Direct calculation of permeability and permittivity for a left-handed metamaterial
TL;DR: In this article, an electromagnetic metamaterial was fabricated and demonstrated to exhibit a "left-handed" (LH) propagation band at microwave frequencies, a situation never observed in naturally occurring materials or composites.
Abstract: Recently, an electromagnetic metamaterial was fabricated and demonstrated to exhibit a “left-handed” (LH) propagation band at microwave frequencies. A LH metamaterial is one characterized by material constants—the permeability and permittivity—which are simultaneously negative, a situation never observed in naturally occurring materials or composites. While the presence of the propagation band was shown to be an inherent demonstration of left handedness, actual numerical values for the material constants were not obtained. In the present work, using appropriate averages to define the macroscopic fields, we extract quantitative values for the effective permeability and permittivity from finite-difference simulations using three different approaches.
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01 Jan 2012
TL;DR: In this article, a TM mode analysis in a metamaterial based dielectric waveguide is proposed and introduced, and the dispersion properties are focussed on the fundamental properties of bound, surface and leaky modes of metammaterial based waveguide.
Abstract: A TM mode analysis in a metamaterial based dielectric waveguide is proposed and introduced. Rigorously derived from Maxwell's equations, the dispersion properties are focussed on the fundamental properties of bound, surface and leaky modes of metamaterial based dielectric waveguide. Comparing with the conventional right handed material based waveguide, typical backward wave characteristic of volume and surface wave modes are found from the distribution of Poynting power to the transverse direction of waveguide.
01 Jan 2018
TL;DR: In this paper, a characterization of a metamaterial structure in time and frequency domain was made through simulations and experiments, which consists in a series of edge-side coupled Split Ring Resonators (SRRs) in a below cutoff waveguide.
Abstract: Interest in Metamaterials has been rising drastically in the recent years as they have been used in several optical and RF applications, from antennas to perfect lenses and pulsed power devices. Nevertheless, the time-behavior of metamaterials remains opaque and poorly understood. In this research work, characterization of a metamaterial structure in time and frequency-domain was made through simulations and experiments. The structure consists in a series of edge-side coupled Split Ring Resonators (SRRs) in a below cutoff waveguide. A linear time invariant model of distributed elements has been elaborated as well in an attempt to approach the structure’s behavior. The comparison between simulations, measurements and model demonstrated agreement and confirmed qualitatively behavior that was previously observed in similar structures. The linear model constitutes a basis for further studies to understand metamaterial behavior or for the design of metamaterial with controlled characteristics.
Cites background from "Direct calculation of permeability ..."
...In 2000, Smith [2] formulated expressions of permeability and 3 permittivity of a Left-Handed medium....
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...In 2000, Smith [2] formulated expressions of permeability and...
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...Following that in 2002, Smith et al. [4] confirmed the antiparallel group and phase velocity properties of LHM by studying modulated waves at the interface between a positive and negative refractive index material....
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04 Dec 2005
TL;DR: In this paper, an advanced method was introduced to determine the negative indices of the composite meta-material, which was a slab of finite thickness simulated by FDTD and the phase of the total field was extracted with an optimized phase extraction technique.
Abstract: An advanced method was introduced to determine the negative indices of the composite meta-material. The macroscopic configuration of meta-material simulated in FDTD was a slab of finite thickness. A genuine plane wave normally incident on the slab was simulated by FDTD and the phase of the total field was extracted with an optimized phase extraction technique. The phase of the total field was verified to vary monotonously along the center of the slab. According to this property, the wavelength, the phase velocity and refraction index of the electromagnetic wave in the meta-material were readily determined. As comparison to our method, the conventional method to determine refraction index with Snell's law was also performed. The results of our method and the conventional method are in good agreement. But our novel method cut down the computational domain more than 30 times and greatly save the computation time.
TL;DR: In this paper , a stacked wideband metamaterial is proposed for a robust and compact dual-band wireless power transfer (WPT) system, which employs split ring resonator (SRR) unit cells loaded by non-uniform capacitors.
