Continuously delay-time tunable-waveguide hologram module for X-band phased-array antenna

Tunable optical true time-delay modules based on a dispersive waveguide hologram are presented to provide continuous radio-frequency beam scanning for an X-band (8-12 GHz) phased-array antenna system. The true timedelay modules operating in the 1550-nm region were fabricated with continuously tunable time delays from 5 to 64 ps. The far-field radiation patterns were measured with different delay combinations and the continuity of the scanning angles from 35 to 55 was experimentally confirmed at X-band frequencies.