Optical-controlled true-time delay devices and their application in phased array antenna system

Military and civilian wireless communication systems require compact phased array antenna systems with high performance. Conventional phase-shifter based techniques suffer from beam squint effect which causes undesirable changing of beam steering angle when the microwave frequency changes in phased array antenna system. Optical true-time delay techniques open the possibility of ultra-wide bandwidth antenna systems, while at the same time meeting the stringent weight and size requirements. Continuously tunable true-time delay techniques can provide continuous beam-steering ability without mechanical movement for the phased array antenna systems. With advanced optoelectronic techniques, fast wavelength tuning speed (~ns) is possible. This may provide viable solutions to the high-speed phased array antenna systems. This dissertation describes holographic-gratings based optical continuous-tunable true-time delay devices and their application in a X-band phased array antenna system. The design, development and measurements of the true-time delay devices and the X-band phased array antenna system are explained in this dissertation.