Discrete-Time Network and State Equation Methods Applied to Computational Electromagnetics

The representation of electromagnetic structures by lumped element circuits is revisited. Network models can be established by a subsequent application of system identification and circuit synthesis methods to data obtained by numerical simulation or from measurement. Network models provide a compact description of electromagnetic structures and can contribute significantly to the formulation of electromagnetic field problems and their efficient solution. On the field level network methods are introduced by segmentation of the electromagnetic structures and application of the field form of Tellegen’s theorem. Methods for synthesis of lumped element models for lossless as well as lossy linear reciprocal multiports and for radiating structures are discussed. The state equation method as a general framework for lumped element network description is presented. Discrete time representations on the basis of Richards transformation and wave digital filter formulation are introduced.