Investigation of systems of densely periodic gratings with application to functional elements in the millimeter and submillimeter wavelength ranges

A theoretical study of the transmission of electromagnetic waves through a system consisting of three densely periodic gratings is presented. The Vladimirskii boundary conditions are used to derive expressions for the reflection and transmission coefficients of this system for arbitrary distances between the gratings and arbitrary orientation angles of their conductors. These expressions are used to calculate the electric characteristics of two functional elements: a reciprocal system of polarization-plane rotation and a variable attenuator. Calculations are found to agree well with experimental results.