Some Properties of the Electromagnetic Field in a Stratified Layer

摘要

In connection with the millimeter-wavelength radome design problem, a study was made of the field distribution in an inhomogeneous layer. By examining the poynting vector and two quadratic forms which are closely related to the energy density, some useful properties of the electromagnetic field are determined for a one-dimensionally stratified medium. New expressions are derived for the upper bounds on the moduli of the electric and magnetic field intensities in a medium in which the permittivity and the permeability may vary as a function of one of the rectangular coordinates. Several numerical examples are presented. Not only are these upper bounds simple to calculate, but also they yield more accurate and useful results than the previously available expressions. An estimate is developed for the error involved in the WKB approximation for the field distributions in an inhomogeneous layer, and a numerical example is included. (Author)