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TE guided modes at microwave frequencies in metal-left-handed material-ferrite waveguide structures are studied numerically. The effect of ferrite layer parameters on the dispersion properties of the waveguide structure is investigated in details. It is found that the modal index of the guided mode is negative as if the overall structure was left-handed material. A considerable effect of the gyromagnetic ferrite layer on the dispersion properties of the structure is observed. The power propagating in each layer is also evaluated. [ABSTRACT FROM AUTHOR]

Two new types of heterogeneous left‐handed materials (LHM) are presented in this article. By combining the split resonant ring structure with the S‐shaped structure, a single‐sided printed heterogeneous type I LHM is designed; By rotating and combining the designed heterogeneous type I LHM, the heterogeneous type II LHM are formed. After electromagnetic simulation and S‐parameter extraction, it is confirmed that the heterogeneous type I LHM and the heterogeneous type II LHM have negative refraction characteristics at 1.8–2.3 and 2.5–3.2 GHz, respectively. After loading on the dipole antenna, the resonant frequency of the dipole antenna is reduced from 2.45 to 1.68 GHz, that is, loading heterogeneous type I and heterogeneous type II LHM can realize the miniaturization of the dipole antenna, which is 29.7% smaller than the previous design in terms of size reduction. [ABSTRACT FROM AUTHOR]

By incorporating higher order formulation and one‐step leapfrog alternating direction implicit (ADI) procedure, unconditionally stable perfectly matched layer implementation is proposed for terminating frequency‐dependent left‐handed material in finite‐difference time‐domain lattice. To be more specific, frequency‐dependent left‐handed material can be calculated by the piecewise linear recursive convolution method. The proposed scheme shows advantages of higher order formulation and one‐step leapfrog ADI procedure in terms of enhancing absorbing performance, improving computational efficiency and simulating open region problems. The effectiveness is demonstrated through the computational domain with dipole antenna model above the left‐handed material slab. From results, it can be concluded that the proposed formulation can obtain considerable absorption, outstanding efficiency, and improved entire performance. Meanwhile, the proposed scheme also keeps its stability when time step far exceeds the Courant‐Friedrich‐Levy condition. [ABSTRACT FROM AUTHOR]

The purpose of this work is to investigate theoretically the characteristics of confined electromagnetic modes propagating along the interfaces of a multilayer device. This one dimensional (ID) sensor is formed by stacking a left-handed material (LHM) layer between a SiCt2-glass prism and a dielectric gap layer in contact with gold (Au). The results indicate that the total thickness of the LHM layer and dielectric gap, in optimum conditions, give the ability of tuning significantly the characteristics of the resonant modes correlated to surface plasmons (SPs) propagation along the interfaces of the designed device. By considering two arrangements between LHM and Au, two opposite resonant behaviors observed in p-reflectance spectra are analyzed in the angular interrogation mode and discussed thoroughly. [ABSTRACT FROM AUTHOR]

This article designs a hexagonal left‐handed material (LHM) and proposes a microstrip antenna with low radar cross‐section (RCS) based on this new LHM. The modified antenna RCS is significantly reduced without reducing radiation performance compared with two reference antennas. The scattering distribution shows the RCS reduction is attributable to the LHM. Antenna prototypes are fabricated and measured to verify the simulation. As a result, the modified antenna realized RCS reduction while maintaining radiation performance, with 19.5 dB maximum RCS reduction at 1.16 GHz, and the out‐of‐band RCS reduced due to the converged electromagnetic wave caused by the LHM. [ABSTRACT FROM AUTHOR]

This paper introduces a 3-D spherical spiral expansion of the split ring resonator (SRR) commonly used to achieve negative permeability. The spherical spiral unit cell is shown to produce negative permeability over a much wider bandwidth than the traditional SRRs, and also to be capable of producing wideband negative permittivity or a double-negative response, depending on the orientation of the unit cell with respect to the incident electric field. The current structures leading to this phenomenon are discussed. Simulated and measured results are presented. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ternary photonic crystal layer is examined for refractometric applications. • One of the layers is assumed to left-handed material (LHM). • The transmission spectrum is studied and found to exhibit a transmission peak. • The peak shift due to any change in the index of the analyte is investigated. • The peak shift can be enhanced with the change of the LHM parameters. Abstract A ternary photonic crystal with left-handed material (LHM) layer is examined for refractometric applications. One of the layers is assumed to be air and treated as an analyte. The transmittance from the ternary photonic crystal is studied in details and the wavelength shift due to the change in the refractive index of the analyte is investigated. The transmittance is investigated with the parameters of the LHM. It is found that the wavelength shift can be significantly enhanced with the decrease of both real part of the LHM permittivity and thickness. [ABSTRACT FROM AUTHOR]

