Radiation from surface with periodic boundary of metamaterials excited by a current
TL;DR: In this paper, a rigorous modeling and analysis of electromagnetic wave transformation and radiation from the periodic boundary of metamaterials is presented, where the nature of the phenomenon of resonant radiation and the influence of various parameters on it are investigated.
Abstract: The rigorous modeling and analysis of electromagnetic wave transformation and radiation from the periodic boundary of metamaterial are presented. The nature of the phenomenon of resonant radiation and the influence of various parameters on it are investigated. The study is carried out with the objective of potential applications to antenna design. Simulated results show that very high directivity can be obtained and that beam steering can be achieved by adjusting proper parameters.
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TL;DR: Duan et al. as mentioned in this paper reviewed the research progress in reversed Cherenkov radiation in double-negative metamaterials starting from the first experimental verification of the DNMs reported in 2001, including theories, numerical computation and simulation and experiments.
Abstract: We review the research progress in reversed Cherenkov radiation in double-negative metamaterials (DNMs) starting from the first experimental verification of the DNMs reported in 2001, including theories, numerical computation and simulation and experiments. We also discuss the potential applications to particle detectors and highpower microwave or millimeter-wave devices, including the oscillators and amplifiers, and the formidable challenges needed to be resolved before the benefits of using such artificial materials can be harvested. Corresponding author: Z. Y. Duan (zhyduan@uestc.edu.cn).
115 citations
TL;DR: In this paper, the eigen surface waves of the periodic interfaces of metamaterials are studied and the results obtained in the study help in the understanding of the nature of the diverse types of electromagnetic wave resonant transformation by the periodic surfaces.
Abstract: The paper is focused on the study of eigen surface waves of the periodic interfaces of metamaterials. A wide range of numerical experiments is performed on the basis of an accurate solution to the eigen boundary value problem. The peculiarities of eigen waves in dispersive media are revealed. The results obtained in the study help in the understanding of the nature of the diverse types of electromagnetic wave resonant transformation by the periodic surfaces of metamaterials.
10 citations
TL;DR: In this paper, a general formulation of Dyadic Green's function for a point source above a two-dimensional periodic boundary is presented in spectral form by considering only the zero term of the infinite Floquet modes.
Abstract: A general formulation of Dyadic Green’s function for a point source above a two-dimensional periodic boundary is presented in spectral form. This formulation is simplified by considering only the zero term of the infinite Floquet modes. Then it is applied to obtain the Dyadic Green’s function of a printed source above a dielectric slab with periodically defected ground plane by using a generalized equivalent network of this defected ground plane. This equivalent network is obtained from the reflection coefficients of the defectedgrounded slab for different angles of incidence. This network includes equivalent impedances of the periodic surface for both TE and TM incident waves. In addition, it includes coupling impedance between the equivalent TE and TM networks. By determining the generalized equivalent network of the ground plane, the problem of the Green’s function can be formulated by coupled TE and TM transmission line networks.
9 citations
TL;DR: In this paper, the effects associated with the resonant transformation of a plane, density modulated electron beam, flying over the periodically uneven boundary of a natural or artificial medium, in the field of volume outgoing waves are modeled.
Abstract: The paper is focused on reliable modeling of the effects associated with the resonant transformation of the field of a plane, density modulated electron beam, flying over the periodically uneven boundary of a natural or artificial medium, in the field of volume outgoing waves. Here, the general information (analytical basis) is presented on the peculiarities and principal characteristics of electromagnetic fields arising in the situations under consideration, on the procedures for regularization of model boundary value problems describing these situations, and on possible eigen modes of periodic structures. Without relying on this information, it is impossible to advance considerably effectively in solving numerous urgent physical problems (establishing the conditions providing anomalously high levels of Vavilov-Cherenkov and/or Smith-Purcell radiation; diagnostics of beams of charged particles, artificial materials and media) and in practical implementation of new knowledge about the effects of diffraction radiation and their wave analogues in new devices and instruments of optoelectronics, high-power electronics, antenna, and accelerator technology.
7 citations
Cites methods from "Radiation from surface with periodi..."
...To solve the problem (1) numerically, we use the approach from [18, 23, 24], and it is a version of the analytical regularization method [19, 21, 25], which can be described briefly as follows....
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TL;DR: In this paper, the dispersion effect through the Drude and Lorentz model is studied on achieving transparency and reduction of the total scattering cross section of a spherical scatterer.
Abstract: Dispersive effect through the Drude and Lorentz model is studied on achieving transparency and reduction of the total scattering cross section of a spherical scatterer. Some full wave numerical results in frequency domain are presented and illustrated that dispersion as a constraint, limiting the bandwidth of transparency phenomenon. The losses are also included and shown that for low losses there is not much difference in comparison with the lossless cases.
