Ultra wideband electromagnetic field coupling to instrumented electrically initiated device's (EIDs)

Ultra wideband (UWB) electromagnetic field (EMF) generation from portable sources has increased the threat of intentional EMI attacks on the civil and defense infrastructure. Various types of EIDs are used in a typical airborne system for applications like stage separation, firing of propulsion systems and triggering of warheads etc. The EIDs, potentially can be triggered when operating in an electromagnetic environment in general and in specific the threat is higher when operating in continuous wave fields, which is otherwise known as hazards of electromagnetic radiation to ordnance (HERO). Presently, the HERO safe certification for continuous wave field is being done to comply with MIL-STD-464 standards. However, the HERO problem for the transient fields from UWB systems, is unknown. This paper studies the essential UWB field coupling to EIDs to ascertain the HERO requirements. In this paper the experimental studies of UWB EMF coupling to EIDs is presented. The energy content of the induced transients computed are compared with safety margin as specified in MIL-STD-464. The present study finds application in designing protection circuits on subjective basis for reducing the HERO threat.