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This paper aims to establish a design tool to design the metamaterial microstructures with specific electromagnetic properties easily and conveniently, including the design methods of metamaterial microstructures and the corresponding program codes. For the patch type microstructure and several typical metamaterials (such as the single-negative metamaterials with specific negative permeability, left-handed metamaterials with specific material constants at the prescribed frequency; single negative metamaterials and left-handed metamaterials in prescribed frequency bands), the topology optimization models, solving schedules and corresponding implementation program codes for microstructure design are presented in detail. Several typical metamaterial microstructures with different design requirements are designed concretely. The results illustrated the correctness and validity of the design methods and the corresponding program codes. The designing method proposed and the program codes developed in this paper provide an effective tool for the design of metamaterial microstructure with specific function for the designers. [ABSTRACT FROM AUTHOR]

We investigate the electromagnetic wave behavior and its characterization using collective variables technique. Second-order dispersion, first- and second-order nonlinearities, which strongly act in a left-handed nonlinear transmission line with series varactor diodes, are taken into account. Four frequency ranges have been found. The first one gives the so-called energetic soliton due to a perfect combination of second-order dispersion and first-order nonlinearity. The second frequency range presents a dispersive soliton leading to the collapse of the electromagnetic wave at the third frequency range. But the fourth one shows physical conditions which are able to provoke the appearance of wave trains generation with some particular waves, the rogue waves. Moreover, we demonstrate that the number of rogue waves increases with frequency. The soliton, thereafter, gains a relative stability when second-order nonlinearity comes into play with some specific values in the fourth frequency range. Furthermore, the stability conditions of the electromagnetic wave at high frequencies have been also discussed. [ABSTRACT FROM AUTHOR]

Composite right/left-handed (CRLH) metamaterial unit cell whose ground-plane is defected with a rectangular dielectric slot is used to develop a single and multi-pole pole bandpass filter. The unit cell comprises of serially connected interdigital capacitors whose junction is connected to a short-circuited inductive stub. By defecting the ground-plane of the unit cell's structure with a dielectric slot, which is located immediately below the unit cell, enables substantial tuning of the filter's center frequency in the order of 26.5%. This is achieved with minimal effect on the unit cell's insertion and return-loss performance including its selectivity. The filters were fabricated on conventional dielectric substrate and their performance measured to verify the design methodology. The proposed technique eases the trade-off constraints and makes possible the realization of challenging filter specifications constituted from CRLH unit cells using distributed transmission-lines. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:39-45, 2014. [ABSTRACT FROM AUTHOR]

In this paper two novel left-handed composite metamaterials consisting of SRRs, wire and single sided S-shaped resonators are proposed. One of them is a reduced-size resonator which uses superposition hypothesis to achieve adjacent resonances for a much broader negative refraction passband. The other is a modified planar structure with improved electromagnetic coupling and reduced electrical size. Both structures are truly matched to free space in almost whole left-handed frequency band. It will be shown that these metamaterials are robust to the fabrication errors of misalignment printing on both sides of the substrate. The superior performance of these structures are investigated numerically and experimentally and compared with the other split ring resonators. Wedge shape simulation and experimental results confirm the left-handed passband. [ABSTRACT FROM AUTHOR]

A symmetric 3-layer slab waveguide with a left-handed material as a guiding layer is examined analytically for cover refractive index detection. The TM mode dispersion relation of the proposed waveguide is investigated. The sensitivity of the proposed sensor to changes in the cover refractive index and the power flowing within each layer are presented. Some unusual features are found; for example, the sensitivity of the proposed sensor is negative. Moreover, the sensitivity improvement compared with the conventional 3-layer waveguide sensor is approximately a factor of 6. [ABSTRACT FROM AUTHOR]

