> With time-varying signals, the return current follows the path of least reactance, which is also the path of least impedance. This means the return current pa

> With time-varying signals, the return current follows the path of least reactance, which is also the path of least impedance. This means the return current path in your PCB is determined entirely by the impedance of the circuit that carries the return current. I was also a bit surprised by this. But I do recall doing equations regarding capacitive and inductive reactance. In both cases there is a frequency-dependent effect which alters the shape of the waveform. It being frequency dependent, it disappears in the presence of DC (inductors becoming irrelevant and capacitors becoming nonconductive). So I can kind of see it. But not enough to turn it into a return-path-is-suprising type example.