MONOLITHIC INTEGRATED OPTICAL TIME DELAY NETWORK FOR ANTENNA BEAM STEERING

摘要

A time delay network for phased array antenna beam steering employs a waveguide network as the delay element in a monolithic integration with other optical and electronic elements on a single substrate. A plurality of optical time delay stages are cascaded to form the delay network, with each stage having a selectable delay time. Each stage preferably has a reference or nominal time delay branch, and at least one other finite time delay branch. The lengths of the delay waveguides vary from stage to stage, permitting a high time delay resolution with a relatively small number of separate waveguides. The desired time delay is selected either by directing the modulated laser light into only one of the waveguide branches in each stage by means of waveguide switches or by splitting the light into all the waveguide branches of a stage and then activating only the detector connected to the desired delay waveguide. A variety of cascading schemes and waveguide layouts can be used to implement the time delay network.