We report on a new kind of planar left-handed metamaterial with both simulations and experiments in this article. Dual electric and magnetic resonance frequency bands are experimentally realized by introducing two different metallic elements in one unit cell, which offers a convenient approach in building dual-band or multiband negative-index metamaterials. The effective electromagnetic parameters obtained from the measured S-parameters indicate that negative refractive indexes are verified near 8.5 and 12 GHz with both negative permittivity and negative permeability. Field and current distribution at the dual resonances are also examined. At last, we calculated the radiated power of the magnetic dipole moments along y-axis. The idea can help us to fabricate dual-band or multiband metamaterial absorbers, filters, and antennas. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:493-497, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27399 [ABSTRACT FROM AUTHOR]

The optical transmission properties of a structure consisting of N identical pairs of left- and right-materials are investigated theoretically and numerically. Maxwell's equations are used to determine the electric and magnetic fields of the incident waves at each layer. Snell's law is applied and the boundary conditions are imposed at each layer interface to calculate Fresnel coefficients. Expressions for reflectance and transmittance of the structure are given in terms of these coefficients. In the numerical results the transmittance of the structure is computed and illustrated as a function of frequency under different values of N. Minimum transmittance is achieved by using high and low opposite refractive indices of left and right materials of each pair of the structure. The frequency band of this transmittance is reduced by decreasing N. Maximum transmittance is demonstrated by using two slabs of the same width and opposite refractive indices placed between two dielectric media of the same kind. The effect of frequency and angle of incidence is very weak in these structures as compared to their all-dielectric counterparts. Moreover the obtained results are in agreement with the law of conservation of energy. [ABSTRACT FROM AUTHOR]

Based on the ABCD matrix formalism, the propagation property of an Airy beam from right-handed material (RHM) to left-handed material (LHM) is investigated. The result shows that when the Airy beam propagates in the LHM, the intensity self-bending due to its propagation in the RHM can be compensated. In particular, if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is nL = -1, the transverse intensity distribution of the Airy beam can return to its original state. [ABSTRACT FROM AUTHOR]

A three-layer planar waveguide sensor consisting of thin left-handed material core layer is investigated for sensing applications. The sensitivity of the proposed sensor to the changes in the refractive index of the cladding is presented and studied for TE-polarized light. It is observed that the sensitivity of the proposed sensor is improved compared to that of the conventional three-layer slab waveguide sensor. It is also found that the sensitivity of the structure proposed is negative and critically dependent on the dispersive permittivity and permeability of the core layer. [ABSTRACT FROM AUTHOR]

In this paper a waveguide structure consisting of a pair of left-handed material (LHM) and dielectric slabs inserted in vacuum is investigated theoretically. Maxwell's equations are used to determine the electric and magnetic fields of the incident waves at each layer. Snell's law is applied and the boundary conditions are imposed at each layer interface to calculate the reflected and transmitted powers of the structure. Numerical results are illustrated to show the effects of frequency, angle of incidence and LHM thickness on the transmitted power when the refractive index of the dielectric layer changes. The same procedure is repeated to show the variation of the transmitted power with the change in the mentioned parameters under different values of dissipation factor of the lossy LHM. Consequently, two cases of the LHM are considered, loss-less case and loss case. The results obtained, are in agreement with the law of conservation of energy. [ABSTRACT FROM AUTHOR]

A novel frequency-sensitive switching control effect induced by two-photon resonance for TM wave in a periodic layered medium containing left-handed material (LHM) and electromagnetically induced transparency (EIT) medium is suggested. Since the optical response of an atomic medium can be controlled via tunable quantum interference between multilevel transition pathways driven by an external control field, a periodic layered medium whose unit cells consist of left-handed medium and EIT atomic vapor can exhibit some intriguing properties: I) the band structure (and hence the reflection and transmission of light) will show flexible optical response sensitive to frequency, ii) an unusual Klein tunneling effect of light occurs in the present LHM-EIT-based medium, and iii) the controllable band structure depending on the external control field would have potential applications in designing new devices such as photonic switches, photonic logic gates and photonic transistors [ABSTRACT FROM AUTHOR]

