Common mode coupling of 3D-FDTD and MTL methods for in-situ cable bundle modeling

The Finite Difference Time Domain (FDTD) method is widely used in EMC simulation of structures composed of complex conducting surfaces and volumes. In addition, the thin wire formalism provides to the FDTD method the ability to efficiently deal with complex wire network. In this paper, we propose a new full hybrid FDTD – MTL method to deal with cable bundles in their realistic environment, taking into account the complexity of the return current path by the FDTD method. The voltage reference of the cable cannot be equivalent between both methods: the in-cell FDTD coupling for the thin wire formalism and a classical reference ground plane into MTL method. Therefore, we introduce a new technique to do the reference change of the common mode in MTL method in order to let the FDTD method solve the common mode current in its complex structure modeling.