Axisymmetric electromagnetic fields coupled to lossy media

A solution for transient axisymmetric electromagnetic fields coupled to lossy media is presented. The resulting model is an interface problem in which the continuation of electric and magnetic fields are the interface conditions. A potential function is defined to model the problem in the time domain. Appropriate boundary conditions are imposed on the artificial boundary to absorb the outgoing field. Finite-difference techniques are used to match the potential function explicitly in time. Numerical methods are validated with analytic solutions and then applied to solve more complicated interface problems. As an example, the field distribution excited by an insulated small loop between two finite cylinders of lossy material is calculated and presented.<>