Analyzing frequency selective surface with plane wave approach and the method of moments

In order to quickly analyze frequency selective surface (FSS), that conception of mutual admittance exist within FSS unit is introduced according to the antenna array theory. Then, the relationship between the FSS unit can be described by the mutual admittance equation which is slow convergence. With the assumptions that the FSS is infinite, the equation can be simplified by Floquet theorem, and then it can be solved by the method of moments (MoM). Meanwhile, some parameters of the equation must be simplified with the plane wave approach, which greatly reduced computational time. Some multiple FSS and multi-resonance FSS is analyzed with these approaches, and corresponding calculated results conformed to the experiments. In addition, these approaches own properties of quick convergence and short computational time.