Antenna Structure for a Wireless Device with a Ground Plane Shaped as a Loop

• US 20070252773A1
• Filed: 11/14/2005
• Published: 11/01/2007
• Est. Priority Date: 11/12/2004
• Status: Active Grant

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: Soler Castany, Jordi, Puente Baliarda, Carles
• Granted Patent: US 7,782,269 B2
• Time in Patent Office: Days
• US Class Current: 343/846
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• 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 1/48 Earthing means; Earth screens; Counterpoises
• 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 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

This invention refers to an antenna structure for a wireless device comprising a ground plane and an antenna element, wherein the ground plane has the shape of an open loop. The invention further refers to an antenna structure for a wireless device, such as a light switch or a wrist sensor or wristwatch, comprising an open loop ground plane having a first end portion and a second end portion, the open loop ground plane defining an opening between the first end portion and the second end portion; and an antenna component positioned within the opening defined between the first end portion and the second end portion and overlapping at least one of the first end portion or the second end portion. Further the invention refers to a corresponding wireless device and to a method for integrating such an antenna structure in a wireless device.

Claims

1. An antenna structure for a wireless device comprising:

a ground plane, and

an antenna element

wherein the ground plane has the shape of an open loop and the antenna element is located within an area defined by the open loop.

2. The antenna structure of claim 1, wherein the ground plane has at least one end portion, in the proximity of which the antenna element is located.

3. The antenna structure of claim 2, wherein the ground plane has a second end portion which is located in the proximity of the antenna element.

4. The antenna structure of claim 1, wherein the ground plane has at least two overlapping portions.

5. The antenna structure of claim 4, wherein the antenna element is located in proximity to the overlapping portions.

7. The antenna structure of claim 1, wherein the antenna element is substantially flat and is arranged substantially parallel to a portion of the ground plane which is located closest to the antenna element.

8. The antenna structure of claim 7, wherein the antenna element is provided such that in a projection of the antenna element onto the portion of the ground plane in the proximity of the antenna element in a direction orthogonal to the plane of the antenna element at least a portion of the antenna element is overlapping with the ground plane.

9. The antenna structure of claim 7, wherein the antenna element is provided such that in a projection of the antenna element onto the portion of the ground plane in the proximity of the antenna element in a direction orthogonal to the plane of the antenna element not less than 50% of the antenna element is overlapping with the ground plane.

10. The antenna element of claim 1, wherein the ground plane has a first end portion and a second end portion, the ground plane defining an opening between the first end portion and the second end portion and wherein the antenna element is positioned within that opening defined between the first end portion and the second end portion and overlaps with at least one end portion.

11. The antenna structure of claim 1, wherein the ground plane is provided on a circuit board.

12. The antenna structure of claim 11, wherein the ground plane is provided at least in part at a portion of the edge of the circuit board.

13. The antenna structure of claim 11, wherein the circuit board has at least one openings.

14. The antenna structure of claim 13, wherein at least one opening is at least partially surrounded by the ground plane.

15. The antenna structure of claim 11, wherein the ground plane and the antenna element are provided on at least one of the circuit board.

16. The antenna structure of claim 1, wherein the ground plane is provided as an at least partially rigid conductor.

17. The antenna structure of claim 1, wherein the ground plane is provided as an at least partially flexible conducting material.

18. The antenna structure of claim 1, wherein the antenna element is an antenna component.

19. The antenna structure of claim 1, wherein at least a portion of the ground plane a multilevel structure, a space filling curve, a grid dimension curve or a contour curve.

20. The antenna structure of claim 1, wherein at least a portion of the antenna element is a multilevel structure, space filling curve, a grid dimension curve or a contour curve.

21. The antenna structure of claim 1, wherein the antenna structure operates in at least one, two, three or more of the following cellular standards and communication systems:

Bluetooth, UltraWideBand (UWB), WiFi (IEEE802.11a,b,g), WiMAX (IEEE802.16), PMG, digital radio and television devices (DAB, DBTV), satellite systems such as GPS, Galileo, SDARS, GSM900, GSM1800, PCS1900, Korean PCS (KPCS), CDMA, WCDMA, UMTS, 3G, GSM850, ZigBee (868 and/or

     915).

22. The antenna structure of claim 1, wherein the antenna element is selected from the group comprising monopole, IFA, patch, microstrip antenna and PIFA.

23. The antenna structure of claim 1, wherein the antenna element comprises at least one contact point that connects the antenna element to the ground plane by direct electrical contact.

24. The antenna structure of claim 1, wherein the antenna element comprises at least one contact point which is used to feed the antenna.

31. The antenna structure of claim 1, wherein the antenna element is provided at a distance d from the ground plane and end portions thereof, wherein d may be from 2.0 to 0.05 times a largest extension of the antenna element.

32. The antenna structure of claim 1, wherein the antenna element is provided at a separation s from the ground plane and end portions thereof, wherein s may be from 2.0 to 0.05 times a largest extension of the antenna element.

33. The antenna structure of claim 7, wherein the antenna element is provided such that in a projection of the antenna element onto the portion of the ground plane in the proximity of the antenna element in a direction orthogonal to the plane of the antenna element not more than 50% of the antenna element is overlapping with the ground plane.

6. (canceled)

25. An antenna structure for a wireless device, comprising:

an open loop ground plane having a first end portion and a second end portion, the open loop ground plane defining an opening between the first end portion and the second end portion; and

an antenna component positioned within the opening defined between the first end portion and the second end portion and overlapping at least one of the first end portion or the second end portion.

34. Apparatus of claim 25, wherein the antenna structure is provided in a light switch.

35. Apparatus of claim 25, wherein the antenna structure is provided in a wrist sensor.

36. Apparatus of claim 25, wherein the antenna structure is provided in a wrist watch.

26. A wireless device comprising an antenna structure the antenna structure comprising:

a around plane, and

an antenna element

wherein the around plane has the shape of an open loop and the antenna element is located within an area defined by the open loop.

27. The wireless device of claim 26, wherein the wireless device is selected from the group of wireless devices comprising:

mini-PCI (e.g., notebook PC with integrated Wi-Fi module), compact flash wireless cards, wireless USB/UART dongles, PCMCIA wireless cards, headsets, pocket PC with integrated Wi-Fi, access points for hot-spots, wireless light switches, wireless wrist watches, wireless wrist sensors, a bracelet FM radio, an MP3 player, a radio frequency identification tag (RFID), a keyless remote entry system, a sensor such as an air pressure sensor in tires, radio controlled toys, a compact/wireless card, or any other wireless device.

28. A method to integrate an antenna structure in a wireless device comprising the steps of:

providing a ground plane to said wireless device;

shaping said ground plane as an open loop, so that it defines an opening;

and providing an antenna element to said wireless device.

29. The method as of claim 28, wherein said antenna element is provided within said opening.

30. The method of claim 28, wherein the method is carried out such that the antenna structure fits in the wireless device while said wireless device keeps its size reduced.

37. A wireless device comprising an antenna structure,

the antenna structure comprising:

an open loop ground plane having a first end portion and a second end portion, the open loop ground plane defining an opening between the first end portion and the second end portion; and

an antenna component positioned within the opening defined between the first end portion and the second end portion and overlapping at least one of the first end portion or the second end portion.