Can infinitely-wide power planes be specified in CZ2D?
No, but planes can be made as wide as necessary within reason. Very wide planes require additional unknowns and thus increase run time and could result in a loss of accuracy. Given a signal line h units above a ground plane, the general guideline is that planes should extend at least a factor five to ten times h beyond the outermost signal lines. For signal lines that both lie between power planes and are widely separated with respect to distance between the planes, the coupling values may be be very small (for example, 1 part in one million) and may not be very accurately calculated (but since they are so small, the error may not matter).
