Multiple-beam antenna with photonic bandgap material

• US 20060125713A1
• Filed: 10/23/2003
• Published: 06/15/2006
• Est. Priority Date: 10/24/2002
• Status: Active Grant

• Current Assignee: Centre National D'Etudes Spatiales, Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Centre National De La Recherche Scientifique, Centre National D'Etudes Spatiales
• Inventors: Legay, Herve, Dumon, Patrick, Chantalat, Regis, Thevenot, Marc, Jecko, Bernard, Monediere, Thierry, Leger, Ludovic
• Granted Patent: US 7,233,299 B2
• Time in Patent Office: Days
• US Class Current: 343/909
• CPC Class Codes: H01Q 15/006 Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces
• CPC Class Codes: H01Q 19/17 the primary radiating source comprising two or more radiating elements H01Q19/15, H01Q25/00 take precedence
• CPC Class Codes: H01Q 25/007 using two or more primary active elements in the focal region of a focusing device for operation on different wavebands H01Q5/22
• CPC Class Codes: H01Q 5/00 Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements combinations of separate active antenna units operating in different wavebands and connected to a common feeder system H01Q21/30
• CPC Class Codes: H01Q 5/28 Arrangements for establishing polarisation or beam width over two or more different wavebands

Abstract

A system includes a device for focusing electromagnetic waves, and a multiple-beam antenna. The antenna includes: a photonic bandgap material (20) having at least one band gap, at least one periodicity defect (36) of the photonic bandgap material so as to produce at least one narrow bandwidth within the bandgap material, and excitation elements (40 to 43) for transmitting and/or receiving electromagnetic waves within the at least one narrow bandwidth, the elements being arranged relative to one another so as to produce overlapping radiating spots.

Claims

1-11. -11. (canceled)

12. A system for transmitting and/or receiving electromagnetic waves comprising:

a device for focusing the electromagnetic waves transmitted and/or received by the system on a focal point, and

a transmitter and/or receiver of electromagnetic waves placed roughly at the focal point so as to transmit and/or receive said electromagnetic waves, wherein

it comprises a multiple-beam antenna, the outer radiating surface of which is placed roughly on the focal point so as to form said transmitter and/or receiver of electromagnetic waves,

the antenna comprises;

a photonic bandgap material designed to filter the electromagnetic waves spacewise and frequencywise, this photonic bandgap material having at least one bandgap and forming an outer surface radiating in transmit and/or receive mode,

at least one periodicity defect of the photonic bandgap material so as to produce at least one narrow bandwidth within said at least one bandgap of this photonic bandgap material, and

an excitation device for transmitting and/or receiving electromagnetic waves within said at least one narrow bandwidth produced by said at least one defect, this excitation device being designed to work simultaneously at least about a first and a second separate working frequencies,

the excitation device includes a first and a second excitation elements, separate from and independent of each other, each designed to transmit and/or receive electromagnetic waves, the first excitation element being designed to work at the first working frequency and the second excitation element being designed to work at the second working frequency,

the or each periodicity defect of the photonic bandgap material forms a leaky resonating cavity presenting a constant height in a direction perpendicular to said radiating outer surface, and predefined lateral dimensions parallel to said radiating outer surface,

the first and the second working frequencies are designed to excite the same resonance mode of a leaky resonant cavity, this resonance mode being established identically regardless of the lateral dimensions of the cavity, so as to create on said outer surface respectively a first and a second radiating spots, each of these radiating spots representing the origin of a beam of electromagnetic waves radiated in transmit and/or receive mode by the antenna,

each of the radiating spots has a geometric center, the position of which depends on the position of the excitation element producing it and the area of which is greater than that of the radiating element producing it, and

the first and the second excitation elements are placed relative to each other such that the first and the second radiating spots are positioned on the outer surface of the photonic bandgap material alongside each other and partially overlap.

13. The system as claimed in claim 12, wherein the device for focusing the electromagnetic waves is a parabolic reflector.

14. The system as claimed in claim 12, wherein the device for focusing the electromagnetic waves is an electromagnetic lens.

15. The system as claimed in claim 12, wherein:

each radiating spot is roughly circular, the geometric center corresponding to a maximum transmitted and/or received power and the periphery corresponding to a maximum transmitted and/or received power equal to a fraction of the maximum transmitted and/or received power at its center, and

the distance, in a plane parallel to the outer surface, separating the geometric centers of the two excitation elements is strictly less than the radius of the radiating spot produced by the first excitation element added to the radius of the radiating spot produced by the second excitation element.

16. The system as claimed in claim 12, wherein the geometric center of each radiating spot is placed on the line perpendicular to said radiating outer surface and passing through the geometric center of the excitation element producing it.

17. The system as claimed in claim 12, wherein the first and the second excitation elements are placed inside one and the same cavity.

18. The system as claimed in claim 17, wherein the first and the second working frequencies are situated within the same narrow bandwidth created by this same cavity.

19. The system as claimed in claim 12, wherein the first and the second excitation elements are each placed inside separate resonating cavities, and the first and the second working frequencies are designed each to excite a resonance mode independent of the lateral dimensions of their respective cavities.

20. An antenna as claimed in claim 19, wherein it comprises an electromagnetic radiation reflector plane associated with the photonic bandgap material, this reflector plane being distorted so as to form said separate cavities.

21. The system as claimed in claim 12, wherein the or each cavity is of parallelepipedal shape.

22. The system as claimed in claim 12, wherein the device for focusing the electromagnetic waves comprises a reflector in half-cylinder shape, and the photonic bandgap material of the antenna has a convex surface corresponding to the half-cylinder-shaped surface of the reflector.