Specifying electromagnetic compatibility (EMC) is a crucial step in the performance evaluation of electrical and electronic systems. This paper describes a circuit formulation for the EMC assessment of large and complex systems.
The proposed method is based on breaking the actual structure down into an aggregation of multiport devices: lumped-parameter circuits and distributed-parameter multiports. The multiconductor transmission line (MTL) model is used for the description of signal propagation along system interconnects: uniform, twisted and shielded lines are considered. Accurate prediction models (including line losses and dispersion) are utilized for the quantitative evaluation of both intrasystem compatibility and susceptibility to radiated interference.
The description of the network topology makes use of the concept of an incidence matrix which is widely used in lumped-circuit theory. It is extended here to the more general case of distributed networks. The entire analysis is carried out in the frequency domain and a transient response is obtained by using inverse Fourier and Laplace transforms.
Noteworthy characteristics of the method can be seen in the simplicity and effectiveness of the prediction models and in the minimal effort required for system description. The proposed method is especially significant for complex systems, where the number of connecting structures can be quite large.