Unlocking Complexity Using the ECA: The Equivalent Circuit Model as An Efficient and Physically Insightful Tool for Microwave Engineering

In the study of electromagnetic wave propagation and scattering, researchers have always faced the dichotomy of dealing directly with Maxwell's equations (and their complicated analytical/numerical solution methods) or trying to find a simplified model (usually in terms of an equivalent circuit) that can help provide some physical insight into the involved electromagnetic phenomena. The pursuit of analytical solutions for propagation, radiation, and scattering problems does not seem to be a task currently in much demand in microwave engineering, although it was only 20 years ago that many research papers on these topics included some sort of analytic derivations.