Patent•
Variable metamaterial apparatus
16 Feb 2007-
TL;DR: In this paper, the properties of metamaterials are adjustable according to active feedback of interaction with electromagnetic waves, and the properties are adjusted according to an active feedback model of the interaction with the electromagnetic waves.
Abstract: Artificial materials, such as metamaterials, include adjustable properties. In some approaches the properties are adjustable according to active feedback of interaction with electromagnetic waves.
Citations
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Patent•
17 Mar 2008
TL;DR: In this article, the authors present an approach for using composite left and right handed (CRLH) metamaterial (MTM) structure antenna elements and arrays to provide radiation pattern shaping and beam switching.
Abstract: Apparatus, systems and techniques for using composite left and right handed (CRLH) metamaterial (MTM) structure antenna elements and arrays to provide radiation pattern shaping and beam switching.
396 citations
Patent•
AT&T1
TL;DR: In this paper, the authors describe a system that receives, by a feed point of a dielectric antenna, electromagnetic waves from a core coupled to the feed point without an electrical return path, and radiates a wireless signal responsive to the electromagnetic waves being received at the aperture.
Abstract: Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.
330 citations
Patent•
AT&T1
TL;DR: In this paper, a distributed antenna and backhaul system provide network connectivity for a small cell deployment using high-bandwidth, millimeter-wave communications and existing power line infrastructure, rather than building new structures, and installing additional fiber and cable.
Abstract: A distributed antenna and backhaul system provide network connectivity for a small cell deployment. Rather than building new structures, and installing additional fiber and cable, embodiments described herein disclose using high-bandwidth, millimeter-wave communications and existing power line infrastructure. Above ground backhaul connections via power lines and line-of-sight millimeter-wave band signals as well as underground backhaul connections via buried electrical conduits can provide connectivity to the distributed base stations. An overhead millimeter-wave system can also be used to provide backhaul connectivity. Modules can be placed onto existing infrastructure, such as streetlights and utility poles, and the modules can contain base stations and antennas to transmit the millimeter-waves to and from other modules.
298 citations
Patent•
AT&T1
TL;DR: In this article, a distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas.
Abstract: A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.
296 citations
Patent•
AT&T1
TL;DR: In this article, the authors describe a device that facilitates transmitting electromagnetic waves along a surface of a wire that facilitates delivery of electric energy to devices, and sensing a condition that is adverse to the electromagnetic waves propagating along the surface of the wire.
Abstract: Aspects of the subject disclosure may include, for example, a device that facilitates transmitting electromagnetic waves along a surface of a wire that facilitates delivery of electric energy to devices, and sensing a condition that is adverse to the electromagnetic waves propagating along the surface of the wire. Other embodiments are disclosed.
288 citations
References
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TL;DR: The authors' simulations show that a version of the lens operating at the frequency of visible light can be realized in the form of a thin slab of silver, which resolves objects only a few nanometers across.
Abstract: Optical lenses have for centuries been one of scientists’ prime tools. Their operation is well understood on the basis of classical optics: curved surfaces focus light by virtue of the refractive index contrast. Equally their limitations are dictated by wave optics: no lens can focus light onto an area smaller than a square wavelength. What is there new to say other than to polish the lens more perfectly and to invent slightly better dielectrics? In this Letter I want to challenge the traditional limitation on lens performance and propose a class of “superlenses,” and to suggest a practical scheme for implementing such a lens. Let us look more closely at the reasons for limitation in performance. Consider an infinitesimal dipole of frequency v in front of a lens. The electric component of the field will be given by some 2D Fourier expansion,
10,974 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: Recent advances in metamaterials research are described and the potential that these materials may hold for realizing new and seemingly exotic electromagnetic phenomena is discussed.
Abstract: Recently, artificially constructed metamaterials have become of considerable interest, because these materials can exhibit electromagnetic characteristics unlike those of any conventional materials. Artificial magnetism and negative refractive index are two specific types of behavior that have been demonstrated over the past few years, illustrating the new physics and new applications possible when we expand our view as to what constitutes a material. In this review, we describe recent advances in metamaterials research and discuss the potential that these materials may hold for realizing new and seemingly exotic electromagnetic phenomena.
