Bandwidth Improvement of Reflectarray Cells Using Variable Rotation Technique at Two Frequencies for Dual Circular Polarization

The bandwidth behavior has been studied and improved for a reflectarray cell formed by two symmetric arcs and dipoles printed on two layers, which uses Variable Rotation Technique at two frequencies for dual circular polarization. First, the appropriate thickness of the dielectric layers have been selected to improve the bandwidth. Then, an optimization routine has been applied to minimize the phase errors in a frequency band from 29.25-29.75 GHz. As a result of this optimization, the phase errors have been drastically reduced from ± 40 to ± 3 degree.