Efficient numerical model to analyze the conformal capacitive frequency selective surfaces

A modified model is presented to simulate the electromagnetic properties of the conformal capacitive frequency selective surfaces (FSSs). By employing a duel set of quasi-orthogonal rooftop basis functions for the surface current distribution over the FSSs conducting surface, the conditioning of the system matrix is significantly improved without decreasing the solution accuracy or increasing the computational costs. Consequently, the iterative convergence rate is speeded up in comparison with the conventional rooftop-expanded scheme. Besides, without subdividing the narrow side of the conducting cells of the FSSs in the space discretization, the proposed model is also geometrical-adaptive and engineering-accordant, which results in a significant reduction of the number of unknowns. Numerical experiments demonstrate the satisfactory accuracy and much higher efficiency of the proposed scheme.