Microwave Photonic Beamforming System Based on an On-Chip Multi-Wavelength Laser and Integrated Waveguide Bragg Grating

An ultra-compact RF beamforming system based on an on-chip multi-wavelength laser and integrated waveguide Bragg grating is proposed. Unlike the conventional microwave photonic RF beamforming systems that typically use laser array and/or optical true time delay (OTTD) array, the proposed system utilizes only a single laser to generate multi-wavelength optical carriers with an equal wavelength spacing from 1533 to 1540 nm, and a dispersive OTTD device based on a silicon-nitride spiral Bragg grating waveguide (SBGW) with a bandwidth of 30 nm and a dispersion coefficient of 10 ps/nm. The experiment demonstrated that no beam squint is observed within 6-10 GHz. The proposed beamforming system features miniaturization and lightweight, making it potentially applicable in fields such as satellite and unmanned aerial vehicle systems.