Array of optically-controlled elements for the diffusion of electromagnetic energy

• US 4,896,033 A
• Filed: 01/17/1989
• Issued: 01/23/1990
• Est. Priority Date: 04/22/1986
• Status: Expired due to Fees

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Gautier, Francois
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): Shami, Khaled
• Application Number:
  US07/298,268
• Time in Patent Office: 371 Days
• Field of Search: 250/201, 250/215, 343/762, 343/754, 332/3, 378/119, 455/607
• US Class Current: 250/215
• CPC Class Codes: H01Q 3/44 varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element

Abstract

The main object of the invention is an array of optically-controlled elements for the diffusion of electromagnetic energy. The invention pertains to an array capable of diffracting the electromagnetic energy which illuminates it, certain elements of the said array being capable of modulation. The device according to the invention comprises photodetectors which can be used for the optical modulation of the emitting/reflecting elements, whether diffusing or diffracting. The optical modulation provides for the individual control of each radiating element up to very high frequencies. Furthermore, the device according to the invention can be used to reduce the complexity of an array by doing away with the control wiring. The invention can be applied chiefly to the making of radar-testing devices, for example the simulation of bright points, the ultra-high-frequency tomography of the human body and the making of beacons.

Claims

1. A network for the controlled diffusion of electromagnetic energy, said network receiving a radioelectric wave of frequency f_o from a first outside source and receiving a modulated light ray from a second outside source, said network comprising:

photodetector means for receiving said light ray and converting said light ray to an electrical signal of frequency f_m ;

a dipole;

a variable capacity diode connected between the two respective parts of said dipole;

means for controlling the polarization of the variable capacity diode; and

wherein said dipole receives said radioelectric wave of frequency of and said electric signal of frequency f_m such that a modulated signal of frequency f=f_o +Kf_m is diffused from said dipole and said variable capacity diode omnidirectionally.

5. A network according to claim 1, wherein:

when K equals ±

1, amplitude modulation occurs.

6. A network according to claim 1, wherein:

when K is an integer, phase modulation occurs.

7. A network according to claim 1, further comprising:

amplification means connected to said photodetector means and said dipole.

8. A network according to claim 7, wherein:

said amplification means is a Darlington pair of transistors.

9. A network according to claim 1, wherein:

the electromagnetic energy is ultra-high frequency energy.

2. An array for the controlled diffusion of electromagnetic energy, said array comprising a plurality of networks, each network of said plurality of networks receiving a radioelectric wave of frequency f_o from a first outside source and receiving a modulated light ray from a second outside source, each network comprising:

photodetector means for receiving said light ray and converting said light ray to an electrical signal of frequency f_m ;

a dipole;

a variable capacity diode connected between the two respective parts of said dipole;

means for controlling the polarization of the variable capacity diode; and

wherein said dipole receives said radioelectric wave of frequency f_o and said electric signal of frequency f_m such that a modulated signal of frequency f=f_o +Kf_m is diffused from said dipole and said variable capacity diode omnidirectionally.

3. An array according to claim 2, further comprising:

amplification means, for amplification of said electrical signal f_m, coupled to said dipole.

4. An array according to claim 2, further comprising:

a chamber enclosing said array;

at least one laser located in said chamber;

a laser beam defining device to direct the modulated light ray from said at least one laser to the photodetector means; and

a control circuit connected to said at least one laser and said deflecting device, said control circuit controlling the frequency of said modulated light ray and properly orienting the laser beam deflecting device.