ABSTRACT

The models we used till now assumed that the electromagnetic parameters σ, μ, and ε are scalar constants. In this section, we examine the circumstances under which the electromagnetic parameters are not scalar constants. In particular, we study the frequency dependence of the dielectric constant. In Section 8.1, we £rst study the interaction of an external electric £eld with a dielectric material by considering a volume of electric dipoles in free space. In Section 8.2, we study the frequency dependence of a dielectric material by considering a mechanical equivalent of an atom in a dielectric.