The stopband characteristics of an electromagnetic bandgap structure in a printed circuit board may be preserved by selectively forming slots in an additional conductive layer of the printed circuit board. For example, an electromagnetic bandgap structure may include a layer with a continuous conductive region and another layer with a periodically patterned region having a plurality of spaced-apart patches interconnected by branches. Additional conductive layers may be included within the printed circuit board without neutralizing the bandgap by forming slots in the conductive layers in general alignment with spaces between the patches.