Using the Maxwell grid equations to solve large problems

The capabilities of a set of finite-difference codes, based on the finite-integration technique (FIT), for solving Maxwell´s equations have been examined. Each of the Maxwell equations is separately discretized to produce an equivalent matrix equation. In this way, problems from a very broad area of physics and engineering can be solved by a method which not only produces unique, physical solutions, but in which the divergence equations are also satisfied. With only 60-204 bytes per mesh cell and six unknowns per cell, it is possible to calculate very large problems with up to 12 million unknowns on a modern workstation with a 128-MB memory. To indicate the range and complexity of the problems which can be solved using this method, a series of large (approaching a million unknowns) problems is presented-in particular, in the frequency domain for both resonant and eddy current problems and in the time domain for the broadband calculation of filter structures