted thereon; and a lid with a display arranged over the wiring substrate, in which, with the outer peripheral portion of the loop antenna as a base point, a protruding amount from the base point of the protruding portion of the magnetic sheet is twice or more a wiring width of the loop antenna.

Claims

1. An electronic device for communication, the electronic device comprising:

an antenna that forms an electromagnetic field;

a communication circuit coupled to the antenna;

a metallic part, at least a part of the metallic part including a metal member, and

a magnetic sheet arranged between the antenna and the metallic part, the magnetic sheet including a protruding portion that protrudes outside an outer peripheral portion of the antenna,

wherein, with the outer peripheral portion of the antenna as a base point, a protruding amount from the base point of the protruding portion of the magnetic sheet is twice or more a width of a wiring of the antenna,

wherein the metallic part includes a rectifier circuit that rectifies a signal obtained via the antenna, and

wherein a material of a side of the magnetic sheet that faces the antenna has a magnetic loss less than a material of a side of the magnetic sheet that faces the metallic part.

2. The electronic device for communication according to claim 1, wherein the antenna comprises a loop antenna.

3. The electronic device for communication according to claim 2, wherein the loop antenna is formed by the wiring in a resin substrate.

4. The electronic device for communication according to claim 2, further comprising a battery pack disposed on the magnetic sheet.

5. The electronic device for communication according to claim 2, wherein the metallic part comprises a substrate including a wiring formed in the substrate.

6. The electronic device for communication according to claim 5, wherein a part of the magnetic sheet is arranged in a position inside a loop shape of the loop antenna.

7. The electronic device for communication according to claim 6, wherein the magnetic sheet includes a two-layer structure.

8. The electronic device for communication according to claim 6, wherein a through-hole penetrating from a front surface to a back surface is formed in the magnetic sheet.

9. The electronic device for communication according to claim 7, wherein the rectifier circuit is formed in the substrate,

wherein the magnetic sheet includes a first layer part arranged on a side of the loop antenna and a second layer part arranged on a side of the substrate,

wherein a magnetic loss of the first layer part is smaller than a magnetic loss of the second layer part,

wherein a size of the first layer part in a plan view is larger than a size of the antenna, and

wherein the second layer part is arranged corresponding to a position of the rectifier circuit.

10. An electronic device for communication, the electronic device comprising:

an antenna that forms an electromagnetic field;

a communication circuit coupled to the antenna;

a metallic part, at least a part of the metallic part including a metal member; and

a magnetic sheet arranged between the antenna and the metallic part, a size of the magnetic sheet in a plan view is larger than a size of the antenna,

wherein a thickness of the magnetic sheet is 100 μ

m or more and 650 μ

m or less,

wherein the metallic part includes a rectifier circuit that rectifies a signal obtained via the antenna, and

wherein a material of a side of the magnetic sheet that faces the antenna has a magnetic loss less than a material of a side of the magnetic sheet that faces the metallic part.

11. The electronic device for communication according to claim 10, wherein the antenna comprises a loop antenna.

12. The electronic device for communication according to claim 11, wherein the loop antenna is formed by a wiring in a resin substrate.

13. The electronic device for communication according to claim 11, further comprising a battery pack disposed on the magnetic sheet.

14. The electronic device for communication according to claim 11, wherein the metallic part comprises a substrate including a wiring formed in the substrate.

15. The electronic device for communication according to claim 14, wherein a part of the magnetic sheet is arranged in a position inside a loop shape of the loop antenna.

16. The electronic device for communication according to claim 15, wherein the magnetic sheet includes a two-layer structure.

17. The electronic device for communication according to claim 15, wherein a through-hole penetrating from a front surface to a back surface is formed in the magnetic sheet.

18. The electronic device for communication according to claim 16, wherein the rectifier circuit is formed in the substrate,

wherein the magnetic sheet includes a first layer part arranged on a side of the loop antenna and a second layer part arranged on a side of the substrate,

wherein a magnetic loss of the first layer part is smaller than a magnetic loss of the second layer part,

wherein a size of the first layer part in the plan view is larger than a size of the antenna, and

wherein the second layer part is arranged corresponding to a position of the rectifier circuit.

19. An electronic device for communication, the electronic device comprising:

an antenna that forms an electromagnetic field;

a communication circuit coupled to the antenna;

a metallic part, at least a part of the metallic part including a metal member; and

a magnetic sheet arranged between the antenna and the metallic part, the magnetic sheet including a protruding portion that protrudes outside an outer peripheral portion of the antenna,

wherein, with the outer peripheral portion of the antenna as a base point, a protruding amount from the base point of the protruding portion of the magnetic sheet is twice or more a width of a wiring of the antenna,

wherein the metallic part includes a rectifier circuit that rectifies a signal obtained via the antenna,

wherein magnetic losses of opposing sides of the magnetic sheet that face the antenna and the metallic part, respectively, are different,

wherein the rectifier circuit is formed in a substrate of the metallic part,

wherein the magnetic sheet includes a first layer part arranged on a side of the antenna and a second layer part arranged on a side of the substrate, and

wherein a magnetic loss of the first layer part is less than a magnetic loss of the second layer part.

20. The electronic device for communication according to claim 19, wherein a size of the first layer part in a plan view is larger than a size of the antenna, and

wherein the second layer part is arranged corresponding to a position of the rectifier circuit.