A computationally efficient hybrid FDTD method for solving field-to-wire coupling problems in shielded cables with junctions inside electrically large objects

Abstract

A computationally efficient hybrid Finite Difference Time Domain (FDTD) method is proposed in the paper to solve field-to-wire coupling problems in multi-conductor shielded cables with junctions inside electrically large objects. In the method, shielded cables illuminated by electromagnetic fields are represented by the external and internal transmission line models. The two models are coupled by a transfer impedance due to the shielding conductive layer. Furthermore, shielded cables' junctions are specially handled by applying three theorems in both external and internal transmission line models. Moreover, the transmission line models are then integrated into an in-house 3D FDTD solver, JEMS-FDTD, to efficiently model shielded cables with junctions inside electrically large objects. In the end, the proposed hybrid method is validated by assessing the induced effects of a three-conductor shielded cable with junctions inside a vehicle when the illumination is a plane wave excited by a strong Electromagnetic Pulse (EMP) and comparing the results with those obtained from the commercial software.