Space-filling miniature antennas

• US 8,471,772 B2
• Filed: 02/03/2011
• Issued: 06/25/2013
• Est. Priority Date: 01/19/2000
• Status: Expired due to Fees

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: Puente Baliarda, Carles, Rozan, Edouard Jean Louis, Anguera Pros, Jaime
• Primary Examiner(s): Nguyen, Hoang V
• Application Number:
  US13/020,034
• Publication Number:
  US 20110181481A1
• Time in Patent Office: 873 Days
• Field of Search: 343/700.MS, 343/702
• US Class Current: 343/700.MS
• 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:

a single antenna having a surface that radiates and receives electromagnetic waves, an entirety of an edge enclosing the surface shaped as a substantially non-periodic curve;

the non-periodic curve has a box counting dimension larger than one with the box-counting dimension computed as the slope of a substantially straight portion of a line in a log-log graph over at least one octave of scales on a horizontal axis of the log-log graph; and

the single antenna functions across each of at least two cellular telephone system frequency bands.

2. The apparatus as set forth in claim 1, wherein said apparatus is a cellular telephone and said single antenna is located internally within said cellular telephone.

3. The apparatus as set forth in claim 2, wherein the single antenna comprises 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 single antenna functions across each of at least three cellular telephone system frequency bands.

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

7. The apparatus as set forth in claim 4, wherein the single antenna functions across each of at least four cellular telephone system frequency bands.

8. The apparatus as set forth in claim 7, wherein said single antenna is a monopole antenna.

9. The apparatus as set forth in claim 4, wherein the single antenna functions across at least five cellular telephone system frequency bands.

10. A single antenna, comprising:

a single radiating element having 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;

a matching network between the single radiating element and an input connector or transmission line;

the single antenna simultaneously receives electromagnetic waves of at least a first and a second operating wavelength and radiates at multiple operating wavelengths;

the first of the operating wavelengths corresponds to an operating wavelength within a first frequency band of a first cellular telephone system;

the second of the operating wavelengths corresponds to an operating wavelength within a second frequency band of a second cellular telephone system;

the first and second frequency bands being non-overlapping; and

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

11. The antenna of claim 10, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.5, the box-counting dimension is computed as the slope of a substantially straight portion of a line in a log-log graph over at least an octave of scales on the horizontal axes of the log-log graph.

12. The antenna of claim 10, wherein said multi-segment, irregular curve comprises at least 25 segments.

13. The antenna of claim 10, wherein the single antenna radiates and receives electromagnetic waves across each of at least three cellular telephone system frequency bands.

14. The antenna of claim 13, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.4, the box-counting dimension is computed as the slope of a substantially straight portion of a line in a log-log graph over at least an octave of scales on the horizontal axes of the log-log graph.

15. The antenna of claim 10, wherein the single antenna radiates and receives electromagnetic waves across each of at least four cellular telephone system frequency bands.

16. The antenna of claim 15, wherein said single antenna is an internal antenna in a portable communications device.

17. The antenna of claim 15, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.3, the box-counting dimension is computed as the slope of a substantially straight portion of a line in a log-log graph over at least an octave of scales on the horizontal axes of the log-log graph.

18. The antenna of claim 10, wherein the single antenna radiates and receives electromagnetic waves across each of at least five cellular telephone system frequency bands.

19. The antenna of claim 18, wherein said single antenna is a monopole antenna.

20. The antenna of claim 18, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.2, the box-counting dimension is computed as the slope of a substantially straight portion of a line in a log-log graph over at least an octave of scales on the horizontal axes of the log-log graph.

21. The antenna of claim 18, wherein one of said cellular telephone system frequency bands is GSM 900.

22. The antenna of claim 10, wherein the multi-segment, irregular curve is arranged over two or more surfaces.

23. The antenna of claim 22, wherein said multi-segment, irregular curve has a box-counting dimension equal to or greater than 1.4, the box-counting dimension is computed as the slope of a substantially straight portion of a line in a log-log graph over at least an octave of scales on the horizontal axes of the log-log graph.

24. The antenna of claim 22, wherein the single antenna radiates and receives electromagnetic waves across each of at least three cellular telephone system frequency bands.

25. The antenna of claim 22, wherein the single antenna radiates and receives electromagnetic waves across at least four cellular telephone system frequency bands.

26. The antenna of claim 22, wherein the single antenna radiates and receives electromagnetic waves across each of at least five cellular telephone system frequency bands.