Modeling and reduction of crosstalk on coupled microstrip line structures and multichip modules: An FDTD approach

Abstract

The finite difference time domain modeling technique is used to model the near end and far end crosstalk on coupled microstrip structures used in multichip modules. The lines are terminated in lumped resistors which closely, but not exactly, match the lines. One line is excited by a Gaussian voltage pulse produced by a Thévenin equivalent voltage source. It is shown that adding dielectric strips in the substrate below the conducting lines will reduce the peak crosstalk by as much as 80%. Eight different configurations are modeled consisting of dielectric strips with different dielectric constant combinations. All configurations are modeled with and without a metal case in order to make sure that the crosstalk reduction persists when the structure is enclosed in a metallic enclosure (this would be the case for multichip modules). The results show that using dielectric strips with the smallest possible dielectric constant reduces crosstalk the most. © 1996 John Wiley & Sons, Inc.