Calibration of an antenna array

• US 9,547,066 B2
• Filed: 10/28/2014
• Issued: 01/17/2017
• Est. Priority Date: 10/29/2013
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Bories, Serge, Ghattas, Lama, Picard, Dominique
• Primary Examiner(s): Le, Son
• Assistant Examiner(s): Zakaria, Akm
• Application Number:
  US14/525,423
• Publication Number:
  US 20150115978A1
• Time in Patent Office: 812 Days
• Field of Search: 324/601
• US Class Current: 1/1
• CPC Class Codes: G01N 21/63 optically excited
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: G01S 7/4021 of receivers
• CPC Class Codes: H01Q 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 15/08 formed of solid dielectric material
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H01Q 5/22 RF wavebands combined with non-RF wavebands, e.g. infrared or optical

Abstract

An antenna system including at least one antenna connected to a captured signal processing receiver, an antenna protection radome; and a plurality of electro-optical probes distributed on or inside of the radome.

Claims

1. A method of calibrating a receiver of an antenna system comprising at least one antenna connected to the receiver, an antenna protection radome, and a plurality of electro-optical probes distributed on or inside of the radome, comprising the steps of:

a. transmitting an unmodulated radio signal at a first frequency;

b. transmitting an optical signal intended to excite the probes at a second frequency to modulate the radio signal;

c. analyzing the signals received from the at least one antenna; and

d. determining correction coefficients to be applied to the signals delivered by the at least one antenna,

wherein steps a) to d) are repeated for a plurality of values of the first frequency.

2. The method of claim 1, wherein the analysis of step c is performed at the first frequency and at frequencies corresponding to this first frequency, respectively decreased and increased by the second frequency.

3. The method of claim 1, wherein steps b and c are successively carried out for each of said probes.

4. An antenna system comprising:

at least one antenna connected to a captured signal processing receiver;

an antenna protection radome; and

a plurality of electro-optical probes distributed at the surface or within the thickness of the radome and configured to modulate, at a second frequency, an unmodulated radio signal incident on each of the electro-optical probes,

wherein said receiver demodulates in a calibration phase, signals backscattered by the probes to determine correction coefficients for signals received by the at least one antenna.

5. The system of claim 4, further comprising a laser intended to excite, through optical fibers, electro-optical probes.

6. The system of claim 4, further comprising a device for transmitting a radio signal.

7. The system of claim 4, wherein the electro-optical probes are distributed at regular angular positions.

8. The system of claim 4, wherein the receiver calculates and stores correction coefficients for the signals delivered by the at least one antenna.

9. The system of claim 4, comprising a plurality of antennas forming an antenna array.