Configurable photonic true-time delay network and its application in multi-beamforming

For the multi-beamforming of an integrated transmitting/receiving optically-controlled phased array antenna, a configurable and flexible photonic true-time delay (PTTD) network is proposed and demonstrated. 16 different time delays from 0–208 ps with a temperature-controlled minimum precision tuning of 0.048 ps °C⁻¹ can be achieved. They are realized by four different laser wavelengths and four groups of cascaded linear chirped fiber Bragg gratings (LCFBGs) whose numbers are 1, 4, 8 and 16, respectively. This value could be extended and reconstructed by cascading more LCFBGs. A wide-range beam steering angle of  −40°–40° and a high-precise turning of 0.2°/5 °C can be obtained by the PTTD array. A larger beam steering range can be reconstructed with specific antenna parameters. Multiple beams for different beam steering angles can be acquired simultaneously. (letter)