Analysis of Reflectarray Antenna Elements Under Arbitrary Incident Angles and Polarizations Using Generalized Boundary Conditions

A novel analysis method for reflectarray antenna elements is proposed in this letter, which is derived from generalized boundary conditions. First, the effective surface susceptibilities of the patch layer are extracted from two sets of simulations of given incident angles and polarizations. Then, the effective surface impedances of reflectarray antenna elements are analytically computed for arbitrary incident angles and polarizations, from which the reflection coefficients can be readily obtained. The detailed analysis procedure is presented, and its effectiveness is validated through several representative examples of reflectarray antenna elements.