An Innovative Inverse Source Approach for the Feasibility-Driven Design of Reflectarrays

The design of feasible surface currents in reflectarray antennas (RAs) is addressed. By exploiting the nonuniqueness of the associated inverse source problem, an innovative synthesis method is proposed to simultaneously match radiation requirements and constraints on the surface currents. First, the surface current of the RA is expressed as the linear combination of a “pre-image” term, which is computed with a truncated singular value decomposition of the RA radiation operator, and a suitable “null-space” component. A customized multi-agent global optimization is applied to set the latter. A set of numerical experiments, concerned with different RA apertures and radiation objectives, are presented to illustrate the features of the proposed approach as well as to assess its potentialities and current limitations.