SPACE-FILLING MINIATURE ANTENNAS

• US 20090109101A1
• Filed: 12/31/2008
• Published: 04/30/2009
• Est. Priority Date: 01/19/2000
• Status: Active Grant

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: ROZAN, EDOUARD JEAN LOUIS, BALIARDA, CARLES PUENTE, PROS, JAUME ANGUERA
• Granted Patent: US 8,212,726 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• 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. A portable telecommunications device, comprising:

circuitry for communicating with a telecommunications network; and

an antenna shaped to have characteristics of a space-filling curve.

2. The portable telecommunications device of claim 1, wherein the antenna of said portable telecommunications device receives signals at a plurality of frequencies to give coverage to at least three communication services, wherein at least one of said communication services is selected from the group consisting essentially of cellular telephone services:

GSM 900, GSM1800, UMTS.

3. The portable telecommunications device of claim 2, wherein the antenna of said portable telecommunications device provides coverage to at least one communication service.

4. The portable telecommunications device of claim 2, wherein the at least one communication service is UMTS.

5. The portable telecommunications device of claim 1, wherein the antenna includes—

a multi-segment curve located completely within a radian sphere defined around the radiating element.

6. The portable telecommunications device of claim 5, wherein no part of said multi-segment curve intersects another part of the multi-segment curve.

7. The portable telecommunications device of claim 5, wherein no part of said multi-segment curve intersects another part other than at its beginning and end.

8. The portable telecommunications device of claim 5, wherein said multi-segment curve features a box-counting dimension larger than 17.

9. The portable telecommunications device of claim 8, wherein the box-counting dimension comprises a 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.

10. The portable telecommunications device of claim 5, wherein the multi-segment curve forms a slot in a conductive surface of a radiating element.

11. The portable telecommunications device of claim 5, wherein the multi-segment curve lies on a flat surface.

12. The portable telecommunications device of claim 5, wherein the multi-segment curve lies on a curved surface.

13. The portable telecommunications device of claim 5, wherein the multi-segment curve extends across a surface lying in more than one plane.

14. The portable telecommunications device of claim 5, wherein the antenna includes a slot in a conducting surface, wherein said multi-segment curve defines the slot in the conducting surface, and wherein said slot is backed by a dielectric substrate.

15. The portable telecommunications device of claim 5, wherein a portion of the multi-segment curve includes at least ten bends.

16. The portable telecommunications device of claim 15, wherein the radius of curvature of each of said at least ten bends is smaller of a tenth of the longest operating free-space wavelength of the antenna.

17. The portable telecommunications device of claim 5, wherein a portion of said multi-segment curve is not self-similar with respect to the entire multi-segment curve.