Poles and residues of lossy and dispersive electromagnetic metamaterials

This paper proposes a system-based pole-residue approach to describe loss and dispersion in double-positive (DPS), epsilon-negative (ENG), and epsilon-near-zero (ENZ) isotropic metamaterials. The matrix pencil (MP) method extracts the poles and residues from the damped sinusoids of the singular expansion (SEM) of the impulse responses of the transmitted and reflected waves. The complex values of poles and residues serve as a basis for a computational tool to discriminate between lossless, lossy, and dispersive materials. The extracted poles and residues can also be used to classify the material under test as a DPS, an ENG, or an ENZ metamaterial. The proposed method delivers reliable results even with noisy transmission and reflection data.