Estimation of the interference coupling into cables within electrically large multiroom structures

[摘要] Communication cables are used to transfer data between components of asystem. As a part of the EMC analysis of complex systems, it is necessaryto determine which level of interference can be expected at the input ofconnected devices due to the coupling into the irradiated cable. Forelectrically large systems consisting of several rooms with cables connectingcomponents located in different rooms, an estimation of the coupleddisturbances inside cables using commercial field computation software isoften not feasible without several restrictions. In many cases, this isrelated to the non-availability of computing memory and processing powerneeded for the computation.

In this paper, we are going to show that,starting from a topological analysis of the entire system, weak couplingpaths within the system can be can be identified. By neglecting thesecoupling paths and using the transmission line approach, the original systemwill be simplified so that a simpler estimation is possible. Using theexample of a system which is composed of two rooms, multiple apertures, and anetwork cable located in both chambers, it is shown that an estimation of thecoupled disturbances due to external electromagnetic sources is feasible withthis approach. Starting from an incident electromagnetic field, we determinetransfer functions describing the coupling means (apertures, cables). Usingthese transfer functions and the knowledge of the weak coupling paths above,a decision is taken regarding the means for paths that can be neglectedduring the estimation. The estimation of the coupling into the cable is thenmade while taking only paths with strong coupling into account. The remainingpart of the wiring harness in areas with weak coupling is represented by itsinput impedance. A comparison with the original network shows a goodagreement.

[学科分类] 电子、光学、磁材料