Receiving antenna for multibeam coverage

• US 7,119,754 B2
• Filed: 01/17/2003
• Issued: 10/10/2006
• Est. Priority Date: 01/31/2002
• Status: Expired due to Term

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Lenormand, Regis
• Primary Examiner(s): Ho, Binh V
• Application Number:
  US10/503,097
• Publication Number:
  US 20050088356A1
• Time in Patent Office: 1,362 Days
• Field of Search: 343/834, 343/781.R
• US Class Current: 343/781.00R
• 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 3/2658 Phased-array fed focussing structure

Abstract

The invention relates to a receiving antenna for satellite telecommunications. More specifically, the invention relates to an active antenna comprising a network of elementary sources which is positioned at the focal point of a focusing reflector. According to the invention, said network of sources is disposed on a more or less spherical, concave surface S. The aforementioned arrangement can be used to: (i) improve the efficiency of the optics and (ii) enable the use of polarisation duplexers behind surface S in order to increase the spectral efficiency of the antenna.

Claims

1. Receiving antenna for multispot coverage, comprising at least one focusing reflector (34, 44, 100) and one focal array (30, 110) of individual sources (31) disposed in the focal area of said focusing reflector (34, 44, 100), characterized in that said sources (31) are substantially contiguous and disposed on a concave and approximately spherical surface (S);

and wherein the at least one focusing reflector is concave and faces the one focal array.

2. Antenna according to claim 1, characterized in that a plurality of individual sources (31) are used to form each beam which illuminates a respective spot of said coverage.

3. Antenna according to claim 1, characterized in that one individual source contributes to the formation of a plurality of different beams.

4. Antenna according to claim 1, characterized in that the number of individual sources used in the formation of a single beam is greater than or equal to seven.

5. Antenna according to claim 1, characterized in that the number of individual sources contributing to a beam is not the same for all the beams, being determined as a function of the required characteristics of each beam.

6. Antenna according to claim 1, characterized in that said antenna comprises two concave reflectors (34, 44) in a “

Gregorian”

geometry.

7. Antenna according to claim 1, characterized in that said antenna comprises a single concave reflector (100) in an offset geometry.

8. Antenna according to claim 1, characterized in that said antenna further comprises polarization duplexers (20) behind each individual source.

9. Antenna according to claim 1, characterized in that said antenna is designed to operate with only one polarization and there is no polarization duplexer.

10. Antenna according to claim 1, characterized in that said individual sources have a dimension not exceeding 1.2 times the wavelength.

11. A receiving antenna, comprising

a concave focusing reflector, and

a focal array comprising individual sources disposed in the focal area of the focusing reflector,

wherein the sources are substantially contiguous and disposed on a concave surface;

and the focusing reflector generally faces the focal array, and

wherein the sources are disposed on a spherical or approximately spherical surface.

12. The receiving antenna according to claim 11, wherein the sources are beam emitting or receiving horns.

13. The receiving antenna according to claim 11, further comprising polarization duplexers disposed on a rear surface of the focal array, the polarization duplexers structured to transmit signals to waveguides behind the focal array.

14. The receiving antenna according to claim 11, wherein the sources are disposed on a concave and approximately spherical surface.