SPACE-FILLING MINIATURE ANTENNAS

• US 20110181481A1
• Filed: 02/03/2011
• Published: 07/28/2011
• Est. Priority Date: 01/19/2000
• Status: Active Grant

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: PROS, Jaime ANGUERA, ROZAN, EDOUARD JEAN LOUIS, BALIARDA, CARLES PUENTE
• Granted Patent: US 8,471,772 B2
• Time in Patent Office: Days
• US Class Current: 343/767
• 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 1/38 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 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 5/25 Ultra-wideband [UWB] systems, e.g. multiple resonance systems; Pulse systems
• CPC Class Codes: H01Q 5/357 using a single feed point
• 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 9/40 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

A novel geometry, the geometry of Space-Filling Curves (SFC) is defined in the present invention and it is used to shape a part of an antenna. By means of this novel technique, the size of the antenna can be reduced with respect to prior art, or alternatively, given a fixed size the antenna can operate at a lower frequency with respect to a conventional antenna of the same size.

Claims

1. An apparatus comprising:

an antenna in which an edge of the antenna is shaped as a substantially non-periodic curve;

wherein the non-periodic curve has a box counting dimension larger than one;

wherein the antenna is adapted to radiate across at least two cellular telephone system frequency bands;

wherein the antenna radiates at multiple different operating wavelengths; and

wherein at least one of the operating wavelengths corresponds to an operating wavelength of a cellular telephone system.

2. The apparatus as set forth in claim 1, wherein said apparatus further includes a cell phone and said antenna is located internally within said cell phone.

3. The apparatus as set forth in claim 2, wherein the antenna includes a matching network between an element and at least one of an input connector or transmission line.

4. The apparatus as set forth in claim 2, wherein the non-periodic curve is arranged over two or more surfaces.

5. The apparatus as set forth in claim 4, wherein the antenna is adapted to radiate across at least three cellular telephone system frequency bands.

6. The apparatus as set forth in claim 5, wherein the antenna resonates at least at two different operating wavelengths.

7. The apparatus as set forth in claim 5, wherein said non-periodic curve includes a set of multiple bends in an arrangement that is not self-similar with respect to the entire non-periodic curve.

8. The apparatus as set forth in claim 4, wherein the antenna is adapted to radiate across at least four cellular telephone system frequency bands.

9. The apparatus as set forth in claim 33, wherein said antenna is a monopole antenna.

10. The apparatus as set forth in claim 4, wherein the antenna is adapted to radiate across at least five cellular telephone system frequency bands.

11. The apparatus as set forth in claim 2, wherein of said non-periodic curve includes a set of multiple bends, wherein at least 10 of said bends are arranged on a perimeter of said antenna, wherein at least 10 segments of said non-periodic curve are arranged on a perimeter of a slot or aperture in said antenna, and wherein said slot or aperture is filled or backed by a dielectric substrate.

33. The apparatus as set forth in claim 8, wherein said substantially non-periodic curve shapes an edge of a radiating arm of the antenna.

12. An antenna, comprising:

a radiating element, a perimeter of which is defined by a multi-segment, irregular curve, each of said segments being spatially arranged such that no two adjacent and connected segments form another longer straight segment and none of said segments intersects with another segment other than at the beginning and at the end of said multi-segment, irregular curve to form a closed loop;

wherein the antenna radiates at multiple different operating wavelengths;

wherein a first of the operating wavelengths corresponds to an operating wavelength of a first cellular telephone system;

wherein a second of the operating wavelengths corresponds to an operating wavelength of a second cellular telephone system; and

wherein each segment of the multi-segment, irregular curve is shorter than one tenth of at least one operating free space wavelength of the antenna.

13. The antenna of claim 12, wherein the antenna resonates at a third operating wavelength corresponding to an operating wavelength of said first cellular telephone system, and wherein the antenna resonates at a fourth operating wavelength.

14. The antenna of claim 13, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least two cellular telephone system frequency bands.

15. The antenna of claim 14, wherein the antenna includes a matching network between an element and at least one of an input connector or transmission line.

16. The antenna of claim 14, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.5.

17. The antenna of claim 14, wherein said multi-segment, irregular curve comprises at least 25 segments.

18. The antenna of claim 13, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least three cellular telephone system frequency bands.

19. The antenna of claim 18, wherein said antenna is a patch antenna, wherein at least 10 segments of said multi-segment, irregular curve are arranged on a perimeter of said antenna, wherein at least 10 segments of said multi-segment, irregular curve are arranged on a perimeter of a slot or aperture in said antenna, and wherein said slot or aperture is filled or backed by a dielectric substrate.

20. The antenna of claim 18, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.4.

21. The antenna of claim 13, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least four cellular telephone system frequency bands.

22. The antenna of claim 21, wherein said antenna is an internal antenna in a portable communications device.

23. The antenna of claim 21, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.3.

24. The antenna of claim 13, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least five cellular telephone system frequency bands.

25. The antenna of claim 24, wherein said antenna is a monopole antenna.

26. The antenna of claim 24, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.2.

27. The antenna of claim 24, wherein one of said cellular telephone system frequency bands is GSM 900.

28. The antenna of claim 13, wherein the multi-segment, irregular curve is arranged over two or more surfaces.

29. The antenna of claim 28, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.4.

30. The antenna of claim 28, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least three cellular telephone system frequency bands.

31. The antenna of claim 28, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least four cellular telephone system frequency bands.

32. The antenna of claim 28, wherein the antenna is adapted to radiate and receive electromagnetic waves across at least five cellular telephone system frequency bands.

34. The antenna of claim 25, wherein said multi-segment, irregular curve shapes a perimeter of a radiating arm of the antenna.

35. The antenna of claim 12, wherein said multi-segment, irregular curve shapes less than an entire perimeter of the radiating element.

36. The antenna of claim 12, wherein said multi-segment, irregular curve shapes an entire perimeter of the radiating element.