An Efficient Field-Wire-Circuit Co-Simulation for Twisted-Wire Pairs in Complex Environment

In this paper, the terminal responses of twisted-wire pairs (TWPs) in complex platforms are obtained using field-wire-circuit co-simulation approach for multiscale electromagnetic analysis. The proposed method mainly combines the three-dimensional (3D) full-wave conformal finite-difference time-domain (CFDTD) method, the one-dimensional (1D) FDTD scheme for transmission line equations, and the state variable method for arbitrary terminals. First, the 3D full-wave FDTD combined with metallic conformal method is employed to compute the electromagnetic fields in PEC shielding cavities or automotive environments, where the magnetic-field updating equations on edge grids adjacent to metallic boundaries are modified. Then, a high-precision interpolation algorithm is used to obtain the electric-field components required for constructing the equivalent distributed sources along the TWPs, while the cables are not explicitly included in the full-wave simulation. Last, 1D FDTD method is applied to calculate the voltages and currents along the TWPs, and the terminal responses are solved together with the state variable representation of the terminal circuits. The proposed hybrid FDTD method naturally integrates the interactions among electromagnetic fields, cables, and terminal circuits. Numerical examples demonstrate that the results obtained by the proposed approach agree well with those from 3D full-wave simulations and CST Cable Studio co-simulation, confirming the accuracy and reliability of the proposed method. Moreover, the proposed hybrid method can apply larger mesh size to correctly calculate the terminal response of the TWPs, and the simulation time is greatly reduced.