Optically Driven Ultrawideband Phased Array With an Optical Interleaving Feed Network

A novel optically driven ultrawideband phased array is presented. In the array, two coherent optical signals mixing at photodiodes produce RF signals that are tunable over an ultra-wide bandwidth. An optical interleaving feed network is used to drive the array, which is capable of mitigating phase drift due to acoustic vibration and maintaining phase fidelity. In addition, excess noises in the system are analyzed and found to be responsible for spurious beams. The excess noise can be suppressed by optimizing polarization states of optical signals in polarization-maintaining (PM) fibers. Accordingly, the sensitivity can be significantly increased. In the end, the concept is proven by demonstrating experimental results from a 1 × 2 array consisting of two wideband Vivaldi antennas.