Constitutive Parameters of a Metamaterial Slab Retrieved by the Phase Unwrapping Method.

The constitutive parameters of a metamaterial slab showing negative refractive index over the 9-12 GHz frequency range are unambiguously retrieved from complex scattering parameters upon using the phase unwrapping method. Such a technique relies on properly adding to the phase of the complex transmission coefficient a stepwise function constructed from critical frequencies at which the phase of the transmission coefficient reaches ∓ π. [ABSTRACT FROM AUTHOR]