High speed input/output connection interface element, cable assembly and interconnection system with reduced cross-talk

The present invention relates to a high speed input/output (I/O) connection interface element, to a cable assembly comprising such an interface element and to an interconnection system comprising such a cable assembly and a belonging jack connector for contacting the cable assembly. The I/O connection interface element comprises a substrate (102) carrying a plurality of electrically conductive leads (106), each of said conductive leads having an I/O transition interface to be connected to at least one I/O conductor. The electrically conductive leads comprise input leads and output leads which are arranged on opposing faces of said substrate, and wherein at least one electrically conductive ground plane layer (116) is arranged at least partially within said substrate, being electrically insulated from said plurality of conductive leads. At least one ground plane layer is provided with at least one clearance (118) in a region adjacent to the transition interface.