Mobile communication terminal

• US 7,158,820 B2
• Filed: 09/24/2004
• Issued: 01/02/2007
• Est. Priority Date: 01/13/2004
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Amano, Takashi, Suzuki, Hiromichi
• Primary Examiner(s): Tran; CongVan
• Application Number:
  US10/948,876
• Publication Number:
  US 20050153755A1
• Time in Patent Office: 830 Days
• Field of Search: 455/562.1, 455/575.1, 455/575.7, 455/274, 455/121, 455/129, 455/269
• US Class Current: 455/575.7
• CPC Class Codes: H01Q 1/243 with built-in antennas
• 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 5/371 Branching current paths
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic 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

Abstract

A mobile communication terminal of a portable telephone is housed in a casing having a first surface. A receiver section of the portable telephone capable of generating a voice is arranged on the first surface. A two-wavelength loop antenna arranged on a plane substantially parallel to the first plane and formed of a looped line having a right section and a left section that are in symmetry with respect to an imaginary vertical symmetric line is housed in the casing. A power supply point for supplying an electric power to the loop antenna is arranged in the vicinity of the intersection between the symmetric line and the looped line.

Claims

1. A mobile communication terminal, comprising:

a casing having a first surface;

a receiver section which is configured to reproduce a voice, and which is arranged at the first surface of the casing;

a two-wavelength loop antenna housed in the casing and arranged in a plane that is substantially parallel to the first surface of the casing; and

a power supply point to supply electric power to the loop antenna;

wherein the two-wavelength loop antenna comprises a looped line that is divided by an imaginary line of symmetry into first and second portions that are arranged substantially in symmetry with respect to the imaginary line of symmetry and which are connected to each other at first and second intersections arranged on the imaginary line of symmetry;

wherein each of the first and second portions comprises;

a first line which is connected to the first intersection and which has a length of substantially ¼

of a wavelength of an electrical wave having a predetermined frequency;

a second line which is connected to the first line and which has a length of substantially ½

of the wavelength of the electrical wave, wherein the second line is shaped in a folded form so as to cancel current vectors produced in the second line; and

a third line which is connected between the second line and the second intersection and which has a length of substantially ¼

of the wavelength of the electrical wave; and

wherein the power supply point is arranged in a vicinity of the first intersection.