2-DIMENSIONAL OPTICAL ARCHITECTURE FOR TIME-DELAY BEAM FORMING IN A PHASED-ARRAY ANTENNA

We propose and experimentally demonstrate a new two-dimensional optical architecture based on polarization switching by N spatial light modulators that provides 2N time delays to a phased-array antenna of p X p radiating elements. Moreover the 0 to 2-pi-phase of the microwave signals is optically controlled by a liquid-crystal spatial light modulator that operates in the birefringent mode. The microwave signal originates from the coherent detection of a dual-frequency laser beam obtained with an acousto-optic frequency shifter. Preliminary experimental results obtained at a microwave frequency f = 1.85 GHz are presented.