Patent ID: 6313792
Filing Date: 2001-11-06
Classification: H01Q

Abstract:
Optical control device for an electronic scanning antenna having at least two controlled radiating elements, comprising:means for providing first and second mixed light beams, said first light beam polarized according to a first direction and having a first wavelength (.lambda..sub.1), and said second light beam, polarized according to a second direction and having a second wavelength (.lambda..sub.2);means for modulating said first and second light beams at a transmission frequency of the antenna;a plurality of optical delay circuits each receiving mixed first and second light beams and configured to induce complementary delays compared to a determined time value on said first and second beams;a plurality of chromatic separators each situated at an output of a corresponding one of said delay circuits and configured to separate the light having the first wavelength (.lambda..sub.1) from the light having the second wavelength (.lambda..sub.2);a plurality of first photodetectors each coupling a corresponding radiating element to a corresponding chromatic separator;a plurality of second photodetectors each coupling a corresponding chromatic separator to a corresponding first mixer; andplurality of second mixers each of which is coupled to a corresponding first mixer, a corresponding radiating elements, and a radar signal processor;wherein said first and second light beams are modulated at a transmission frequency (f.sub.e) and each of said first mixers mixes the modulated transmission frequency (f.sub.e) and an intermediated frequency (f.sub.i) to provide a local oscillator frequency (f.sub.OL) at an output of the first mixer, and said second mixer mixes said local oscillator frequency (f.sub.OL) and a received signal from a corresponding radiating element including said transmission frequency (f.sub.e) and a Doppler frequency (f.sub.D) to provide an output frequency which comprises said intermediate frequency augmented by said Doppler frequency (f.sub.i +f.sub.D) to the radar signal processor.