Semi analytical model for non-resonant layered frequency selective surfaces (FSS)

The proposed approach employs transmission line theory to model electromagnetic wave propagation through FSS comprising of non-resonant metal grids and patches. The equivalent reactance of the individual metal layers is initially estimated by minimizing the error between scattering parameters obtained from 3D full wave simulations and ABCD matrix of the free standing structure. With the knowledge of the individual metal layer's reactance, a simple analytical model is adopted to predict the frequency response of multi-layered FSS for different configurations without the need for 3D full wave simulations. Performance of this semi-analytical approach is studied for varying unit cell size, D (λ/5-λ15), metallization dimensions, and number of FSS layers in X-band (8-12 GHz). The frequency response of the semi-analytical model is in good agreement with 3D full wave simulations suggesting that the proposed approach is faster and simpler for design of multi-layered non-resonant FSS.