Experimental analysis and circuit modeling of pulsed current injection in wire pairs

Pulsed current injection (PCI) allows testing the immunity of electric/electronics devices against fast and intense transient electromagnetic disturbances. This technique resorts to inductive couplers to directly inject noise currents into the harness entering the device under test (DUT). Although the characteristics of the stress waveform to be induced at the DUT input are assigned by the Standards, and set by calibration, the noise actually entering the DUT input ports may exhibit significant differences due to the frequency response of the injection device itself as well as specific setup arrangements. To investigate these influence factors, possibly compromising test significance, in this work a PCI test setup involving a wire-pair is setup and modeled in the SPICE environment. Measurements and simulations are exploited to put in evidence the effects that the presence of other wires (and their terminations) in the bundle play on the voltage waveform induced at the terminations of a specific wire. The results here presents are significant also in view of extending the analysis to more complex wiring configurations (currently ongoing), and in order to correlate the PCI technique with radiative immunity procedures foreseen by the Standards.