Based on ceramics S-shaped left-handed materials with magnetic resonance and electric anti-resonance were prepared by screen printing. The microwave transmittance properties of these samples in a rectangular waveguide were experimentally investigated. It is found that the two frequency bands of negative effective permittivity and negative effective permeability overlap from 8.5 to 9.46 GHz, which is left-handed materials pass-band and the bandwidth is about 1 GHz. Magnetic resonance is due to magnetic coupling between magnetic field component of external fields and the samples, in which the effective permeability could be negative. And electrical anti-resonance originated from electric coupling may contribute to negative effective permittivity. This based on ceramics substrate S-shaped construct possess both remarkable electric and magnetic resonances, which provides a flexible element for constructing planar left-handed materials. [ABSTRACT FROM AUTHOR]

This article presents modeling and analysis techniques for and reveals the actual working mechanism of longitudinal metamaterial bars as elastic wave absorbers. A metamaterial-based elastic wave absorber can be a uniform isotropic bar with many tiny spring-mass subsystems attached at separated longitudinal locations. In the literature, each cell that consists of a bar segment and an attached spring-mass subsystem is modeled as a discrete system of two degrees of freedom by integration and/or finite difference, and the idealized model becomes a dispersive medium for elastic waves and has a stop band that allows no waves to propagate forward. This work shows that these idealized models can be used only for elastic waves having wavelengths much longer than the unit cell's length. Moreover, it is revealed that a metamaterial-based elastic wave absorber is actually based on the concept of conventional mechanical vibration absorbers, which uses the local resonance of subsystems to generate inertia forces to work against the external load and prevent elastic waves from propagating forward. This concept is extended to design a broadband absorber that works for elastic waves of any wavelengths, including waves having wavelengths shorter than the unit cell's length. Numerical examples validate the design and reveal the cause of stop band. Moreover, the effect of negative effective mass and acoustic and optical modes are explained. [ABSTRACT FROM AUTHOR]

Free-space microwave measurements are applied on composite metamaterials (CMMs) consisting of split ring resonators (SRRs) and wires, also known as left-handed material. Our experiments are based on a type of CMMs with unique configurations and the transmission and reflection measurements performed in free space exhibit a pass band at about 9 GHz. Simulation results are also given, which are in good agreements with experiments. The widely belief of the pass band is that the stop bands of the SRRs alone and the wires alone constitute a clear demonstration of left-handed (LH) behavior. The LH behavior only take place in the medium with simultaneously negative permittivity ℇ, and permeability μ, also called double negative materials. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1865–1868, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24465 [ABSTRACT FROM AUTHOR]

A three-dimensional lens with magnetic field control of the index of refraction and focal length has been designed and characterized over 2-18 GHz. The lens is made of a lattice of cross-wire resonators and ferrite cubes. For the lattice without the ferrite cubes, a refractive index n ≈ -1 is measured at 11.25 GHz. With the introduction of ferrite cubes in the lattice, n could be tuned over the range -1.2 to +1.8 for nominal bias magnetic fields H. The focal point for the lens with n ≈ -1, for example, could be displaced by 2 cm by tuning H from 4100 to 4125 Oe. Theoretical estimates of the lens characteristics are in agreement with the data. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2804–2807, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23847 [ABSTRACT FROM AUTHOR]

We have proposed and theoretically investigated a left-handed material (LHM) slab composed of porous-nanostructed metal-dielectric-metal (MDM) networks for realizing negative refraction index at optical frequencies. In our design, whatever the polarization direction, provided that the electric field vector of incident EM wave is parallel to the metallic network, can “see” an equivalent LHM slab due to the symmetry and periodicity of the porous arrays. Another point needed to be highlighted is that by adjusting the periodicity of the porous arrays, a broad band of negative refraction index can be obtained. This shed the bright light on realizing negative refraction index for nanooptics and imaging applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 216–220, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23022 [ABSTRACT FROM AUTHOR]

The four-wave mixing (FWM) effect in a so-called left-handed material (LHM) with a third-order nonlinear response is studied. The theoretical models for the wavelength conversion (WC) and parametric amplification (PA) based on the FWM in the LHM are established when the signal falls in the frequency range of backward or forward wave. Analytical formulas for the WC efficiency and PA gain are derived. The influences of the pump powers, the phase mismatch, and the interaction length on the performances of the WC and PA are analyzed. The phase-match dependence of the performance is reduced by carefully controlling the pump powers. [ABSTRACT FROM AUTHOR]

