Effective Parameters for Metamorphic Materials and Metamaterials Through a Resonant Inverse Scattering Approach

• Published in: IEEE transactions on microwave theory and techniques Vol. 55; no. 2; pp. 254 - 267
• Main Authors: Alexopoulos, N.G., Kyriazidou, C.A., Contopanagos, H.F.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-02-2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Circuit properties; Composite materials; Conducting materials; Cylinders; Dielectric constant; Diffraction, scattering, reflection; Effective permittivity; Electric, optical and optoelectronic circuits; Electromagnetic scattering; electromagnetic scattering inverse problems; Electronic circuits; Electronics; Exact sciences and technology; Frequency; Inverse problems; Magnetic materials; Magnetic permeability; Magnetic resonance; Materials; Metamaterials; Metamorphic; Optical scattering; Oscillators, resonators, synthetizers; Permeability; Permittivity; Photonic band gaps; R&D; Radiocommunications; Radiowave propagation; reconfigurable architectures; Research & development; Telecommunications; Telecommunications and information theory; Performance evaluation; Left handed material; Predictor; Refraction index; permeability; Composite material; Resonance scattering; Frequency band; reconfigurable architectures; Effective permittivity; Electromagnetic field; Permittivity; Electromagnetic wave scattering; Optical path; electromagnetic scattering inverse problems; Absorbent material; Multiple layer; Dispersive wave; Amplifier; Wave impedance; Response function; Complex impedance; Electromagnetic wave propagation; Ring resonator; Photonic crystal; Interconnection; Integrated circuit; Passband; High frequency; Scattering matrix; Metamaterial; Simulator
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2006.890074

We present an inverse scattering approach for the bulk electromagnetic characterization of composite materials, based on a prior proof that artificial metallo-dielectric photonic crystals can be described by effective highly resonant response functions in a wide frequency range, including several passbands/bandgaps. The method becomes complete and unambiguous at high frequencies by employing the analytic continuation of the optical path length and a consistency criterion to ascertain the physical meaning of the extracted effective parameters. It may also be used as a fast simulator or as a measurement-based predictor of the performance of multilayered structures using the scattering matrix (simulated or measured) of a single monolayer of that material. The approach is applied for the characterization of metamorphic materials, which are recently introduced artificial structures that exhibit distinct macroscopic states of behavior as far as the reflected electromagnetic field is concerned. According to interconnect topologies of their scatterers, they appear, at a single frequency, as electric conductors, absorbers, amplifiers, and passive or active magnetic conductors. Detailed evaluations are given of the complex dispersive wave impedance, refractive index, and permittivity and permeability functions for each metamorphic state of a specific three-state metamorphic material. It is found that, as a rule, the electric and magnetic wall states are related to resonant permittivity and permeability values, respectively. Furthermore, the analysis reveals broad regions with negative values of permittivity or permeability. Both resonant and negative values of epsiv eff , mu eff occur within bandgaps or at band-edges. Finally, the approach is applied to the negative refractive index metamaterial composed of a cylinder and two split-ring resonators, which reveals the existence of a high-frequency band with negative group velocity