Integrated Microphotonic Tuneable Delay Lines for Beam Steering in Phased Array Antennas

Beam steering in phased array antennas for some demanding terrestrial and space applications needs ultra-wide band true-time tunable delay lines preventing the beam squint phenomenon. Recent advances in the field of integrated microphotonics have allowed the demonstration of compact chip-scale delay lines with fast and low-power tuning mechanisms. For the tuning, several approaches have been theoretically and experimentally investigated and among them, very promising results have been obtained by using graphene in resonant delay lines based on the slow light effect. In this paper, after a brief review on resonant microphotonic tunable delay lines, some selected recent results on an ultra-compact graphene-based optical delay line including a silicon Bragg grating, are proposed.