Optically controlled phased array transmitter with a controllable main lobe and null.

Phased array transmitters often operate in contested electromagnetic environments. To achieve secure transmission and low probability of intercept operation, flexible beam control and generating a null to reduce radiation toward undesired directions are critical. In this work, a wideband optically controlled phased-array (OCPA) transmitter with flexible and independent control of the main lobe and null from a system control perspective is proposed. The proposed system integrates a spatial filter module consisting of an optical true-time delay network and balanced photodetectors. Simulation results for a 16-element OCPA based on the proposed architecture demonstrate that the main lobe and null can be scanned over a range of at least ±40° while maintaining a null depth greater than 50 dB. A proof-of-concept experiment is further carried out using a 5-element OCPA transmitter. The results show that the main lobe and null can be independently steered, with a null depth exceeding 50 dB.