Signal transmission cable and method for making same

A signal transmission cable, comprising: a dielectric core extending along the length of the cable, the first electrically conductive layer laminated on one surface of the dielectric core, the dielectric core layer on the other surface of the second conductive layer are stacked, covering the first core layer and the dielectric, insulating the second conductive layer. The dielectric core and the first and second conductive layers, each having the same width. First and second conductive layers, each having the same thickness. The insulator is covered with a shielding layer, the shielding layer is covered with a sheath. Here, the first and second conductive layer constitute a pair of differential signal lines.