Mobile phone having reduced specific absorption rate (SAR) using an antenna housed to ensure enhanced antenna gain

• US 7,099,631 B2
• Filed: 03/04/2003
• Issued: 08/29/2006
• Est. Priority Date: 09/04/2000
• Status: Expired due to Term

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Yun, Je Hoon, Park, Hyun Ho, Kwon, Jong Hwa, Choi, Jae Ick, Lee, Tae Yune
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Tran, Chuc
• Application Number:
  US10/380,000
• Publication Number:
  US 20040023682A1
• Time in Patent Office: 1,274 Days
• Field of Search: 343/702, 343/718, 343/841, 343/899, 343/700.MS, 343/895, 343/906, 455/550.1, 455/575.1, 455/90, 455/272, 455/562.1, 455/575.7
• US Class Current: 455/90.1
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• CPC Class Codes: H01Q 17/001 for modifying the directional characteristic of an aerial
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Abstract

The present invention relates to a structure of an antenna and its shielding structure for a mobile phone which may significantly reduce the hazardous electromagnetic wave transmitted to the user'"'"'s body. The present invention arranges a monopole antenna inside of the mobile phone housing, and installs an electromagnetic wave absorber between the antenna and the circuit board. The electromagnetic wave absorber can absorb the electromagnetic wave reflected form conductive plate constituting the circuit board. Thus, the adverse effect of the reflected electromagnetic wave to the performance of antenna is prevented and the amount of the electromagnetic wave to which the users is exposed can be significantly reduced as well.

Claims

1. A mobile phone comprising:

at least one circuit board being used to accommodate various electronic devices performing various functions such as transmission and reception of electromagnetic waves;

a housing having an inside in which said circuit board is contained; and

an antenna arranged in the inside of the housing at a position adjoining a rear wall of the housing with a distance from a nearest circuit board, and being used to allow electronic devices installed on said circuit board to transmit and receive the electromagnetic waves; and

wherein an electromagnetic wave absorber is arranged between said antenna and the nearest circuit board to the antenna while covering the length of the antenna except a lower part thereof,

wherein the electromagnetic wave absorber encloses a circumference of the antenna with a degree greater than 180°

through having a first wall attached to the nearest circuit board and a second wall extending from at least one side of the first wall toward the rear wall of the housing.

2. The mobile phone of claim 1, wherein the housing comprises a type selected from a group consisting of a bar-type, a flip-type, and a folder-type.

3. The mobile phone of claim 1, further comprising at least one conductive plate arranged between said circuit board and said electromagnetic wave absorber.

4. The mobile phone of claim 1, wherein said electromagnetic wave absorber has a rectangular-shape when viewed from the front side of the mobile phone, and the cross-section of said electromagnetic wave absorber taken along a lateral direction of the mobile phone protrudes toward a front-side of the mobile phone.

5. The mobile phone of claim 1, wherein said electromagnetic wave absorber is open with a range of 90°

to less than 180°

around the center of the antenna, and its lateral cross-section has a shape selected from a group consisting of a circle, a triangle, a quadrangle, a polygon, and an ellipse.

6. The mobile phone of claim 2, wherein said housing comprises a folder-type housing composed of a main housing member and a sub housing member, and said electromagnetic wave absorber and the antenna are installed within one of the main housing member or within the sub housing member.

7. The mobile phone of claim 1, wherein said electromagnetic wave absorber and the antenna are arranged adjacent to an upper wall of the housing.

8. The mobile phone of claim 1, wherein said electromagnetic wave absorber and the antenna are arranged adjacent to a lower wall of the housing.

9. The mobile phone of claim 1, wherein said antenna comprises a monopole antenna.

10. The mobile phone of claim 9, wherein said antenna has a lateral cross-section of a shape selected from a group consisting of a circle, a triangle, a quadrangle, a polygon, and an ellipse.

11. The mobile phone of claim 9, wherein said antenna has a shape selected from a group consisting of a helical-shape, a conical-shape, and a spherical-shape.

12. The mobile phone of claim 1, wherein said electromagnetic wave absorber has a shape selected from a group consisting of a circle-shape, a triangle-shape, a quadrangle-shape, a polygon-shape, and an ellipse-shape when viewed from a front side of the mobile phone.