ANTENNA DEVICE AND PORTABLE WIRELESS TERMINAL EQUIPPED WITH THE SAME

• US 20130057448A1
• Filed: 05/16/2011
• Published: 03/07/2013
• Est. Priority Date: 05/17/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Satou, Hiroshi, Hirobe, Takanori, Koyanagi, Yoshio, Nishikido, Tomoaki
• Granted Patent: US 9,105,975 B2
• Time in Patent Office: Days
• US Class Current: 343/853
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 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 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A second slit 117 and a fourth slit 119 provided in a first antenna element 150 and a first slit 116 and a third slit 118 provided in a second antenna element 151 are adjusted such that the mutual coupling between the first antenna element 150 and the second antenna element 151 in the desired frequency band is canceled, and reduces degradation in coupling between antenna elements without connecting the antenna elements through components and the like. With such a configuration, it is possible to achieve high-efficiency loosely coupled MIMO array antennas operating in the same frequency band in a portable wireless terminal.

Claims

1. An antenna device comprising:

a casing;

a circuit board that is provided in the casing and has a ground pattern;

a first antenna element that includes a first conductor plate which is disposed in and near the casing and is conductive and substantially rectangular, a second conductor plate which shares one side of the first conductor plate in a widthwise direction thereof, is disposed on the first conductor plate at approximately 90 degrees, and is substantially rectangular, and a third conductor plate which shares the other side in the widthwise direction opposed to the one side of the second conductor plate shared with the first conductor plate, is disposed at approximately 90 degrees so as to be opposed to the first conductor plate, and is substantially rectangular; and

a second antenna element that includes a fourth conductor plate which is disposed in and near the casing and is conductive and substantially rectangular, a fifth conductor plate which shares one side of the fourth conductor plate in a widthwise direction thereof, is disposed on the fourth conductor plate at approximately 90 degrees, and is substantially rectangular, and a sixth conductor plate which shares the other side in the widthwise direction opposed to the one side of the fifth conductor plate shared with the fourth conductor plate, is disposed at approximately 90 degrees so as to be opposed to the fourth conductor plate, and is substantially rectangular,

wherein at least one slit with a predetermined length is provided in at least one of the first conductor plate, the second conductor plate, or the third conductor plate of the first antenna element,

wherein at least one slit with a predetermined length is provided in at least one of the fourth conductor plate, the fifth conductor plate, or the sixth conductor plate of the second antenna element,

wherein the first antenna element and the second antenna element are disposed to be close to each other substantially in parallel with each other at a predetermined distance away from the ground pattern on the circuit board, and are electrically connected to a first power supply section and a second power supply section, which are disposed on the circuit board, at both ends of one side of the circuit board, and

wherein a position and a length of the slit are adjusted such that mutual coupling between the first antenna element and the second antenna element in a first frequency band is canceled.

2. The antenna device according to claim 1, wherein the first antenna element is electrically connected to the first power supply section through a first impedance matching circuit, and the second antenna element is electrically connected to the second power supply section through a second impedance matching circuit.

3. The antenna device according to claim 2, wherein the antenna device is a MIMO antenna device.

4. A portable wireless terminal comprising the antenna device according to claim 1.