Narrow Metal Strips Research Articles

Enhancement of magnetic field intensity with a left-handed metamaterial tunnel resonator for obstacle sensing

A narrow metal strip inspired by the left-handed metamaterial and sensitive LC resonator structure has been released in this work where the narrow metal strip is presented as a tunnel structure which can enhance electric and magnetic properties. A commercially available electromagnetic simulator CST Microwave Studio is utilized to design and investigate the eSRR (electric split-ring resonator) and tunnelled LC resonator structures. Furthermore, ADS (Advance Design software) is used to determine the scattering parameters of the equivalent circuit. The proposed metamaterial structure is employed as a sensor operating in the C-band (6.88 GHz) of the microwave region, and its sensing properties are tested using glossy paper as an obstacle. The designed metamaterial tunnelling structure exhibits very high sensitivity toward dielectric obstacles at different rotational angles and thus can be potentially used in various sensing applications. The field enhancement effects on sensing application are verified by measured obtained results for eSRR and tunnelled LC resonator structures.

Open-Stopband Suppression via Double Asymmetric Discontinuities in 1-D Periodic 2-D Leaky-Wave Structures

A technique for the open-stopband (OSB) suppression in one-dimensional (1-D) periodic leaky-wave antennas based on a double asymmetric series/shunt discontinuity inside the unit cell is discussed and applied to a canonical 2-D structure. A longitudinal equivalent network formalism is developed here to analyze the unit-cell matching, which confirms that the OSB suppression cannot be achieved using a double symmetric discontinuity. Conversely, an infinite number of matched configurations can be obtained using two unequal passive discontinuities, whose reciprocal distance can be chosen freely inside a continuous range always including a quarter wavelength. The possibility of suppressing the OSB is then shown for both TM and TE leaky modes supported by a metal strip grating on a grounded slab by using independent full-wave modal solvers and considering typical geometries with either narrow metallic strips or narrow slots inside the unit cell.

Quantum Regime of a Two-Dimensional Phonon Cavity.

We realize the quantum regime of a surface acoustic wave (SAW) resonator by demonstrating vacuum Rabi mode splitting due to interaction with a superconducting artificial atom. Reaching the quantum regime is physically difficult and technologically challenging since SAW devices consist of large arrays of narrow metal strips. This work paves the way for realizing analogues of quantum optical phenomena with phonons and can be useful in on-chip quantum electronics.

Differential surface plasmon polaritons transmission line with controllable common mode rejection

In this paper, a spoof surface plasmon polarions (SPPs) transmission line is designed by patterning thin metal film in open-cross shape arranged in array. Numerical simulations show the proposed open-cross array can support spoof SPPs with enlarged propagation constant and hence enhanced confinement at metal/dielectric interface as compared to the reported ultra-thin plasmonic waveguide with the rectangular groove or solid-cross. Furthermore, a differential transmission line pair is built with such two close plasmonic arrays. A narrow metal strip locates at the symmetrical plane of the two SPPs waveguides and acts as a resonator to realize common-mode rejection at specific frequency. The notch frequency for common mode can be adjusted by tuning the metal strip length of the resonator while differential mode propagation remains unaffected. Both simulated and experimental results with good agreement are given to verify the proposed idea.

Rapid Control Prototyping in Cold Rolling using Piezoelectric Actuators

Precise manufacturing of cold rolled, thin, and narrow metallic strips has become more important for various applications. The overall aim is the reduction of thickness tolerances of steel and copper strips to an extent of less than 1 um. To reach that goal, an experimental rolling mill is set up in which supplementary piezoelectric stack actuators are integrated. The setup of the machine is presented. It contains a real-time system for rapid control prototyping using model-based development. It enables a direct download of a controller from the simulation environment to the machine. Furthermore, bandwidth requirements for the actuators are derived from strip measurements and machine properties. The bandwidth of the actuators is identified by modeling the system's dynamics. The comparison of both actuators reveals that their complementary characteristics are suitable to compensate occurring disturbances.

Polarization-dependent thin-film wire-grid reflectarray for terahertz waves

A thin-film polarization-dependent reflectarray based on patterned metallic wire grids is realized at 1 THz. Unlike conventional reflectarrays with resonant elements and a solid metal ground, parallel narrow metal strips with uniform spacing are employed in this design to construct both the radiation elements and the ground plane. For each radiation element, a certain number of thin strips with an identical length are grouped to effectively form a patch resonator with equivalent performance. The ground plane is made of continuous metallic strips, similar to conventional wire-grid polarizers. The structure can deflect incident waves with the polarization parallel to the strips into a designed direction and transmit the orthogonal polarization component. Measured radiation patterns show reasonable deflection efficiency and high polarization discrimination. Utilizing this flexible device approach, similar reflectarray designs can be realized for conformal mounting onto surfaces of cylindrical or spherical devices for terahertz imaging and communications.

