Electromagnetic Transmission Through Periodic Narrow Slit with a Finite Thickness

Abstract

Electromagnetic transmission characteristics through a periodic narrow slit is analyzed numerically based on the Method of Moments. A key idea is to directly solve the matrix of Method of Moments about a unit cell slit. This analysis represents equivalent aperture admittances of each side of the slit and an admittance matrix of the inner part of the unit cell slit. These admittances are important for understanding the Floquet theorem, extraordinary transmission and Fabry-Pérot resonance phenomena. This analysis converges very fast compared to the commercially available simulator and gives equivalent transmittance coefficients.