here we are providing power plane as reference.the return current flowing through the power plane will cause any problems.Hi,
An electrical signal needs a return path.
There is no signal that goes only from A to B, it also needs the return path back from B to A.
It is a loop.
And the return path is equally important as the signal path.
If a trace travels over an uncut GND plane, then the "return" current travels rather exactly back atbthe same location in the plane. Not much right or left.
If there is a cut in the GND plane ... under the trace...
Then the return current at this place of plane can not travel directly, it needs to use a different, longer path ... causing impedance jumps in the signal line, echoing, bad signal quality...