Integrated photonic K_u-band beamformer chip with continuous amplitude and delay control

We present the first demonstration of a broadband and continuously tunable integrated optical beamforming network (IOBFN) capable of providing continuously tunable true-time-delay up to 236 ps over the entire DVB-S band (10.7–12.75 GHz), realized with a CMOS compatible process. The tunable delays are based on reconfigurable optical ring resonators in conjunction with a single optical sideband filter integrated on the same optical chip. The delays and filter responses are software programmable. Four tunable delay lines are integrated on a single chip and configured to feed a 16-element linear antenna array. The broadband beam steering capability of the proposed IOBFN is demonstrated by the squint-free antenna pattern generated from the measured RF amplitude and phase responses of the optical delay line.