Design of Near-Field Synthesis Arrays Through Global Optimization

We provide a study of the relation between the near- and far-fields in antenna systems by working with a concrete design problem. The task of finding an antenna array capable of synthesizing a desired near-field distribution is tackled within the general framework of near-field theories recently proposed in literature. We use a genetic algorithm to search for a set of small antennas by working only with far-field data. It is shown, as predicted theoretically, that such information in the far zone are sufficient for reconstructing the entire near-field in the exterior region. We provide a set of examples demonstrating the procedure and validating the proposals. The methodology can be applied to arbitrary antennas and any desired near-field pattern, and we hope it will help automating design methods in the emerging research area of near-field array synthesis.