Suppression of EM coupling spikes by line-shaping in high-speed coupled lines

A line-shaping method in coupled data bus lines is demonstrated for suppressing the coupling spikes. Considering the fact that there are infinite number of possibilities for choosing coupled conductor line profiles, it is logical to ask if there is a profile which is best to suppress the crosstalk for a given physical/geometrical PCB configuration and packing density. In this paper, the unknown conductor profile terminated with arbitrary loads in the integrated data bus is constructed from the inverse transform of the prescribed input reflection spectra by introducing 1-D reconstruction technique in the inverse scattering problem. The prescription is carried out through a special optimization process to enable the crosstalk peaks to be suppressed maintaining reasonable transmitted signal integrity without altering center-to-center distance between the nearest two conductor lines and circuitry position layout beforehand. The transient analysis is also simplified. This study enables the inherent full potential of nonuniform line to be derived for the best crosstalk handling.