Photonic True-Time Delay Beamforming Based on Polarization-Domain Interferometers

In this paper, we propose a novel photonic true-time delay beamforming system for phased array antennas. The system relies on tunable delay lines which are based on Mach-Zehnder delay interferometers (MZDIs) with tunable coupling ratio. As the MZDIs are implemented on the polarization domain, a single optical source and a single piece of polarization maintaining fiber are required. The proposed implementation is theoretically assessed and beam squinting is investigated by simulation. A proof-of-concept experiment that validates the operation principle of the proposed delay lines is presented.