Abstract: A novel stacked wideband metamaterial is proposed for a robust and compact dual-band wireless power transfer (WPT) system. The proposed metamaterial employs split ring resonator (SRR) unit cells loaded by non-uniform capacitors. First, two types of unit cells that exhibit two resonance frequencies are analyzed. The results show that it can only improve the coupling between the transmitter (Tx) and the receiver (Rx) at the single band. Then each unit cell is sandwiched with each other, and a hybrid unit cell that indicates three resonance frequencies is finally proposed. The hybrid SRR exhibits near-zero permeability within the wide frequency range of interest. Therefore, the proposed metamaterial is effective at both bands simultaneously. The system was fabricated and tested, including a compact dual-band WPT system. The size of the Tx (Rx) and the metamaterial are 15 × 15 mm 2 and 20 × 20 mm 2 , respectively. The measured figure of merits (FOMs) are 0.92 at 390 MHz and 0.85 at 770 MHz, respectively, at a power transfer distance of 20 mm, which is a significant improvement over recently proposed dual-band WPT systems with metamaterials.
TL;DR: In this paper, a metamaterial composed of cut wire pairs (CWP) separated by dielectric substrate on the basis of circuit theory has been theoretically predicted in order to obtain the equivalent electromagnetic parameters (permittivity and permeability).
Abstract: Retrieving the equivalent electromagnetic parameters (permittivity and permeability) plays an important role in the research and application of metamaterials. Frequency dispersion of magnetic permeability has been theoretically predicted in a metamaterial composed of cut wire pairs (CWP) separated by dielectric substrate on the basis of circuit theory. Magnetic resonance resulting from antiparallel currents between the CWP is observed at the frequency of minimum reflection loss (corresponding to absorption peak) and effective resonator size can be determined. Having calculated the circuit parameters (inductance L, capacitance C) and resonance frequency from CWP dimension, the frequency dispersion of permeability of Lorentz like magnetic response can be predicted. The simulated resonance frequency and permeability spectra can be explained well on the basis of the circuit theory of an RLC resonator.
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10,495 citations
TL;DR: In this paper, it was shown that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu/sub eff/, which can be tuned to values not accessible in naturally occurring materials.
Abstract: We show that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu//sub eff/, which can be tuned to values not accessible in naturally occurring materials, including large imaginary components of /spl mu//sub eff/. The microstructure is on a scale much less than the wavelength of radiation, is not resolved by incident microwaves, and uses a very low density of metal so that structures can be extremely lightweight. Most of the structures are resonant due to internal capacitance and inductance, and resonant enhancement combined with compression of electrical energy into a very small volume greatly enhances the energy density at critical locations in the structure, easily by factors of a million and possibly by much more. Weakly nonlinear materials placed at these critical locations will show greatly enhanced effects raising the possibility of manufacturing active structures whose properties can be switched at will between many states.
8,135 citations
TL;DR: A composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with simultaneously negative values of effective permeability and permittivity varepsilon(eff)(omega).
Abstract: We demonstrate a composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with
8,057 citations
TL;DR: In this article, an effective description for a metalodielectric photonic bandgap (PBG) material was developed for a semi-infinite and slab observables.
Abstract: An effective description is developed for a metalodielectric photonic bandgap (PBG) material far beyond the quasi-static limit of traditional effective-medium theories. An analytic approach, recently presented by the authors, is further advanced to provide the complete effective permittivity and permeability functions. Reflection and transmission coefficients are presented for both TM and TE oblique plane-wave incidence, based on the determination of the equivalent impedance for each lattice plane in the crystal and the transfer-matrix method for reconstructing the effect of successive lattice planes. An analysis of the semi-infinite and slab observables yields the anisotropic effective refractive index, effective permittivity, and effective permeability, thus completing the macroscopic description of the interaction of electromagnetic waves with the medium. Among the novel aspects of the analysis is the equivalence of our PBG system with a physically dispersive system at ultraviolet frequencies and the derivation and explanation of the development of high dispersive magnetization (permeability) for these media, independently of the microscopic magnetic properties of the metallic implants.
44 citations