3,893 citations
11 Nov 2005
TL;DR: In this paper, the authors define Metamaterials (MTMs) and Left-Handed (LH) MTMs as a class of two-dimensional MTMs.
Abstract: Preface. Acknowledgments. Acronyms. 1 Introduction. 1.1 Definition of Metamaterials (MTMs) and Left-Handed (LH) MTMs. 1.2 Theoretical Speculation by Viktor Veselago. 1.3 Experimental Demonstration of Left-Handedness. 1.4 Further Numerical and Experimental Confirmations. 1.5 "Conventional" Backward Waves and Novelty of LH MTMs. 1.6 Terminology. 1.7 Transmission Line (TL) Approach. 1.8 Composite Right/Left-Handed (CRLH) MTMs. 1.9 MTMs and Photonic Band-Gap (PBG) Structures. 1.10 Historical "Germs" of MTMs. References. 2 Fundamentals of LH MTMs. 2.1 Left-Handedness from Maxwell's Equations. 2.2 Entropy Conditions in Dispersive Media. 2.3 Boundary Conditions. 2.4 Reversal of Doppler Effect. 2.5 Reversal of Vavilov- Cerenkov Radiation. 2.6 Reversal of Snell's Law: Negative Refraction. 2.7 Focusing by a "Flat LH Lens". 2.8 Fresnel Coefficients. 2.9 Reversal of Goos-H anchen Effect. 2.10 Reversal of Convergence and Divergence in Convex and Concave Lenses. 2.11 Subwavelength Diffraction. References. 3 TLTheoryofMTMs. 3.1 Ideal Homogeneous CRLH TLs. 3.1.1 Fundamental TL Characteristics. 3.1.2 Equivalent MTM Constitutive Parameters. 3.1.3 Balanced and Unbalanced Resonances. 3.1.4 Lossy Case. 3.2 LC Network Implementation. 3.2.1 Principle. 3.2.2 Difference with Conventional Filters. 3.2.3 Transmission Matrix Analysis. 3.2.4 Input Impedance. 3.2.5 Cutoff Frequencies. 3.2.6 Analytical Dispersion Relation. 3.2.7 Bloch Impedance. 3.2.8 Effect of Finite Size in the Presence of Imperfect Matching. 3.3 Real Distributed 1D CRLH Structures. 3.3.1 General Design Guidelines. 3.3.2 Microstrip Implementation. 3.3.3 Parameters Extraction. 3.4 Experimental Transmission Characteristics. 3.5 Conversion from Transmission Line to Constitutive Parameters. References. 4 Two-Dimensional MTMs. 4.1 Eigenvalue Problem. 4.1.1 General Matrix System. 4.1.2 CRLH Particularization. 4.1.3 Lattice Choice, Symmetry Points, Brillouin Zone, and 2D Dispersion Representations. 4.2 Driven Problem by the Transmission Matrix Method (TMM). 4.2.1 Principle of the TMM. 4.2.2 Scattering Parameters. 4.2.3 Voltage and Current Distributions. 4.2.4 Interest and Limitations of the TMM. 4.3 Transmission Line Matrix (TLM) Modeling Method. 4.3.1 TLM Modeling of the Unloaded TL Host Network. 4.3.2 TLM Modeling of the Loaded TL Host Network (CRLH). 4.3.3 Relationship between Material Properties and the TLM Model Parameters. 4.3.4 Suitability of the TLM Approach for MTMs. 4.4 Negative Refractive Index (NRI) Effects. 4.4.1 Negative Phase Velocity. 4.4.2 Negative Refraction. 4.4.3 Negative Focusing. 4.4.4 RH-LH Interface Surface Plasmons. 4.4.5 Reflectors with Unusual Properties. 4.5 Distributed 2D Structures. 4.5.1 Description of Possible Structures. 4.5.2 Dispersion and Propagation Characteristics. 4.5.3 Parameter Extraction. 4.5.4 Distributed Implementation of the NRI Slab. References. 5 Guided-Wave Applications. 5.1 Dual-Band Components. 5.1.1 Dual-Band Property of CRLH TLs. 5.1.2 Quarter-Wavelength TL and Stubs. 5.1.3 Passive Component Examples: Quadrature Hybrid and Wilkinson Power Divider. 5.1.3.1 Quadrature Hybrid. 