A Rigorous Approach to Designing Reflectarrays

A new approach for the rigorous design of reflectarray antennas is presented. Traditionally, reflectarray antennas are designed assuming local periodicity in which the mutual coupling is modeled as though each element is embedded in an infinite array of identical elements. This allows the fields to be expanded in terms of a Floquet series expansion. The design approach is approximate since reflectarrays are in fact aperiodic. Here, we present a new design approach which avoids any local periodicity assumption. Each element is modeled as a distinct element, and coupling calculated for the true array. Thus, the approach is rigorous. Simulation results are presented that verify the design method.