7 citations
References
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TL;DR: The introduction of a single chiral resonance leads to negative refraction of one polarization, resulting in improved and simplified designs of negatively refracting materials and opening previously unknown avenues of investigation in this fast-growing subject.
Abstract: Negative refraction is currently achieved by driving the magnetic permeability and electrical permittivity simultaneously negative, thus requiring two separate resonances in the refracting material. The introduction of a single chiral resonance leads to negative refraction of one polarization, resulting in improved and simplified designs of negatively refracting materials and opening previously unknown avenues of investigation in this fast-growing subject.
1,522 citations
TL;DR: In this paper, the fundamental electromagnetic properties of left-handed metamaterials and the physical realization of these materials are reviewed based on a general transmission line (TL) approach.
Abstract: Metamaterials are artificial structures that can be designed to exhibit specific electromagnetic properties not commonly found in nature. Recently, metamaterials with simultaneously negative permittivity (/spl epsiv/) and permeability (/spl mu/), more commonly referred to as left-handed (LH) materials, have received substantial attention in the scientific and engineering communities. The unique properties of LHMs have allowed novel applications, concepts, and devices to be developed. In this article, the fundamental electromagnetic properties of LHMs and the physical realization of these materials are reviewed based on a general transmission line (TL) approach. The general TL approach provides insight into the physical phenomena of LHMs and provides an efficient design tool for LH applications. LHMs are considered to be a more general model of composite right/left hand (CRLH) structures, which also include right-handed (RH) effects that occur naturally in practical LHMs. Characterization, design, and implementation of one-dimensional and two-dimensional CRLH TLs are examined. In addition, microwave devices based on CRLH TLs and their applications are presented.
1,285 citations
TL;DR: In this article, it is shown that a slab of metamaterial with negative permittivity and permeability can act as a phase compensator/conjugator and, by combining such a slab with another slab made of a conventional dielectric material, one can, in principle, have a 1D cavity resonator whose dispersion relation may not depend on the sum of thicknesses of the interior materials filling this cavity, but instead it depends on the ratio of these thicknesses.
Abstract: We present and analyze theoretically some ideas for thin one-dimensional (1D) cavity resonators in which a combination of a conventional dielectric material and a metamaterial possessing negative permittivity and permeability has been inserted. It is shown that a slab of metamaterial with negative permittivity and permeability can act as a phase compensator/conjugator and, thus, by combining such a slab with another slab made of a conventional dielectric material, one can, in principle, have a 1D cavity resonator whose dispersion relation may not depend on the sum of thicknesses of the interior materials filling this cavity, but instead it depends on the ratio of these thicknesses. In other words, one can, in principle, conceptualize a 1D cavity resonator with the total thickness far less than the conventional /spl lambda//2. Mathematical steps and physical intuitions relevant to this problem are presented.
600 citations
TL;DR: In this article, a compact one-dimensional phase shifter is proposed using alternating sections of negative refractive index (NRI) metamaterials and printed transmission lines (TL).
Abstract: A compact one-dimensional phase shifter is proposed using alternating sections of negative refractive index (NRI) metamaterials and printed transmission lines (TL). The NRI metamaterial sections consist of lumped element capacitors and inductors, arranged in a dual TL (high-pass) configuration. By adjusting the NRI-medium lumped element values, the phase shift can be tailored to a given specification. Periodic analysis is applied to the structure and design equations are presented for the determination of the lumped element parameters for any arbitrary phase shift. To validate the design, various phase shifters are simulated and tested in coplanar waveguide (CPW) technology. It is demonstrated that small variations in the NRI-medium lumped element values can produce positive, negative or 0/spl deg/ phase shifts while maintaining the same short overall length. Thus, the new phase shifter offers some significant advantages over conventional delay lines: it is more compact in size, it exhibits a linear phase response around the design frequency, it can incur a phase lead or lag which is independent of the length of the structure and it exhibits shorter group delays.
400 citations
TL;DR: The fundamental electromagnetic properties of left-handed materials (LHMs) are reviewed and verified by finite-element method full-wave analysis using rectangular waveguide structures loaded by a LHM and adopting an effective medium approach as discussed by the authors.
Abstract: The fundamental electromagnetic properties of left-handed materials (LHMs) are reviewed and verified by finite-element method full-wave analysis using rectangular waveguide structures loaded by a LHM and adopting an effective medium approach. The negative phase velocity, positive intrinsic impedance, and modified boundary conditions at an interface with a right-handed medium are verified by loading a waveguide section with a LHM that has edges perpendicular to the waveguide axis. In addition, the negative angle of refraction is demonstrated by loading the junction of a T-junction waveguide with a LHM having one edge 45° with respect to the waveguide axis. These properties are shown by the evolution of wave fronts in the LHM and by analysis of the S-parameters of the waveguide structures.
183 citations