Fiber-optic control of a two-dimensional, true time-steered array transmitter

The use of fiber optic control for phased array radar promises to reduce or eliminate many of the traditional problems associated with these systems such as excessive weight and size and susceptibility to electromagnetic interference. More importantly, optical control techniques are currently the only methods capable of enabling the use of true time-delay beam steering which allows for a wide instantaneous bandwidth and squint-free operation. We describe a two-dimensional, fiber-optic, true time-delay control system capable of squint-free steering of an ultrawideband array. The system demonstrates independent /spl plusmn/30/spl deg/ azimuth and /spl plusmn/30/spl deg/ elevation steering of a 4/spl times/4 array of flared-notch elements over a 6 to 18 GHz bandwidth. We believe this is the first demonstration of a system with such capabilities. Also, the design of the demonstrated system allows for transitioning to larger, real-world ultrawideband array transmitters.