Couple-fed multi-band loop antenna

• US 20090273530A1
• Filed: 09/29/2008
• Published: 11/05/2009
• Est. Priority Date: 05/05/2008
• Status: Active Grant

• Current Assignee: Acer, Inc.
• Original Assignee: Acer, Inc.
• Inventors: Chi, Yun-Wen, Wong, Kin-Lu
• Granted Patent: US 7,978,141 B2
• Time in Patent Office: Days
• US Class Current: 343/741
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/357 using a single feed point
• 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: 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 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0457 electromagnetically coupled to the feed line

Abstract

The present invention is related to a coupled-fed multi-band loop antenna. The antenna comprises a dielectric substrate, a ground plane located on the dielectric substrate and has a grounding point, a radiating portion which comprise a supporter, a coupling trip and a loop strip, and a matching circuit. The coupling strip and loop strip are both located on the supporter, with the coupling strip surrounded by the loop strip. The length of loop strip is about 0.25 wavelength of the antenna'"'"'s first resonant mode. The loop strip has a first end paralleling with the coupling loop, a second end and a shorting point near the second end and electrically connected to the grounding point on the ground plane. The matching circuit is on the dielectric substrate. One terminal of the matching circuit is connected to the coupling strip, and the other is connected to a signal source.

Claims

1. A coupled-fed multi-band loop antenna, comprising:

a dielectric substrate;

a ground plane located on the dielectric substrate, and having a grounding point;

a radiating portion, comprising;

a supporting substrate;

a coupling metal strip located on the supporting substrate; and

a radiating loop-shaped metal strip located on the supporting substrate and enclosing the coupling metal strip, wherein the length of the radiating loop-shaped metal strip is substantially ¼

wavelength of the lowest resonant frequency of the antenna, and the radiating loop-shaped metal strip has a first end, a second end and a shorting point, and the first end is roughly parallel with the coupling metal strip, and the shorting point is located near the second end and electrically connected to the grounding point of the ground plane; and

a matching component group located on the dielectric substrate, and one terminal of the matching component group electrically connected to the coupling metal strip of the radiating portion, and the other terminal of the matching component group connected to a signal source.

2. The antenna of claim 1, wherein the dielectric substrate is a system circuit board of a mobile communication device.

3. The antenna of claim 1, wherein the ground plane is a system ground plane of a mobile communication device.

4. The antenna of claim 1, wherein the ground plane is formed on the dielectric substrate by printing or etching.

5. The antenna of claim 1, wherein the material of the supporting substrate is selected from the group consisting of the dielectric substrate, plastic and ceramics.

6. The antenna of claim 1, wherein the coupling metal strip is substantially straight, or L-shaped or T-shaped.

7. The antenna of claim 1, wherein the coupling metal strip has at least two arms.

8. The antenna of claim 1, wherein the matching component group is a circuit including at least one inductive component.