Abstract: A printed circuit board that includes conductive layers separated by insulation layers of dielectric material, at least one conductive layer being patterned and having at least one signal line embedded in an insulation material, whereby a conductive ground plan layer, separated by the insulation material and lying in a predetermined distance (d) from the at least one signal line includes a ground plane area associated to and extending along the at least one signal line, the conductive layer associated to and extending along the at least one signal line is provided with openings therein. Preferably the openings are spaces between conducting stripes, extending, seen from above, across the at least one signal line, the conducting stripes being integrally connected with the conductive remainder of the conductive layer.