The paper is concerned with the propagation characteristics of TE surface waves in a planar wave-guide structure of a lateral antiferromagnetic-non magnetic super lattices (LANS) film bounded by a nonlinear dielectric cover and a left-handed substrate (LHM). In LHM substrate both permittivity and magnetic permeability are negative in definite frequency range. We study nonlinear dispersion properties of the TE surface waves and illustrate the power flow variation with the wave index in three different cases, i.e., when both permittivity and magnetic permeability are negative, when permittivity is negative and permeability is positive, and when both permittivity and magnetic permeability are positive. In the first case, we found that surface waves are backward traveling and the wave power variation with the wave index shows bistability behavior. We also found that by increasing the film thickness the waves turn from forward to backward traveling in the second case. In the third case, surface waves are always forward traveling. [ABSTRACT FROM AUTHOR]

A new leaky wave antenna based on channel guide filled with left-handed material (LHM), operating in evanescent surface mode of TM polarization, is presented for millimeter wave applications. A transverse equivalent network that yields a dispersion relation in closed form is employed to analyze the leakage characteristics of the antenna. Numerical results are presented for the phase and leakage constants of the antenna in terms of different geometric parameters and dielectric distributions. Besides, the frequency dependences of the leaky characteristics for the present antenna are given, from which the backward radiation is clearly demonstrated. [ABSTRACT FROM AUTHOR]

We will investigate the surface plasmon (SP) resonances of a dielectric-sandwiched metamaterial thin film. The parameters of the metamaterial are chose so that it has both negative $$\epsilon$$ and μ in visible frequency range. We use transfer matrix method to calculate the attenuated total reflection (ATR) spectra of the layered system to investigate the variation of SP resonances and the associated resonance strength. The results show that, for both p- and s-polarized incident lights, the plasmonic resonances can be manipulated by changing the thickness of the metamaterial. Otherwise, the plasmonic resonance strength for each SP mode can be tuned to become a maximum with proper slab thickness and light frequency for both polarized lights. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel method to calculate the effective negative refractive index of a left-handed material (LHM)—a composite of split-ring resonators (SRRs) and thin wire structures. A LHM slab was first fabricated and then the measured transmission and reflection results were used to determine the LHM passband. To obtain the effective negative-refractive index, a microwave beam was obliquely launched to illuminate the slab for which a 2D spatial-field profile of the refracted beam outside the slab was obtained by scanning the lateral shifting of the field with respect to normal for a band of frequencies. A lateral shift of the refracted beam towards the same side of the incident beam for the LHM passband confirmed negative refraction in the LHM slab and the refractive index calculated for that frequency region was conclusively negative according to Snell's law. The presented method provides an alternate and efficient way to measure the effective refractive index of a LHM. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 593–596, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21417 [ABSTRACT FROM AUTHOR]

The Doppler effects for the reflected wave from moving media are systemically analyzed in this paper. The theoretical formula for the Doppler shift in left-handed material, which is described by Drude's dispersion model, is presented. This formula is examined by first-principles numerical experiments, which are in agreement with the theoretical results. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 76–79, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21086 [ABSTRACT FROM AUTHOR]

Using the equifrequency surfaces (EFS) to describe negative refractions in left-handed materials (LHMs) and photonic crystals (PCs), negative phase and negative group refractive indexes in LHMs were compared with positive phase and negative group refractive indexes in PCs. The refractive indexes in PCs were dependent on frequencies and incident angles of electromagnetic wave, while indexes in LHMs were constant in the left-handed region. Furthermore, the phase compensating effect resulting from the negative phase refractive index was addressed to distinguish the perfect lens made of LHMs from the superlens realized in the all angle negative refraction (AANR) region of PCs. [ABSTRACT FROM AUTHOR]

In this paper, we present an analysis of the dispersion properties for a left-handed material (LHM) using the 3D finite-difference time-domain (FDTD) method. We study the classic LHM structure composed of wire and split-ring resonators in a unit cell and calculate the resonant frequencies in order to produce the corresponding dispersion curve. The comparisons made between our numerical results and those previously published are in good agreement. In addition, through the incorporation of the Padé approximation with our FFT results, we reduce the computational time and enhance the results obtained. We anticipate that the development of such analysis tools for dispersion analysis will lead to an efficient way of characterizing LHMs and will facilitate the study of such metamaterial composites. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 394–397, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20833 [ABSTRACT FROM AUTHOR]

