A stability analysis of a time marching scheme for the general surface electric field integral equation

We present a stability analysis of a mixed finite element approximation of the time dependent electric field integral equation which is used to compute the current induced on a perfect conductor by a transient electric field. The analysis shows that the solution has fast growing unstable modes that are due to a combination of the finite element basis functions and the integral quadrature rule. These modes cannot be removed by standard time averaging methods, but they can be eliminated by averaging in space appropriately. (C) 1998 IMACS/Elsevier Science B.V.