5.1.3.2 Wilkinson Power Divider. 5.1.4 Nonlinear Component Example: Quadrature Subharmonically Pumped Mixer. 5.2 Enhanced-Bandwidth Components. 5.2.1 Principle of Bandwidth Enhancement. 5.2.2 Rat-Race Coupler Example. 5.3 Super-compact Multilayer "Vertical" TL. 5.3.1 "Vertical" TL Architecture. 5.3.2 TL Performances. 5.3.3 Diplexer Example. 5.4 Tight Edge-Coupled Coupled-Line Couplers (CLCs). 5.4.1 Generalities on Coupled-Line Couplers. 5.4.1.1 TEM and Quasi-TEM Symmetric Coupled-Line Structures with Small Interspacing: Impedance Coupling (IC). 5.4.1.2 Non-TEM Symmetric Coupled-Line Structures with Relatively Large Spacing: Phase Coupling (PC). 5.4.1.3 Summary on Symmetric Coupled-Line Structures. 5.4.1.4 Asymmetric Coupled-Line Structures. 5.4.1.5 Advantages of MTM Couplers. 5.4.2 Symmetric Impedance Coupler. 5.4.3 Asymmetric Phase Coupler. 5.5 Negative and Zeroth-Order Resonator. 5.5.1 Principle. 5.5.2 LC Network Implementation. 5.5.3 Zeroth-Order Resonator Characteristics. 5.5.4 Circuit Theory Verification. 5.5.5 Microstrip Realization. References. 6 Radiated-Wave Applications. 6.1 Fundamental Aspects of Leaky-Wave Structures. 6.1.1 Principle of Leakage Radiation. 6.1.2 Uniform and Periodic Leaky-Wave Structures. 6.1.2.1 Uniform LW Structures. 6.1.2.2 Periodic LW Structures. 6.1.3 Metamaterial Leaky-Wave Structures. 6.2 Backfire-to-Endfire (BE) Leaky-Wave (LW) Antenna. 6.3 Electronically Scanned BE LW Antenna. 6.3.1 Electronic Scanning Principle. 6.3.2 Electronic Beamwidth Control Principle. 6.3.3 Analysis of the Structure and Results. 6.4 Reflecto-Directive Systems. 6.4.1 Passive Retro-Directive Reflector. 6.4.2 Arbitrary-Angle Frequency Tuned Reflector. 6.4.3 Arbitrary-Angle Electronically Tuned Reflector. 6.5 Two-Dimensional Structures. 6.5.1 Two-Dimensional LW Radiation. 6.5.2 Conical-Beam Antenna. 6.5.3 Full-Space Scanning Antenna. 6.6 Zeroth Order Resonating Antenna. 6.7 Dual-Band CRLH-TL Resonating Ring Antenna. 6.8 Focusing Radiative "Meta-Interfaces". 6.8.1 Heterodyne Phased Array. 6.8.2 Nonuniform Leaky-Wave Radiator. References. 7 The Future of MTMs. 7.1 "Real-Artificial" Materials: the Challenge of Homogenization. 7.2 Quasi-Optical NRI Lenses and Devices. 7.3 Three-Dimensional Isotropic LH MTMs. 7.4 Optical MTMs. 7.5 "Magnetless" Magnetic MTMs. 7.6 Terahertz Magnetic MTMs. 7.7 Surface Plasmonic MTMs. 7.8 Antenna Radomes and Frequency Selective Surfaces. 7.9 Nonlinear MTMs. 7.10 Active MTMs. 7.11 Other Topics of Interest. References. Index.
2,750 citations
TL;DR: A quantum generator for surface plasmon quanta is introduced and the phenomenon of surface Plasmon amplification by stimulated emission of radiation (spaser) is considered.
Abstract: We make a step towards quantum nanoplasmonics: surface plasmon fields of a nanosystem are quantized and their stimulated emission is considered. We introduce a quantum generator for surface plasmon quanta and consider the phenomenon of surface plasmon amplification by stimulated emission of radiation (spaser). Spaser generates temporally coherent high-intensity fields of selected surface plasmon modes that can be strongly localized on the nanoscale, including dark modes that do not couple to far-zone electromagnetic fields. Applications and related phenomena are discussed.
1,701 citations