Thomson-csf

Thales

Centre National De La Recherche Scientifique

Thomas Merlet

Daniel Dolfi

Mane-Si Laure Lee-Bouhours

Romain Czarny

Sylvain Girard

Olivier Maas

Morgan Queguiner

Jean-Pierre Saddi

Julien Canet

Jean-François Allaeys

Guilllaume Lesueur

Pierre Granger

Michel Renault

The present invention relates to the field of rotary joints, or similar devices, more specifically to optical rotary joints. Embodiments of the invention are directed to a multipathway optical rotary joint, comprising a stationary plane, a moving plane rotatable about a reference axis of rotation and a Dove prism, rotatably placed between the stationary plane and the moving plane. The assembly is configured so that when the moving plane rotates at a speed &#x3c9;, the prism rotates at a speed &#x3c9;/2. The optical pathways are arranged so as to pass through the prism. The Dove prism includes a central optical channel passing an optical wave without undergoing deviation, the axis of the channel being substantially coaxial with the reference axis of rotation. An optical pathway is furthermore arranged in the joint so as to pass through the joint, following an axis substantially coinciding with the reference axis of rotation.

Very high quality channel for multipathway optical rotary joints

A control device for the formation of plural simultaneous radar reception beams in an electronic scanning antenna. The electronic scanning antenna includes an array of detectors of a reception microwave signal arranged in n columns and m rows. The control device makes, in the microwave domain, a first partial combination of the signals received, the first combination being made according to each column. An optical device makes a second partial combination in the optical domain, the optical device including at least n optical sources each producing an optical signal modulated at the frequency of the reception microwave signal by an associated microwave combination signal. The optical signal is divided into r optical signals to obtain nxr optical signals. An optical phase-shifting device is provided for each of the nxr optical signals obtained, and r combining devices combine each group of n optical signals, and r detectors detect the microwave signal f assigned to each group of n optical signals to form r microwave reception beams. The control device can be applied especially to a simple and flexible reconfiguration of reception beams of an electronic scanning antenna.

Control device for the formation of several simultaneous radar reception beams for an electronic scanning antenna

An optical control device for an electronic scanning antenna having at least two controlled radiating elements, and including means for providing first and second mixed light beams, the first light beam polarized according to a first direction and having a first wavelength (&lgr;,), and the second light beam, polarized according to a second direction and having a second wavelength (&lgr;,); at least two optical delay circuits each receiving the first and second mixed light beams and configured to induce complementary delays compared to a determined time value on the first and second beams; chromatic separators each situated at the output of a corresponding one of the delay circuits and configured to separate the light having the first wavelength (&lgr;,) from the light having the second wavelength (&lgr;,); first photodetectors each coupling a corresponding radiating element to a corresponding chromatic separator; second photodetectors each coupling a corresponding chromatic separator to a corresponding first mixer; and second mixers each of which is coupled to a corresponding first mixer, a corresponding radiating element, and a radar signal processor. The first and second light beams are modulated at a transmission frequency (f,) and each of the first mixers mixes the modulated transmission frequency (f,) and an intermediate frequency (f,) to provide a local oscillator frequency (f,) at an output of the first mixer, and the second mixer mixes the local oscillator frequency (f,) and a received signal from a corresponding radiating element including the transmission frequency (f,) and a Doppler frequency (f,) to provide an output frequency which comprises the intermediate frequency augmented by the Doppler frequency (f,&plus;f,) to the radar signal processor.

Optical control device for electronic scanning antenna

Growing community of inventors

Dourdan, France

Thomas Merlet