OPTICAL-FIBER GRATING-BASED BEAMFORMING NETWORK FOR MICROWAVE PHASED-ARRAYS

A new photonic-based beamforming network that can realize a large numb er of simultaneous and independent beams in a wide-band phased-array a ntenna, and which eliminates optical beat-noise interference is presen ted, It is based on discrete and chirped Bragg-grating true-time delay elements and photodetector arrays at each beam port, This achieves a highly parallel delay-processing structure for signal equalization and eliminates the fundamental optical beat-noise limitation to the reali zation of large array sizes, Results show a very substantial reduction in the number of interconnects required of 98.4 % for a 512-beam arra y and 99.2% for a 1024-beam array, in comparison to conventional beamf orming techniques.