Full-Wave FDTD Analysis of UWB Pulses on Printed Coupled Lines

We have performed a comprehensive 3D FDTD transient analysis of EM pulses propagating on coupled printed lines with multilayer dielectric substrates and in complex 3D structures. The simulation results have revealed a wealth of new physical features, which are, to our best knowledge, seen for the first time. A comparative analysis of pulse propagation on coupled lines in a homogeneous medium, and on single and coupled lines with layered substrates has been used to elucidate the mechanisms of pulse distortion and crosstalk and to discriminate the effects of dispersion and coupling. It is demonstrated that the coupling to some extent compensates dispersion, thus reducing pulse distortion on source line and crosstalk. Complex line arrangements with pedestal substrates and additional conducting walls have been studied with the aim of reducing interference of the pulsed signals on closely spaced printed traces. Effects of the line topology and substrate parameters on the signal integrity and coupling are discussed in the paper