A Novel Phase Synthesis Approach for Wideband Reflectarray Design

This communication proposes a novel wideband phase synthesis approach, which is able to considerably increase the bandwidth of the reflectarray antenna independent of the element frequency behavior. Specifically, the reference phases at the Ku-band transmitting and receiving frequencies are optimized, simultaneously, to minimize the total phase error of the reflectarray. Simulation and experimental results of reflectarrays consisting of simple square-ring elements show that a 16.7% measured bandwidth within 1.5-dB gain variation can be achieved by a single-layer design with a thin substrate. The proposed approach is applicable to general reflectarray elements and the phase synthesis process is easy-to-implement compared with other conventional wideband reflectarray designs.