Backward-wave (BW) materials that have simultaneously negative real parts of their electric permittivity and magnetic permeability can support waves where phase and power propagation occur in opposite directions. These materials were predicted to have many unusual electromagnetic properties, among them amplification of the near-field of a point source, which could lead to the perfect reconstruction of the source field in an image [J. Pendry, Phys. Rev. Left. vol. 85, pg. 3966, 2000]. Often systems containing BW materials are simulated using the finite-difference time-domain technique. We show that this technique suffers from a numerical artifact due to its staggered grid that makes its use in simulations involving BW materials problematic. The pseudospectral time-domain technique, on the other hand, uses a collocated grid and is free of this artifact It is also shown that when modeling the dispersive BW material, the linear frequency approximation method introduces error that affects the frequency of vanishing reflection, while the auxiliary differential equation, the Z-transform, and the bilinear frequency approximation method produce vanishing reflection at the correct frequency. The case of vanishing reflection is of particular interest for field reconstruction in imaging applications. [ABSTRACT FROM AUTHOR]

In this article, we present an experimental and numerical study of novel optical properties of two-dimensional dielectric photonic crystals (PCs) which exhibit negative refraction. We investigate two mechanisms which utilize the band structure of the PC to generate a negative effective index of refraction (neff<0) and demonstrate the negative refraction experimentally. To the isotropic extend of neff, different PC slab structures are employed to focus the radiation of a point source. It is shown experimentally that the PC can generate an image of the source with subwavelength resolution in the vicinity of the PC interface. Using a different PC, one can also obtain a far field focusing. In the latter case, we explicitly show the flat lens behavior of the structure. These examples indicate that PC-based lenses can surpass limitations of conventional lenses and lead to novel optics applications. [ABSTRACT FROM AUTHOR]

We study the properties of left-handed materials (LHMs) with the precise help of Sommerfeld integrals. First we argue by energy conservation principles that LHM has to be a backward-wave material (BWM). Then we derive the equivalence of the loss and the Sommerfeld far-field radiation conditions for a BWM. Next, we solve the realistic Sommerfeld problem of a point source over an LHM half-space and an LHM slab. This analysis lends physical insight into the interaction of a point source field with an LHM, showing that super-resolution is possible with an LHM slab. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 369–373, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20307 [ABSTRACT FROM AUTHOR]

Here, we analyze the transverse-magnetic (TM) wave interaction with a pair of slabs, one being an epsilon-negative (ENG) layer in which the real part of permittivity is assumed to be negative while its permeability has positive real part, and the other being a mu-negative (MNG) layer that has the real part of its permeability negative but its permittivity has positive real part. Although wave interaction with each slab by itself has predictable features, we show that the juxtaposition and pairing of such ENG and MNG slabs may, under certain conditions, lead to some unusual features, such as resonance, complete tunneling, zero reflection and transparency. The field distributions inside and outside such paired slabs are analyzed, and the Poynting vector distributions in such structures are studied. Using equivalent transmission-line models, we obtain the conditions for the resonance, complete tunneling and transparency, and we justify and explain the field behavior in these resonant paired structures. Salient features of the tunneling conditions, such as the roles of material parameters, slab thicknesses, dissipation, and angle of incidence are discussed. The analogy and correspondence between the ENG-MNG pair and the pair of a slab of conventional material juxtaposed with a "double-negative" medium is also discussed. Finally, a conceptual idea for a potential application of such a "matched" lossless ENG-MNG pair in "ideal" image displacement and image reconstruction is proposed. [ABSTRACT FROM AUTHOR]

Gaussian beam propagation in structures containing meta-materials with negative permittivity and negative permeability is numerically studied by using a bidirectional wide-angle finite-difference beam propagation method. Illustrative and quantitative views are given for various anomalous behaviors, such as the negative angle of refraction, beam refocusing, arbitrarily thin distributed Bragg reflector, and negative lateral shift of the reflected beam from a grounded slab, by a Gaussian beam propagating in some meta-material structures. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 292–296, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10898 [ABSTRACT FROM AUTHOR]

Resonator modes in two-dimensional laser cavities with curved end mirrors filled with a left-handed material were investigated numerically using the extended Fox-Li mode calculation method. The results reveal that the phase profile on the curved end mirrors of a left-handed cavity is inverted relative to that of a cavity filled with a right-handed material. Furthermore, we show that the phase on the end mirrors takes discrete values of zero and ± π under stable resonator conditions, while it varies continuously under unstable resonator conditions. The differences between stable and unstable resonators significantly alter the far-field patterns of the lowest-loss modes. [ABSTRACT FROM AUTHOR]

