BROADSIDE HIGH-DIRECTIVITY MICROSTRIP PATCH ANTENNAS

• US 20090046015A1
• Filed: 09/04/2008
• Published: 02/19/2009
• Est. Priority Date: 01/24/2003
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: Fractus SA
• Inventors: Baliarda, Carles Puente, Borau, Carmen Borja, Pros, Jaume Anguera
• Granted Patent: US 8,026,853 B2
• Time in Patent Office: Days
• 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 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 5/385 Two or more parasitic elements
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

High-directivity microstrip antennas comprising a driven patch and at least one parasitic element placed on the same plane, operate at a frequency larger than the fundamental mode of the driven patch in order to obtain a resonant frequency with a high-directivity broadside radiation pattern. The driven patch, the parasitic elements and the gaps between them may be shaped as multilevel and/or Space Filling geometries. The gap defined between the driven and parasitic patches according to the invention is used to control the resonant frequency where the high-directivity behaviour is obtained. The invention provides that with one single element is possible to obtain the same directivity than an array of microstrip antennas operating at the fundamental mode.

Claims

1. A high-directivity microstrip patch antenna comprising a driven patch and at least one parasitic patch coupled to said driven patch by means of a gap, the driven and parasitic patches being placed on the same plane defined by a dielectric substrate, characterized in that the resonant frequency of the antenna is larger than the frequency of the fundamental mode, said resonant frequency being determined by the shape and dimensions of said gap for a given patch size, the antenna having a high-directivity radiation pattern at said resonant frequency.

2. An antenna according to claim 1 characterized in that the resonant frequency of the antenna is at least 20% larger than the frequency of the fundamental mode.

3. An antenna according to claim 1 or 2 characterized in that the gap between the driven patch and parasitic patch or patches is defined by a space-filling curve.

4. An antenna according to claim 1 or 2 characterized in that the gap between the driven patch and parasitic patch or patches is a straight line.

5. An antenna according to claim 1 characterised in that at least a part of the driven patch and at least a part of the parasitic patch or patches are defined by a space-filling curve or a multilevel structure.

6. An antenna according to claim 1 characterized in that the driven patch and the parasitic patch or parches are connected by a coplanar transmission line across the gap in between, the antenna having a first resonant frequency which is lower than the fundamental mode of the driven element, and a second resonant frequency higher than said fundamental mode where the high-directivity occurs, the antenna therefore having a dual band operation.

7. An antenna according to claim 1 characterised in that it comprises one driven patch and four parasitic patches, the driven patch having four sides and each one of the parasitic patches being coupled by a gap to one of the sides of the driven patch.

8. An antenna according to claim 1 characterised in that it comprises one driven patch and a parasitic patch, the perimeter of said driven and parasitic patch being defined by the Koch fractal.

9. An antenna according to claim 1 characterized in that it comprises one driven patch and a parasitic patch, wherein the driven and parasitic patch are multilevel geometries based on the Sierpinski bowtie.

10. An antenna according to claim 1 characterised in that the gap between the driven and parasitic or parasitics patches is defined by a space-filling curve based on the Hilbert fractal.