Design, fabrication, and measurement of highly sub-wavelength double negative metamaterials at high frequencies

In this paper, a highly sub-wavelength double negative (DNG) metamaterial for operation at high frequencies is designed, fabricated, and measured. A dual layer design that consists of a planar spiral on one side and a meander line touching with narrow metallic strips on the other side produces the properties of effective negative permittivity and permeability simultaneously, i.e., negative refractive index (NRI). The size of the unit cell of DNG metamaterials is about 253 times smaller than the operation wavelength at 15.2 MHz. The strong coupling between the topological structures on two sides makes a contribution to the miniaturization of the proposed metamaterials. A simple probe method is used to measure the transmission and reflection coefficients, and the comparison of effective medium parameters retrieved from transverse electromagnetic waveguide simulation and the probe method is given to verify the effectiveness and correctness. The measured results from one cell show a good agreement with simulated results. The measured effective real index of refraction n = −6.9 with a total loss that is less than 0.45 dB/cm at 15.2 MHz. The NRI bandwidth was > 10% in the neighborhood of 15.2 MHz.

EXPERIMENTAL STUDY OF EFFICIENT WIRELESS POWER TRANSFER SYSTEM INTEGRATING WITH HIGHLY SUB-WAVELENGTH METAMATERIALS

In this paper, an e-cient wireless power transfer (WPT) system integrating with highly sub-wavelength metamaterials is proposed. The negative refractive index (NRI) and negative permeability (MNG) metamaterials for operation at radio frequencies are designed and applied to WPT system for improvement of power transfer e-ciency. A dual-layer design which consists of a planar spiral on one side and a meander line touching with narrow metallic strips on the other side produces the properties of efiective negative permittivity and permeability simultaneously, i.e., negative refractive index. In addition, the structure of double spirals produces a negative permeability. The cell size of the NRI and MNG metamaterials is about 253 times smaller than the operation wavelength. By integrating one, two, three or four metamaterial slabs between the two coupling copper rings, the transfer e-ciency is improved signiflcantly. The measured results show that the contribution of high transfer e-ciency is due to the property of negative permeability which can make the WPT system work in the mechanism of magnetic resonance.

Dispersive Delay Lines Based on the Use Of Narrow Open Metal Reflectors and Fan-Shaped Transducers

An in-line dispersive delay line (DDL) demands low and controllable reflectivity of the reflectors, especially if the surface acoustic wave (SAW) propagates all the way along the reflecting structure. The metal reflectors are usually too strong and introduce too much attenuation in such a device. The proposed solution of this problem is to spatially separate the acoustic channels for different frequencies with the help of Fan-shaped Transducers (FIDT) and to use narrow open metal reflectors to reduce reflectivity. Special arrangement of FIDT is performed to use 180-deg. reflection of the SAW. Narrow open metal strips with a metallisation ratio of the order of 20% are used as reflectors with small and controllable reflectivity. Reflectivity of such strips is estimated both theoretically and experimentally. Experimental performance of the proposed DDL is presented.

Wire Flattening Using a Ball Rolling Mill

AbstractIncreasing requirements towards narrow and thin strips necessitates research concerning technology improvements and changes in construction of flattening devices. Wire flattening between the balls is an efficient manufacturing method of thin and narrow strips made of steel non‐ferrous metals and their alloys. The study presents an analysis of the effect of flattening process in a ball rolling mill on widening of X10CrNi 18‐8 steel wire. Performed tests proved that flattened strips feature uniform thickness throughout their width, narrow dimensional tolerance and high surface quality. This innovative method of wire flattening in a ball rolling mill means a step ahead in the development of production technologies of extremely narrow and thin metal strips for many modern applications.

Assessment of the Performance of a Metamaterial Spacer in a Closely Spaced Multiple-Antenna System

A metamaterial spacer composed of spiral resonators (SRs) and narrow metal strips has been tested to operate like a bidirectional artificial magnetic conductor (AMC) reflector at 2.45 GHz. The performance of the spacer has also been evaluated in a closely spaced multiple-antenna system applied to successfully increase the transmission capacity of a commercial wireless IEEE 802.11b router.

One-dimensional plasmons in ultrathin metallic silicide wires of finite width

The acoustic dispersion of plasmons (PLs) in narrow (4 nm) and ultrathin (one unit cell) metallic ${\text{DySi}}_{2}$ wires, grown by self-assembly on vicinal Si(100)-[011] $4\ifmmode^\circ\else\textdegree\fi{}$ turns out to be unidirectional. We observed the lowest intersubband PL as well as the acoustic PL. These PLs are specific for narrow metallic strips of finite width. Our experimental and theoretical analysis suggests that only one of two electron pockets in the surface Brillouin zone makes a substantial contribution to the PLs because the other pocket has a much smaller conductive character due to a strong admixture of electronic states with $d$ character.

