Tapered Multi-Beam Arrays via an Optically Power-Efficient Photonic Architecture

A novel photonic beam-space beam-former concept is reviewed and an additional theory addressing precise sampling of desired beam locations for linear arrays is presented. A new, power efficient, method of apodizing an input array's beam pattern via a weighted distribution of the master feed laser to each RF-to-optical up-conversion stage behind the array elements is then presented along with results from several apodization experiments. The experimental results are shown to produce effective, low-sidelobe responses, while also reducing the required prime input power to the system until an artificial side-lobe floor is reached. The root cause of the side-lobe floor is discovered to be due to phase and amplitude errors introduced within the photonic components currently used. Finally, key findings and design considerations are presented with respect to the usage of photonic beam-space sampling on large arrays and several suggestions for performance improvement in future system designs are discussed.