Design of dual-reflectarray antenna for beam scanning

As a first step to evaluate the antenna performances considering the real effect of the reflectarray elements, the reflectarray subreflector has been designed by adjusting the lengths of the lines for each polarization to provide the required phase distribution associated to each scan angle. Then, the required line lengths should be realized by MEMS switches in the real implementation. However, the effect of the MEMS devices has been neglected in the present work, being the antenna analyzed assuming the reflectarray elements with the appropriate line lengths to provide the required phasing on the subreflector. This analysis includes the variation with frequency of the reflectarray elements and provides a preliminary estimation of the antenna performances. Considering the sub-reflectarray designed for 5° beam scan at 12 GHz, the antenna has been analyzed at other frequencies (10.7 and 14 GHz). Fig. 4 shows the radiation patterns in the principal planes at 10.7 GHz and at 12 GHz with no distortion in azimuth and very little distortion in elevation. These preliminary results illustrate the beam scanning capabilities of the proposed dual-reflectarray antenna.