The Influence of Shielding Enclosure on the Characteristics of Protection Devices Operating in Differential and Common Modes

In this work, we used quasi-static simulation to evaluate the influence of shielding enclosure on the attenuation coefficient and per-unit-length delays of devices protecting against ultra-wideband pulses. The protection devices were 6-and 8-conductor structures, each consisting of two transmission lines with inhomogeneous dielectric filling, combined into one structure. The simulation showed that increasing the distance between the shield walls and the 6-conductor structure resulted in the same attenuation coefficients as without the shield. Therefore, the shield should be kept as far away as possible to preserve the characteristics. In the 8-conductor structure, increasing the distance to the shield walls had a non-significant influence on the attenuation coefficient in the common and differential modes. This probably happened because the active conductors were placed in the central part (inside) of the structure cross-section. The per-unit-length mode delays in both structures were not influenced by changing distances to the walls.