The common idea for a stripline is that the trace is sandwiched between two ground planes.
My question: is it the same, for the purpose of characteristic impedance, to have a ground plane or a power (VCC) plane? That is, would the stripline's characteristics be the same if I sandwich the trace between GND/GND, or between GND/VCC, or even VCC1/VCC2?
My instinct is that it should be the same, since for small-signal analysis VCC is the same as GND. And as I understand it, characteristic impedance aspects go with small-signal analysis. However, I'm not sure that this is the case. Plus, even if it is the case: are there any requirements on the geometry or decoupling for the power plane(s)?