s a grid, using wide traces, on the signal layers. two added advantages of this configuration are that; (1) the two ground planes produce a much lower ground impedance and hence less common-mode cable radiation, and (2) the two ground planes can be stitched together around the periphery of the board to enclose all the signal traces in a faraday cage. from an emc point of view this configuration, if properly done, is the best stack-up possible with a four-layer pcb. now we have satisfied objectives, (