Electromagnetic Topology Analysis of Ex- Ternal Pulses Interaction with Shielded Ca- Bles Using Spice Models

Simulations based on electromagnetic topology (EMT) have been carried out to analyze an external electromagnetic pulse interaction with a shielded coaxial cable linking two systems together. The proposed EMT approach, combined with the SPICE model of the shielded cable, can be applied in the transient simulation directly and used for the electromagnetic interference analysis of systems including nonlinear devices. The effects of the outer terminators, cable length, and connection of the voltage limiter on the induced voltages at the systems are studied by using the proposed EMT approach. It has been found that adding a resistance between the system’s shielding enclosure and the ground can effectively reduce the coupling through the shielded cable. The cable length affects the pulse-widths rather than the magnitudes of the induced voltages. The results also show that the voltage limiter can reduce the induced voltages but at the same time result in mismatch at the source or load.