I'm routing LVDS and I wonder how much gap should I consider in between different pairs to not have any cross talk issue? (frequency=1 GHz)
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\$\begingroup\$ What crosstalk margin is acceptable? What is dielectric height above ground plane? \$\endgroup\$– Tim WilliamsCommented Apr 5 at 12:12
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I routed LVDS before, but for ~200MHz and had somehow good results with the TI rule of thumb. I find it reasonable to some extend, but like mentioned before, there are much more to consider about crosstalk than the spacing between the differential lines:
"To minimize crosstalk in high-speed interface implementations, the spacing between the signal pairs must be a minimum of 5 times the width of the trace. This spacing is referred to as the 5W rule. A PCB design with a calculated trace width of 6 mils requires a minimum of 30 mils spacing between high-speed differential pairs"
Source: High-Speed Interface Layout Guidelines
One more thing about routing high-speed lines in Altium:
In the rules, you most likely defined the length (minimum and maximum length of the net class) and matched length (group matched length & within differential pair length).
But this won't be enough in your case. You have to define a Clearance too. Something like this:
