Crosstalk versus interline space in ultra high speed digital PCBs

In this paper, the behavior of the crosstalk versus the pulse-width of an ultra-high-speed digital signal in a closely spaced parallel coupled microstrip line is numerically characterized based on the spectral domain analysis (SDA). The results show that for a certain signal pulse width, the voltage amplitude of crosstalk does not decrease monotonically as the space between the microstrip lines increases.