Hi Mohammad,

For single element design you draw a single resonator on ground-plane backed substrate inside an air box  (at least lambda/4 taller than structure) and add master/slave boundaries to sides of air box and Floquet ports to top/bottom (no need for bottom if ground-plane backed). When drawing resonator you can add variables to the dimensions and then run the parametric modeler to vary those variables. This will help you determine your resonator pattern for your reflectarray. Once you have your pattern, draw a 10×lambda by 10×lambda model of the reflectarray, encase in air box with lamdba/4 gap between edges and reflectarray. Assign pml boundaries to all edges of the air box and excite with a plane wave. With this you can simulate the rcs to determine the scattering direction of your reflectarray.

thanks richard