Application of the enlarged cell method (ECM) to EMI/EMC problems

Conductors play an important role in the EMI/EMC problem. However, the conventional finite-difference time-domain (FDTD) method is known to produce significant staircasing errors when applied to conductors. In the past few years, many researchers have been using conformal FDTD methods to reduce this staircasing error. As a side effect, however, the time step size in these conformal FDTD (CFDTD) methods often becomes more restrictive because of the reduced effective grid size near the conductor boundary. An enlarged cell method is applied to solve EMI/EMC problems. We show that the ECM is highly accurate compared to the conventional FDTD method, and is three times faster than the conformal FDTD method because the time step size in ECM remains the same as in the FDTD method. Large-scale EMI/EMC problems have been solved with the ECM on a PC.