Premium
Vertically polarized waves in inhomogeneous media with critical coupling regions, energy conservation, and reciprocity relationships
Author(s) -
Bahar E.,
Agrawal B. S.
Publication year - 1976
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs011i011p00885
Subject(s) - wkb approximation , reciprocity (cultural anthropology) , physics , permittivity , reflection coefficient , electromagnetic radiation , electromagnetic field , transmission coefficient , wave propagation , electrical impedance , computational physics , optics , mathematical analysis , quantum electrodynamics , classical mechanics , dielectric , transmission (telecommunications) , quantum mechanics , mathematics , telecommunications , psychology , social psychology , computer science
Using a generalized WKB approach rigorous full wave solutions are derived for the electromagnetic fields for vertically polarized waves propagating through inhomogeneous dielectric media with critical coupling regions. Both the real and imaginary parts of the permittivity profile are assumed to vary in the horizontally stratified media. The generalized WKB solutions are consistent with energy conservation and reciprocity relationships in electromagnetic theory. The reflection and transmission coefficients and the related characteristic surface impedance for inhomogeneous layers of finite thickness are computed as functions of the transverse wave number for several permittivity profiles. Excitation of propagating and evanescent waves are considered. For the trapped waveguide modes of the inhomogeneous layer the reciprocal of the reflection coefficient vanishes and the layer is characterized by a surface impedance. Some special permittivity profiles for which closed form analytic solutions of the electromagnetic fields are known are also considered. Computations derived from these closed form solutions are shown to be in good agreement with computations based on the generalized WKB solutions.