Why return path in PCB is as significant as signal path with an example

[sushl]

Hi
It would be Helpful if anyone can provide an example of why return path is significant in PCB design.

Thanks and Regards
Sush

[KlausST]

Hi,

do an internet search for:
"return path discontinuities"
"stripline return path"
"high speed layout guidelines"
and so on

...and you will find lots of documents, descriptions, tutorials ...

like this:
www.ti.com/lit/an/scaa082a/scaa082a.pdf

Klaus

[marce]

Its important because its 50% of the signal...

[dick_freebird]

Nothing happens until you close the current loop.
That is "the path". Not just the part you think is
"signal". The "signal" trace should be signal and nothing
but (in a perfect world). The return, that's a shared
resource unless you make it likewise clean and single
purpose.

Like, you may take a limo to the prom, but you are
going home on public transportation. So watch where
you sit, because that tux has a cleaning deposit.