EFFICIENT IMPLEMENTATION ISSUES OF FINITE-DIFFERENCE TIME-DOMAIN CODES FOR MAXWELL EQUATIONS

The computer implementation of time-domain finite difference methods f or the solution of Maxwell's equations is considered. As the basis of this analysis, Maxwell's equations are expressed as a system of hyperb olic conservation laws. It is shown that, in this form, all the well-k nown differencing schemes can be easily expressed, thus increasing the applicability of the implementation issues to be discussed. Practical issues, such as computational efficiency and memory requirements, are discussed for the implementation of the finite difference schemes. Ad vanced programming techniques in the C language are used to implement the finite difference schemes discussed. The example of the penetratio n of electromagnetic energy through a shield with a thick gap is used to check the performance of the methods. It is shown that, for cases w here the disturbance remains localized in the computational mesh, thes e techniques result in memory and CPU time savings.