Does the FFC package foil have no grounding, which is equivalent to adding a capacitor to the cable?
It should be equivalent to adding a return path to the high speed signal
If both ends are not grounded, it should be equivalent to the effect of adding an inductor (somewhat like the use of a magnetic ring).If there is a parasitic capacitor, it exists everywhere, but the size of the parasitic capacitance.
If the single ended ground is not connected, as you say, it is equivalent to adding a capacitor to the ground;
