Numerically Efficient Modeling of Frequency Selective Surfaces in Broad Frequency Range

Fast and accurate simulation of the electromagnetic field around frequency selective surfaces (FSSs) are needed for the design and optimization of devices based on the use of FSSs. The authors recently published a computationally efficient calculation method for the analysis of FSSs where the current distribution in the conducting parts are locally approximated by currents associated to electromagnetic waves propagating perpendicularly to the surface of the FSS. In this paper, an improved version of this method is presented. Here, in addition to the described assumption, local plane wave distribution of the current density is imposed also with respect to that surfaces being perpendicular to the surface of the FSS. By this modification, the error of the described calculations becomes very small in a very broad frequency range while the computational burden remains low, consequently the method can be advantageously applied for the solution of design and optimization problems.