Demonstration of Optical Control of Steerable Array Antennas

A novel Optically Controlled, Electronically Steerable Phased Array Antenna configuration is proposed. The Antenna utilizes a compact parallel Optical Signal Processor which accomplishes the tasks of transmit/Local Oscillator Signal distribution and phase control and can be used with either space or optical fiber feeds for coupling of RF signals to the different TIP modules of the array. It thus replaces the RF feed network as well as the phase control devices and associated drive and logic circuits required for electronic beam steering in conventional phased arrays. The replaced parts usually account for a large portion of the hardware of conventional phased arrays and thus a very significant reduction in weight and complexity is possible. The space or optical fiber feeds are driven by a novel parallel optical processor which provides the phase control and synchronization of the array. The parallel optical processor, which is the main functional element in the system, is based on Digital Mirror Device (DMD) technology. DMD technology has been developed and used in recent years for electronic display technology by several companies, and is in relatively mature stage. This technology seems to be eminently suited for use in electronically steerable antennas using photonic control, and is proposed for investigation and development in the present proposal. In addition to the weight and cost advantages, photonic antenna control allows significant performance improvement over purely electronic construction, which includes wide band width, true time delay steering and low susceptibility to electromagnetic interference. The proposed effort is expected to result in advanced designs for Optically Controlled, Electronically Steerable Antennas for a large number of applications. Military applications include Fire Control Radars, Airborne Radars and Covert and Mobile Satellite communications. Civilian applications include Air Traffic and Marine Radars, SmartAntennas.