Efficient phase-only synthesis of contoured-beam patterns for very large reflectarrays

This article presents an efficient phase-only synthesis method applied to contoured-beam reflectarrays. The method, based on the intersection-approach concept, provides the phase distribution of the reflected field that best suits the required gain-pattern specifications. In order to avoid undesired local minima, several successive stages, in which the tapering on the reflectarray's edge is gradually increased, are carried out to reach a final suitable result. As an example of its capabilities, the coverage of Europe is successfully synthesized.