DESIGN, FABRICATION AND CHARACTERIZATION OF A DIELECTRIC RESONATOR ANTENNA REFLECTARRAY IN KA-BAND

A new re∞ectarray conflguration is proposed for low-loss applications at millimeter waves. It is based on the use of dielectric resonator antennas (DRA) as radiating unit-cells. The phase response of the elementary cell is controlled by adjusting the length of a parasitic narrow metal strip printed on the top of each DRA. A 330 - phase dynamic range is obtained for DRAs made in rigid thermosetting plastic (r = 10). As the antenna radiating aperture is non ∞at, an original low-cost fabrication process is also introduced in order to fabricate the parasitic strips on the DRA surface. A 24 £ 24- element array radiating at broadside has been designed at 30GHz and characterized between 29 and 31GHz. The antenna gain reaches 28.3dBi at 31GHz, and the measured i1dB-gain radiation bandwidth is 5.2%. The 3.2dB loss observed between the measured gain and theoretical directivity is mainly due to the spillover loss (2.3dB). The total dielectric and conductor loss is less than 0.9dB.

Truncation effects in a semi‐infinite periodic array of thin strips: A discrete Wiener‐Hopf formulation

A rigorous solution for the current induced on a semi‐infinite array of narrow metallic strips is obtained using the Wiener‐Hopf factorization method in the Z‐transformed domain. The method can be applied to arrays with fixed current shape on each element (e.g, single mode elements), and shows rigorously the physics of waves associated to truncated periodic structures. The solution is obtained via a rigorous factorization, that is improved by using a closed form result based on an approximated factorization. The current on the truncated array is rigorously represented as the sum of the current pertaining to the infinite array plus a contribution induced by the truncation of the array. Asymptotics shows that the truncation‐induced current contribution has a diffractive behavior decaying algebraically with the element number, away from the truncation. Uniform asymptotics shows that this diffractive current is effectively represented in terms of Fresnel functions, permitting also a closed form representation in proximity of and at transverse inward resonance, i.e., when a grazing grating lobe points toward the array. Illustrative examples and comparisons with a method of moment solution show the accuracy of our results.

Internal DTV antenna for folder‐type mobile phone

AbstractBy using the upper and lower ground planes of a folder‐type mobile phone, a novel internal shorted dipole antenna for digital television (DTV) signal reception in the 470–806‐MHz band is presented. The shorted dipole antenna further comprises an internal matching circuit, which includes a chip capacitor and two narrow metal strips, for achieving improved impedance matching over the DTV band of 470–806 MHz. The proposed DTV antenna was constructed and studied. The measured return loss for the operating frequencies over the DTV band is better than 2.5:1 VSWR. In addition, good radiation characteristics are also obtained. Design considerations of the proposed internal DTV antenna are described. A parametric study of the internal matching circuit on the impedance matching of the antenna is also presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1015–1019, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21587

Superconducting fluctuations in one dimension

We review recent experimental studies of superconductivity in one dimension; i.e., in very narrow metal strips and wires. Such systems were first studied many years ago, and it was found that thermally activated phase slip leads to a nonzero resistance even below T c. In the past several years, experiments by several groups have provided evidence for another phase slip mechanism. These new experiments are described and shown to be consistent with a model based on quantum phase slip, i.e., tunneling through the energy barrier for phase slip. Unresolved issues associated with the model are also discussed.

On the modeling of metal strip antennas contiguous with the edge of electrically thick finite size dielectric substrates

A solution to the problem of radiation by a narrow metal strip antenna contiguous with the edge of a dielectric substrate is presented where the substrate has parameters such that its electrical thickness is appreciable. Such an antenna may be useful at millimeter wavelengths as an integrated phased array element forming a part of a monolithic microwave integrated circuit (MMIC). A suitable geometry for this application is illustrated and an efficient computational procedure developed. Comparisons with experimental results for the input impedance and far-field radiation patterns show excellent agreement. The influence of the dielectric substrate on the performance of an antenna designed to operate at approximately 60 GHz is discussed. Two examples, the first involving the analysis of a coplanar strip transmission line fed antenna and the second involving impedance matching and control of cross-polarized radiation using a folded strip dipole, are given to illustrate practical applications of the analytical method to design problems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Problem of localization and scattering of the conduction electrons at the rough metal surface

The localization in 2D-electron system induced by surface scattering is investigated. The localization length and the averaged coductance of a narrow metal strip are obtained. For a thick sample we have derived and analysed the boundary condition for quasiclassical electron distribution function under the arbitrary values of Rayleigh parameter.

Recognition of spatial parameters by echolocation in the vampire bat,Desmodus rotundus

Three vampire bats (Desmodus rotundus) were trained in a two-choice apparatus (Fig. 1) to select the one of two passages that contained a vertical stick or narrow metal strip at a distance of 45 cm. To single sticks in isolation they responded at a width of 1.1 mm or more. Large surfaces in the vicinity of the target impaired the locating ability; the animals correctly choose a 20-mm-wide strip 2.5 cm in front of a strongly reflecting plate (Fig. 2) or 6 cm away on one side of it (Fig. 3).

Flashover across the surface of an electrolyte: arresting arc propagation with narrow metal strips

Flashover across the surface of an electrolyte: arresting arc propagation with narrow metal strips