Identification of Compact Equivalent Circuit Model for Metamaterial Structures

In this work, a simple and efficient circuit modeling of metamaterial structures, providing a compact circuit able to describe accurately the device over a large bandwidth of operation, is proposed. The equivalent circuit model is obtained by the identification process of the load in terms of shunt branches constituted by reactive elements that can be both positive and negative. The circuit model is validated by analyzing the split-ring resonator (SRR) structure. The presence of negative elements in the non-Foster load is transformed into positive reactive elements by converting the load from shunt into series. Unlike the T or $\Pi $ circuit models, using this approach a circuit model can be constructed directly from the scattering parameters and valid for any circuit topologies.