Multi-band antenna

• US 9,570,803 B2
• Filed: 02/17/2016
• Issued: 02/14/2017
• Est. Priority Date: 08/08/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shimura, Hajime
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US15/045,915
• Publication Number:
  US 20160164176A1
• Time in Patent Office: 363 Days
• Field of Search: 343/702, 343/700.MS, 343/846
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/12 Supports; Mounting means
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/10 Resonant antennas
• CPC Class Codes: H01Q 5/307 Individual or coupled radiating elements, each element being fed in an unspecified way
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 9/04 Resonant antennas
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/065 Microstrip dipole antennas patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

An antenna which operates in a plurality of frequency bands includes a feeding point, a first conductor which is connected to the feeding point, and at least two second conductors which are branched from the first conductor, have a linear shape, and include open ends as ends on a side opposite to the first conductor. The open ends of the two second conductors face in almost the same direction substantially parallel to a side closest to the feeding point out of the sides of an antenna region. The two second conductors include a part at which the distance between the two conductors at a portion parallel to the side is a first distance, and another part at which the distance is a second distance shorter than the first distance, and are electromagnetically coupled at, at least the other part.

Claims

1. A multiband antenna that operates in a plurality of frequency bands, comprising:

a first conductor that has a linear shape; and

a second conductor that has a linear shape;

wherein the first conductor and the second conductor both comprise a first part and a second part, wherein a distance between the first part of the first conductor and the first part of the second conductor is a first distance and a distance between the second part of the first conductor and the second part of the second conductor is a second distance shorter than the first distance,

wherein the second part of the first conductor is substantially parallel to the second part of the second conductor, and a direction of the second part of the first conductor toward an open end of the first conductor is substantially the same as a direction of the second part of the second conductor toward an open end of the second conductor,

wherein the first conductor and the second conductor are electromagnetically coupled to each other in at least the second part, and

wherein at least the second part of the first conductor is arranged on a plane different from another plane whereon the second part of the second conductor is arranged, and each of operating frequencies of the first conductor and the second conductor is shifted, by the first conductor and the second conductor being electromagnetically coupled, to be lower than each of operation frequencies when the first conductor and the second conductor are not electromagnetically coupled.

2. The multiband antenna according to claim 1, wherein the first conductor has a length different from the second conductor.

3. The multiband antenna according to claim 2, wherein the first conductor operates mainly in a 2.4 GHz frequency band and the second conductor operates mainly in a 5 GHz frequency band.

4. The multiband antenna according to claim 1, wherein at least one of the first conductor and the second conductor has a meander line shape.

5. The multiband antenna according to claim 1, wherein the multiband antenna is arranged on a substrate.

6. The multiband antenna according to claim 5, wherein the second part of the first conductor is arranged on a front surface of the substrate and the second part of the second conductor is arranged on a back surface of the substrate.

7. The multiband antenna according to claim 5, wherein the substrate is a dielectric substrate.

8. The multiband antenna according to claim 1, further comprising a dielectric substance which has a relative dielectric constant of larger than 1, and is arranged and added in contact with or at a predetermined distance from the multiband antenna.

9. The multiband antenna according to claim 8, wherein the dielectric substance includes a dielectric sheet, and is adhered to the entire multiband antenna.

10. The multiband antenna according to claim 8, wherein the dielectric substance is arranged and added in contact with or at a predetermined distance from only one of the first conductor and the second conductor for which an operating frequency is to be shifted to be low.

11. The multiband antenna according to claim 1, wherein the second part of the first conductor and the second part of the second conductor are arranged substantially in parallel with one of sides of an area where the multiband antenna is formed.