Eigenmodes of electrical components and their relation to equivalent electrical circuits

Physical equivalent electrical circuits facilitate root-cause analysis of resonance phenomena in electromagnetic components. We extend an existing formalism for the generation of physical equivalent circuits by linking the resonant behaviour of the equivalent circuit with 3D electromagnetic eigenmodes of the component. We define a figure of merit, which we call quality, describing the frequency range of validity and the accuracy of equivalent circuit descriptions of 3D components. We validate our approach by analyzing practical examples.