Efficient computational models of electromagnetic coupling through general tortuous-path, narrow-slot apertures into shielded systems

Electromagnetic coupling can adversely impact a multitude of applications. The primary coupling issues are electromagnetic compatibility and interference, either intentional or unintentional. The functionality of the systems involved, which typically consist of numerous subsystems operating concurrently, can be characterized in terms of their susceptibility, vulnerability and survivability in the electromagnetic environment in which they are expected to operate. Coupling through unforeseen apertures such as the tortuous-path, lapped seam depicted in the paper into conducting cavities containing multiple thin conducting elements is the major thrust of this work. To model realistic coupling problems, it is necessary to develop a model which includes a three-dimensional representation of the slot/cavity/wire configuration. Specifically, such a model should incorporate narrow slot apertures having depth, loss and gaskets, bolt loads, backed by arbitrarily-shaped cavities, filled with inhomogeneous, lossy dielectrics, and thin wires in arbitrary configurations. The widely varying scales in such a system provides a challenge to a numerical model in terms of both accuracy and efficiency. This is especially true in a development engineering environment in which the engineer typically has a desk-top workstation on which to perform an analysis.