NONLINEAR ELECTROMAGNETIC SCATTERING BY A POLYCONDUCTOR SLAB.

A solution of the nonlinear electrothermal problem of the scattering of plane electromagnetic waves normally incident on a polyconductor slab with a metal substrate is presented. Since the electrical conductivity of the slab is a nonlinear function of the temperature profile, and hence the power absorbed at every point in the slab, the formation for the electric field and temperature distribution in the slab leads to a pair of coupled nonlinear second order differential equations which are solved partially analytically by the W. K. B. method and partially numerically by the finite difference numerical method. The variations of the reflection coefficient, the surface impedance and surface temperature with frequency and incident electric field, as well as the resulting profiles of the electric field, conductivity and temperature inside the slab are presented in graphical form, discussed and analyzed. These results suggest certain practical applications which are also described.