Determination of combined cable shield and interstitial foil impedance for IWS harness

A SPICE model of the foils and overbraiding of an integrated wiring system (IWS) harness is created to characterize their combined impedance as a function of frequency. Comparison of predicted values of impedance to measured data for a modeled cable harness is accomplished, in which fair agreement is seen to exist. A straightforward empirical adjustment is then made to the SPICE model, which results in bringing the model-predicted values into very close agreement with the measured data. Possible reasons for initial model-predicted value disagreement with empirical data are discussed, and form the basis for future research.