In an electronic device having a compact form factor, a space-saving harness using bundled or ribbonized strands of micro-coaxial (micro-coax) cable may be utilized to provide signal and/or power interconnects between EMI-generating peripheral components and other components in the device such as those populated on circuit boards. Discrete wires are included in the harness to provide shielding to adjacent micro-coax conductors which may carry high speed signals such as MIPI (Mobile Industry Processor Interface) differential signal pairs and provide power and ground return paths. The discrete wires are subjected to fabrication processes during assembly of the micro-coax harness so that their outer diameters substantially match that of components in the micro-coax cable to thereby facilitate connectorization or termination to the circuit boards and/or other components in the device. The matching outer diameters can also provide a consistent pitch that may facilitate space-saving geometries for the harness, connector, and/or terminations.