New guided-wave optical beam former for phased array antennas

In this paper we present the theoretical investigation and design of a guided-wave optical processor suitable for beam forming of a linear phased array antenna and based on a planar structure involving two acousto-optic transducers (AOT) having contra-directional surface acoustic wave (SAW) propagation. By applying two different periodic microwave signals to the transducers, the phase content of the output field distribution in the transverse direction with respect to the propagation one is a linear function of the applied frequency difference and can be used to drive a photodiode array connected to the phased array antenna by a RF circuit. The performance of the circuit has been also defined with respect to the resulting beam forming and to the radiation pattern characteristics of the driven microwave array. In this study, acousto-optic interaction on a lithium niobate planar-waveguide has been considered.