Abstract: An improved flexible cable construction is provided which includes two layers of conductor traces arranged alternately with three layers of dielectric material in a flattened configuration between ground plane outside metal surfaces. Each of the conductor layers includes alternating signal traces and ground traces. In an exemplary embodiment, vias are arranged in first and second planes through the cable. Longitudinal vias maintain the potential of ground planes at the same level as well as improving shielding effectiveness along an edge or thickness cross-section of the cable. Transverse vias are implemented to minimize antenna effects due to large openings at the point of cable entry into a sheet metal box containing high frequency electronics.