Optical control device for electronic scanning antenna

Abstract

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,+f,) to the radar signal processor.