Error factors in transmission line analysis with 3-dimensional electromagnetic field simulations

In this work, the accuracy of FDTD simulation by the comparison of S-parameters, which are obtained by FDTD method and experimental measurement in the analysis of the printed circuit boards with simple structured signal line. In comparison of S-parameters of signal lines, the disparity occurred from cell size is regarded as the mismatch of the characteristic impedance of the modeled signal lines. An attempt is made to decide the adequate cell size by estimation of the characteristic impedance based on finite difference method (FDM). In addition, an efficient technique to compensate the characteristic impedance is described. It is expected that this study is useful for the verification of signal integrity.