Numerical and experimental method for the analysis of radiation from two wire power lines in networking cables

The frequency response of thin metallic wires that are found in networking cables is an important parameter required for the EMC/EMI evaluation of associated devices. One of the popular numerical methods used for such studies is the finite difference time domain (FDTD) method. In the FDTD technique, the contour-path thin wire model, based on Faraday´s law, is widely used to simulate the effect of thin wires. This technique and its variants use perfect electric conductor (PEC) approximation for the wires and are not suitable to calculate the frequency response of thin power supply wires inside cables. This is due to the fact that the PEC approximation would result in an inaccurate estimation of the frequency response of such wires in the calculation of EMI. In this paper, we demonstrate the application of the surface impedance boundary condition (SIBC) along with the classical contour-path thin wire approximation in the FDTD method in order to provide improved reflection and transmission coefficients of thin wires that could be used for enhanced EMI prediction.