Multi-band antenna for GSM, UMTS, and WiFi applications

• US 20070268190A1
• Filed: 05/17/2006
• Published: 11/22/2007
• Est. Priority Date: 05/17/2006
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: Huynh, Minh-Chau
• Granted Patent: US 7,432,860 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 5/385 Two or more parasitic elements
• CPC Class Codes: H01Q 5/392 the parasitic elements having dual-band or multi-band characteristics
• CPC Class Codes: H01Q 9/0414 in a stacked or folded configuration

Abstract

The multi-band antenna described herein includes multiple antenna elements that collectively resonate in multiple different frequency bands. One exemplary antenna includes first and second vertically spaced antenna elements that connect to a ground plane. A feed antenna element positioned between the first and second antenna elements connects to an antenna feed. The electromagnetic coupling produced by the arrangement of these antenna elements produces multiple resonant frequencies, and therefore, defines multiple operating frequency bands of the multi-band antenna.

Claims

1. A multi-band antenna comprising:

first and second vertically spaced antenna elements connected to a ground plane; and

a feed antenna element connected to an antenna feed and disposed between the first and second antenna elements, said feed antenna element comprising first and second branches arranged to electro-magnetically couple with the first and second antenna elements to define multiple operating frequency bands of the multi-band antenna.

2. The multi-band antenna of claim 1 wherein the second antenna element overlaps distal ends of the first and second branches of the feed antenna element.

3. The multi-band antenna of claim 2 wherein the distal end of at least one of the first and second branches overlaps a portion of the first antenna element.

4. The multi-band antenna of claim 1 wherein the first branch of the feed antenna element is generally S-shaped, and wherein the second branch of the feed antenna element is generally L-shaped.

5. The multi-band antenna of claim 1 wherein the first and second branches of the feed antenna element connect at a common end, and wherein the common end electrically connects to the antenna feed.

6. The multi-band antenna of claim 1 wherein the feed antenna element is disposed mid-way between the first and second antenna elements.

7. The multi-band antenna of claim 1 wherein the first antenna element is generally U-shaped, and wherein a first end of the generally U-shaped first antenna element connects to the ground plane via a ground connector.

8. The multi-band antenna of claim 7 wherein the second antenna element is generally I-shaped, and wherein the multi-band antenna further comprises a conducting strip that electrically connects one end of the generally I-shaped second antenna element to a middle section of the generally unshaped first antenna element.

9. The multi-band antenna of claim 8 wherein the ground connector and the conducting strip connect to opposing corners of the generally U-shaped first antenna element.

10. The multi-band antenna of claim 1 wherein the multi-band antenna covers first, second, and third frequency bands.

11. The multi-band antenna of claim 10 wherein a Global System for Mobile communications standard defines the first frequency band, a Universal Mobile Telecommunication System standard defines the second frequency band, and an Unlicensed National Information Infrastructure standard defines the third frequency band.

12. The multi-band antenna of claim 1 wherein a path length of the first antenna element and a path length of the second antenna element have approximately the same length.

13. The multi-band antenna of claim 12 wherein a length of the ground plane is greater than or equal to at least one of the path lengths of the first and second antenna elements.

14. The multi-band antenna of claim 12 wherein a length of the ground plane is greater than or equal to ¼

of a wavelength corresponding to an operating frequency of the multi-band antenna.

15. A mobile communication device comprising:

a multi-band antenna comprising;

first and second vertically spaced antenna elements connected to a ground plane; and

a feed antenna element connected to an antenna feed and disposed between the first and second antenna elements, said feed antenna element comprising first and second branches arranged to electro-magnetically couple with the first and second antenna elements; and

a transceiver system configured to transmit and receive wireless communication signals via the multi-band antenna.

16. The mobile communication device of claim 15 wherein the second antenna element overlaps distal ends of the first and second branches of the feed antenna element.

17. The mobile communication device of claim 15 wherein the multi-band antenna covers first, second, and third frequency bands.

18. The mobile communication device of claim 17 wherein a Global System for Mobile communications standard defines the first frequency band, a Universal Mobile Telecommunication System standard defines the second frequency band, and an Unlicensed National Information Infrastructure standard defines the third frequency band.

19. A method of constructing a multi-band antenna comprising:

connecting first and second vertically spaced antenna elements to a ground plane; and

disposing a feed antenna element connected to an antenna feed between the first and second antenna elements, said feed antenna element comprising first and second branches arranged to electro-magnetically couple to the first and second antenna elements.

20. The method of claim 19 further comprising overlapping distal ends of the feed antenna element with at least one portion of the second antenna element.

21. The method of claim 19 further comprising generally arranging the first branch of the feed antenna element in an S-shape and generally arranging the second branch of the feed antenna element in an L-shape.

22. The method of claim 19 further comprising:

connecting the first and second branches at a common end; and

electrically connecting the common end to the antenna feed.

23. The method of claim 19 further comprising:

generally arranging the first antenna element in a U-shape; and

connecting a first end of the generally U-shaped first antenna element to the ground plane via a ground connection.

24. The method of claim 23 further comprising:

generally arranging the second antenna element in an I-shape; and

electrically connecting one end of the generally I-shaped second antenna element to a middle section of the generally U-shaped first antenna element using a conducting strip vertically disposed between the first and second antenna elements.

25. The method of claim 19 wherein the multi-band antenna covers first, second, and third frequency bands.

26. The method of claim 25 wherein a Global System for Mobile communications standard defines the first frequency band, a Universal Mobile Telecommunication System standard defines the second frequency band, and an Unlicensed National Information Infrastructure standard defines the third frequency band.