ELECTRONIC DEVICE FOR COMMUNICATION

• US 20160064823A1
• Filed: 08/27/2015
• Published: 03/03/2016
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Sasaki, Hideki, Tsukuda, Tatsuaki
• Granted Patent: US 10,044,195 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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, comprising:

an antenna that forms an electromagnetic field;

a communication circuit coupled to the antenna;

a metallic part, at least a part of which includes 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 wiring width of the antenna.

2. The electronic device for communication according to claim 1,

wherein the antenna is a loop antenna.

3. The electronic device for communication according to claim 2,

wherein the loop antenna is formed by a wiring over a resin substrate.

4. The electronic device for communication according to claim 2,

wherein the metallic part is a battery pack.

5. The electronic device for communication according to claim 2,

wherein the metallic part is a substrate having a wiring formed therein.

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 has 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 a 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, comprising:

an antenna that forms an electromagnetic field;

a communication circuit coupled to the antenna;

a metallic part, at least a part of which includes a metal member; and

a magnetic sheet arranged between the antenna and the metallic part, the size of which 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.

11. The electronic device for communication according to claim 10,

wherein the antenna is a loop antenna.

12. The electronic device for communication according to claim 11,

wherein the loop antenna is formed by a wiring over a resin substrate.

13. The electronic device for communication according to claim 11,

wherein the metallic part is a battery pack.

14. The electronic device for communication according to claim 11,

wherein the metallic part is a substrate having a wiring formed therein.

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 has 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 a 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.