DEVICE FOR PRODUCING OPTICALLY-CONTROLLED INCREMENTAL TIME DELAYS

摘要

The present invention includes time delay devices and time delay systems. The invention also includes machines and instruments using those aspects of the invention. The invention may also be used to upgrade, repair, or retrofit existing machines or instruments, using methods and components known in the art. The present invention comprises a true time device that falls into the free-space category but uses a multiple-pass optical cell with a beam splitter (28) and refocusing mirrors (13, 14, 24, 25) that have the advantage of avoiding beam spreading problems. The approach differs from previous free-space approaches in that it uses only one optical switch or spatial light modulator (12) instead of one or more switches for each bit. In one approach, a microwave signal for each antenna element may be modulated onto an optical beam. After the individual optical beams are delayed by the desired amount of time through the system, the signal may then be down-converted to microwave signals for further processing. This process may be used in either the transmit or the receive mode of a phased array radar.