EMC ANALYSIS AND PREDICTION OF COMPLEX ELECTRONIC SYSTEMS

A methodology is presented to study the interaction of electromagnetic disturbances with complex systems represented as networks of transmis sion lines. The systems are separated into distributed and lumped part s: a clear distinction is made between circuits of discrete lumped, li near, passive or active components that represent loads or interconnec tion blocks, and connecting wires that are treated as multi-conductor transmission lines. The telegrapher's differential equations represent a widely accepted model for wire bundles, buses or lines of common us e in electrical and electronic circuitry. Coupling with external inter fering disturbances is rigorously evaluated, and equivalent distribute d sources are introduced along the lines. Each subsystem is viewed as a multi-port component and is characterized in terms of a multi-port m atrix. This is a natural choice for the distributed element sections a nd it is also well suited for lumped circuits. The key element of this formulation is the definition of a correspondance matrix that account s for the topology of the connections between sections and blocks. The solution of the system equations describes the influence of a disturb ance in virtually any section of the network. The potential of this me thod to display either the frequency or the time response at different places inside a complex system is assessed.