A Methodology for Assessing Interface Threats in Satellite Electronics from IEMP and Cable Direct Drive Excitations

By invoking a simple canonical model and concomitant closed form solution, a methodology is presented which permits an engineering approach to the problem of quantifying interface threats due to IEMP and cable direct drive induced in satellite cables. The methodology should provide a useful tool for performing trade studies to develop hardening requirements for satellite manufacturers which may be introduced early in the design cycle. The engineering model described in our paper is very simple. The cable of concern is treated as a transmission line relative to the cavity structure. The effect of the IEMP and cable direct drive on the cable is described as a set of distributed drivers for the defining transmission line equations. The distributed drivers are developed from the cavity fields and currents using first order perturbation theory. The conditions for validity of the transmission line/perturbation theory model normally hold for problems of interest to the satellite design community. The resulting transmission line equations derived from the model are solved and presented in terms of simplified, time domain, closed form, exact solutions for determining the interface threats resulting from both IEMP and cable direct drive responses. These results, which are defined in functional form as a finite sum of terms, are derived from transmission line theory and duality transformations and also feature the capability to address time phased photon excitations. The present model invokes the utilization of driving fields characteristic of small cavities, i. e.