Analysis and design on EM wave absorption by stratified construction materials - a case of vertically incident wave

It is known that EM waves are largely absorbed at discrete frequencies, which we can call absorbing frequencies, when a plane wave is normally incident onto the surface of the stratified structure which consists of two low-loss construction materials. In this paper, an approximate analysis on the absorption will be given and a design formula and a design diagram for the structural parameters will be presented. Furthermore, formulae for the Q-factor concerned with the absorption and the change in the absorbing frequency due to the change of the effective dielectric constant of the composite construction material by the perturbation method will be derived.