in layout, if decouple caps are under high speed signals which run at the speed of about 2G, will the caps attribute any noise to the high speed signals?
Genarally they can. Capacitors and power plate acts like R-L-C circuits, but with different resonant freq. At the point where this two characteristics are cut, you could have peaking. You can find this in Montrose book on this forum.
Genarally they can. Capacitors and power plate acts like R-L-C circuits, but with different resonant freq. At the point where this two characteristics are cut, you could have peaking. You can find this in Montrose book on this forum.
if the cap are under the signals, then the parasitic caps between the signals and the layer of decoupling capacitors will be greater than the that while cap not under the signals?