Broadband Lithium Niobate Integrated Microwave Photonic Beamforming Chip

Abstract Squint‐free integrated microwave photonic (IMWP) beamforming chips based on optical true‐time delay lines are key building blocks for future miniature microwave photonic radars. Here, to the best of the knowledge, the first IMWP beamforming chip on a thin‐film lithium niobate (TFLN) platform is reported. The chip consists of an electro‐optic modulator and a 4‐channel optical beamforming network based on 4‐bit thermo‐optic switchable delay lines, showing broad operating bandwidth from 2 to 50 GHz. Eleven different beamforming angles in a wide range from −75.42° to 77.58° are supported for a 40 GHz RF signal. The successful demonstration of this chip further boosts the development of TFLN‐based multifunctional IMWP systems and opens avenues for practical applications of broadband on‐chip radars.