Scattering of Electromagnetic Waves on a Subwave Lattice of Square Strip Conductors

Simple formulas are obtained for calculating the scattering matrix of a plane electromagnetic wave incident normally on an infinite 2D lattice formed by square strip conductors and located at the interface of two dielectric media. For the first time, the vortex behavior of the electric field of the lattice was taken into account, which made it possible to repeatedly reduce the computation error at high frequencies. This is confirmed by the close agreement of the amplitude-frequency responses of the structure calculated by the formulas with the characteristics obtained by the numerical electrodynamic analysis of the 3D model when the lattice period is less than half the wavelength.