Phase-Only Optimization of Beam Efficiency for a Large Scanning Reflectarray

A fast and efficient method for synthesizing element excitations for very large reflectarrays is presented to be used on a Configurable Reflectarray for Electronic Wideband Scanning Radiometry (CREWSR). CREWSR is a tri-band scanning reflectarray that contains three lattices of antenna elements, each containing 120,000 to 480,000 elements. Applying the fast Fourier transform and the alternating projection method allows for an optimization algorithm that achieves phase-only synthesis, targeting side lobe levels to increase beam efficiency.