SURFACE FOR FILTERING A PLURALITY OF FREQUENCY BANDS

• US 20130127651A1
• Filed: 04/13/2011
• Published: 05/23/2013
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Centre Technique De L'Industrie Des Papiers, Cartons Et Celluloses, Institut Polytechnique De Grenoble
• Original Assignee: Centre Technique De L'Industrie Des Papiers, Cartons Et Celluloses
• Inventors: De Barros, Fabien, Eymin-Petot-Tourtollet, Guy, Lemaitre-Auger, Pierre, Vuong, Tn-Phu
• Granted Patent: US 9,065,180 B2
• Time in Patent Office: Days
• US Class Current: 342/4
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective

Abstract

The invention relates to a surface suitable for filtering a plurality of frequency bands, said surface including a set of separate identical basic conductive units (31) that are reproduced in a periodic arrangement on a dielectric substrate (10). The basic unit includes: a tripole consisting of three identical segments (12) that extend radially from a center (14); and two arms (32) that extend symmetrically from an intermediate point of each segment, said intermediate point being located at a common distance (D_b) from the center (14) for each of the segments (12). The general directions of both arms form an angle of approximately 120° and define an arrowhead pointed toward the outside, wherein the arms (32) corresponding to two separate segments (12) do not intersect.

Claims

1. A surface capable of filtering a plurality of frequency bands, this surface comprising a set of separate identical elementary conductive patterns, repeated according to a periodic layout on a dielectric support, the elementary pattern comprising:

a tripole formed of three identical segments extending in a star from a center; and

two branches extending symmetrically from an intermediate point of each segment, this intermediate point being located at a same distance from the center for each of the segments, the general directions of the two branches forming an angle of approximately 120° and

defining an outward-pointing arrowhead, the branches associated with two different segments being non-secant,

the elementary pattern being repeated by translation along each of the directions of the segments so that a same distance separates each end of a segment of a pattern from the center of a neighboring pattern.

2. The surface of claim 1, wherein the segments of the tripole form, two-by-two, angles of approximately 120°

.

3. The surface of claim 1, wherein the elementary pattern further comprises two first identical fins extending symmetrically from the end of each segment, the first fins forming an angle of approximately 120°

and defining an arrowhead directed towards the outside of the pattern.

4. The surface of claim 1, wherein the elementary pattern further comprises two first identical fins extending from the free end of each branch, each second fin forming an angle of approximately 60°

with the general direction of the branch.

5. The surface of claim 4, wherein the second fins of each branch form together an angle of approximately 120°

and define an arrowhead directed towards the outside of the pattern.

6. The surface of claim 4, wherein the second fins of each branch are aligned along a same direction, this direction intersecting the direction of the segment from which the branch originates.

7. The surface of claim 1, wherein the branches comprise at least one crenel-shaped extension along a direction intersecting the general direction of the branch.

8. The surface of any of claim 1, capable of filtering three frequency bands respectively centered on 0.9, 1.8, and 2.1 GHz.

9. The surface of claim 1, capable of filtering two frequency bands respectively centered on 2.4 and 5.4 GHz.

10. The surface of claim 1, wherein the dielectric support is a paper- or cardboard-type support and the conductive patterns are formed by printing with a conductive ink.

11. A use of the surface of claim 1 to filter three frequency bands located within the range from 0.9 to 5.4 GHz, wherein the overall dimensions of an elementary pattern approximately range from 1 to 10 centimeters, the lengths of each of these segments, branches, and fins being adjusted to select the three targeted frequency bands.