A fiber with left-handed material as the core, and right-handed material as the cladding has been analyzed by using Maxwell's equations. A Helmholtz equation is obtained and solved. Thus, some characteristic equations are obtained and studied further. Some novel propagation characteristics in LHM fiber are obtained. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1039–1041, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22335 [ABSTRACT FROM AUTHOR]

We report the effective complex permittivity and permeability of 1D planar left-handed transmission-line metamaterials. These metamaterials are formed on coplanar waveguide (CPW) with simultaneous load of series-capacitive and shunt-inductive elements in periodic intervals. By employing our self-calibrated method of moments (MoM), the effective permittivity and permeability of these 1D metamaterials are numerically derived to illustrate the propagating and evanescent guided-wave behaviors over a microwave frequency range. We demonstrate that, in a certain frequency band, the permittivity and permeability simultaneously become negative with zero imaginary parts, and the transmission phase of a finite-extent CPW metamaterial becomes negative, as exhibited by both simulation and measurement. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1050–1052, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21597 [ABSTRACT FROM AUTHOR]

We report free space, microwave measurements with varying incidence angle on a material that exhibits a negative index of refraction. The experiments measure the index of refraction directly, for normal incidence, on prisms with three different apex angles. Snell's Law and the measured index are then used to verify refraction for off-normal incidence. The metamaterials used to construct the prisms are comprised of parallel metallic layers of posts and either "Greek key" spiral or split ring resonators. Despite this highly anisotropic composition, the measured refractive index was found to be nearly constant for exit angles up to 52° off the normal to the prism hypotenuse. In addition to being the first free space experimental verification of Snell's Law off the optical axis for this type of metamaterial, the measurements prove that the common parallel plate structures of negative index metamaterials are not acting as guided wave media. [ABSTRACT FROM PUBLISHER]

The perfectly matched layer (PML) absorbing boundary condition (ABC) is extended to truncate the boundary of left-handed materials in the Finite-Difference Time-Domain (FDTD) simulation. The uniaxial material parameters are given in the frequency domain, and discretized in the FDTD update procedure by means of the Z-Transform technique. The effectiveness of the PML is demonstrated by numerical results. [ABSTRACT FROM PUBLISHER]

This paper investigates the cutoff wavenumbers and their geometric and dielectric dependence in rectangular waveguides filled with left‐handed material (LHM) and/or right‐handed material (RHM). A rigorous hybrid mode analysis of these structures produces the dispersion equations and the formulations of cutoff wavenumbers for the first three modes. It is shown how the geometric and dielectric parameters may influence the cutoff wavenumbers of the waveguides filled with LHM and/or RHM. The graphs of cutoff wavenumbers over a range of geometric and dielectric parameters sufficiently wide to cover most requirements of design and application have been plotted. The cutoff wavenumbers of waveguides with LHM increase as the thicknesses or the absolute values of permittivity of LHM increase. It is noted that the variation rules of cutoff wavenumbers in waveguides with LHM show different changing tendencies compared with the waveguides with RHM. [ABSTRACT FROM AUTHOR]

By using the method of Finite Difference Time Domain (FDTD) and the technology of Compute Unified Device Architecture (CUDA), the propagation characteristics of electromagnetic waves in Left‐Handed Materials (LHM) have been studied in this paper. The LHM slab was matched with the free space and the secondary focusing phenomenon of LHM was simulated. Compared with the serial FDTD program, our work showed that this method had a high accuracy. The phase compensation effect and the inverse Snell effect of LHM were also discussed by using the parallel FDTD method based on CUDA, which further proved that our results were consistent with the theoretical study. By comparing the calculation time of traditional FDTD program with that of the CUDA based parallel FDTD program, we conclude that the latter is more efficient than the former. This parallel method can be used as a more efficient way to study LHM. [ABSTRACT FROM AUTHOR]

A compact ring resonator using a negative-refractive-index microstrip line is presented. It is demonstrated that the ring structure resonates even with an inner diameter of zero. The total circumference of the proposed resonator is reduced by 84%, as compared to a conventional ring resonator at 1.2 GHz. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 294–295, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20799 [ABSTRACT FROM AUTHOR]