Multi-band monopole antennas for mobile communications devices

• US 20090033561A1
• Filed: 08/13/2008
• Published: 02/05/2009
• Est. Priority Date: 12/22/2002
• Status: Active Grant

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: Baliarda, Carles Puente, Pros, Jaume Anguera
• Granted Patent: US 8,456,365 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• 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 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

Antennas for use in mobile communication devices are disclosed. The antennas disclosed can include a substrate with a base, a top, a front side and a back side; a first conductor can be located on the first side of the antenna substrate; and a second conductor can be located on the second side of the antenna substrate. The conductors can have single or multiple branches. If a conductor is a single branch it can, for example, be a spiral conductor or a conducting plate. If a conductor has multiple branches, each branch can be set up to receive a different frequency band. A conductor with multiple branches can have a linear branch and a space-filling or grid dimension branch. A conducting plate can act as a parasitic reflector plane to tune or partially tune the resonant frequency of another conductor. The first and second conductors can be electrically connected.

Claims

1. An antenna for use in a mobile communication device, comprising:

an antenna substrate with a base, a top, a front side and a back side;

a first conductor located on the front side of the antenna substrate, said first conductor comprising a dual branched antenna with a space-filling or grid dimension branch and a linear branch; and

a second conductor located on the back side of the antenna substrate, said second conductor comprising a conducting plate.

2. The antenna of claim 1, wherein the first conductor and the second conductor are electrically connected.

3. The antenna of claim 2, wherein the first conductor and the second conductor are electrically connected through one or more holes cut in the antenna substrate.

4. The antenna of claim 1, wherein the first conductor is connected to a feeding port used to form an electrical connection between the antenna and a mobile communication device.

5. The antenna of claim 1, wherein the space-filling or grid dimension branch of the first conductor receives frequencies in the GSM900 band.

6. The antenna of claim 1, wherein the linear branch of the second conductor receives frequencies in the GSM1800 band.

7. The antenna of claim 1, wherein the second conductor acts as a parasitic plane reflector.

8. The antenna of claim 6, wherein the second conductor is positioned behind the space-filling or grid dimension branch of the dual branched conductor.

9. The antenna of claim 6, wherein the second conductor is smaller than the space-filling or grid dimension branch of the dual branched antenna and the second conductor is positioned behind a portion of the dual branched antenna.

10. The antenna of claim 1, wherein the second conductor has a non-rectangular shape.

11. The antenna of claim 1, wherein one or more curves of the space-filling or grid dimension branch of the dual branched antenna are replaced by a solid conductor portion.

12. The antenna of claim 1, wherein the linear branch of the first conductor is electrically connected to the space-filling or grid dimension branch near a proximal end of the space-filling or grid dimension branch, said proximal end of the space-filling or grid dimension branch located near the base of the antenna substrate.

13. The antenna of claim 6, wherein the linear branch of the first conductor is electrically connected to the space-filling or grid dimension branch at a distal end of the space-filling or grid dimension branch.

14. A housing for use with a mobile communication device containing the antenna of claim 6.

15. A multi-band monopole antenna for external use in a mobile communication device, comprising:

an antenna substrate with a base, a top, a front side and a back side;

a first conductor located on the front side of the antenna substrate, said first conductor comprising a dual branched antenna with a space-filling or grid dimension branch for receiving frequencies in the GSM900 band and a linear branch for receiving frequencies in the GSM1800 band; and

a second conductor located on the back side of the antenna substrate, said second conductor comprising a conducting plate that is positioned behind the space-filling or grid dimension branch of the dual branched antenna, wherein the first conductor and the second conductor are electrically connected at the top of the antenna substrate through holes in the antenna substrate.