An Active Integrated Broadband Multi-Beamformer Using Optical True-Time Delay Induced Blass Matrix

An active integrated broadband photonics multi-beamformer using optical true-time delay induced Blass matrix is designed and demonstrated. The multi-beamformer is constructed on a standard silicon-on-insulator platform, incorporating on-chip modulator array and photodetector array alongside a broadband multi-beamforming network. The network utilizes a Blass matrix architecture based on optical true-time delay to precisely control the power and delay of input microwave signals. Furthermore, wavelength division multiplexing technology achieved by multi-wavelength lasers is used to decouple the signals from different channels, enabling the simultaneous multi-beamforming. Radio-frequency characterizations indicate that the active integrated broadband photonic multi-beamformer is capable of covering the frequency range up to Ku-band and realizes five beams directed at 0(degrees), +/- 20(degrees), and +/- 40(degrees) by 4 input channels. Experimental measurements demonstrate good agreement with designed parameters, validating the compatibility and feasibility of this beamformer for large-scale antenna arrays in radar and wireless communications systems.