Protection of Cables by Open-Metal Conduits

The performance of metal conduits for protection of cables is investigated. An open U-shaped conduit is chosen as a basic configuration. A number of wires inside represents the actual cables with their shields. This configuration is subjected to a plane-wave excitation to determine the induced currents and voltages, which represent the common-mode signals in the cable shield. The simulated and tested object is 1.5 m long, with a cross section of 9 × 9 cm². Results are presented for frequencies up to 1 GHz, some up to 5 GHz. Measurement and simulation results agree to within 6 dB.