IMPEDANCE BOUNDARY-CONDITIONS FOR TRANSIENT SCATTERING PROBLEMS

The approximate boundary conditions for the tangential component of th e electric field and normal component of the magnetic field on the sur face of a homogeneous body of finite conductivity (conductor or lossy dielectric) are derived for transient incident electromagnetic field, Scale factors for basic variables are introduced in such a way, that a small parameter, proportional to the ratio of the penetration depth a nd body's characteristic size, appears in the dimensionless Maxwell's equations for the conducting region and then the perturbation method i s used, The use of the boundary conditions together with space-time do main surface integral equations for electric and magnetic fields is pr oposed, A numerical example is included to illustrate the theory.