Metal Strip Research Articles

Temperature-responsive metamaterials made of highly sensitive thermostat metal strips.

Temperature-responsive metamaterials have remarkable shape-morphing ability during thermal energy conversion. However, integrating the thermal shape programmability, wide-working temperature range, fast temperature response, and actuation into metamaterials remains challenging. Here, we introduce using thermostat metal strips to assemble metamaterials with desirable and balanced temperature-responsive properties, and we systematically investigate the thermal deformation performance. Achieving 70 to 80% of the designed strain requires only 5 seconds of heating. A thermal strain of around 30% is achieved for the assembled metamaterials, surpassing other bimetallic metamaterials by a magnitude of 100 to 200. The actuation capacity of thermostat metal strips exceeds 26 times their weight. Further, by leveraging the highly programmable thermal deformation, the tuneable bandgap range is 3847 to 40,000 hertz. These fully integrated mechanical performances in the multiphysics have great application potential, for example, as soft actuators and soft robots in intelligent structure systems, vibration isolation and noise reduction in hypersonic vehicles, and unique thermal deformation in precision instruments.

Design and analysis of response threshold of energy selective surface based on serial LC circuits

Abstract This paper presents a method to design the response threshold (RT) of energy selective surface (ESS) based on series LC circuits (SLC_based_ESS). A simple SLC_based_ESS structure composed of metal strips and PIN diodes is used for demonstration. According to our research, the RT is rarely related to the geometry parameters of unit cells. By contrast, the RT could be designed by introducing auxiliary structures (ASs) to SLC_based_ESS arrays. With the AS, the induced currents on diodes are enhanced and thus RT is greatly reduced. Prototypes are fabricated and measured under different power levels. The results agree well with simulations, proving an effective design of RT by the proposed method.

Crashworthiness and stiffness improvement of a variable cross-section hollow BCC lattice reinforced with metal strips

The ultra-lightweight structures with high mechanical properties and energy absorption behaviors are focused on the innovation structural design. The design strategy of implementing novel unit cells within architecture materials such as lattice materials enables the attainment of unparalleled combinations of mechanical properties and functionalities while minimizing weight. The most common method to design light-weight lattice materials is optimizing the geometric configurations of the unit cells. However, changing the geometric boundary of lattice structures can also be a good solution to improve the mechanical characteristics and energy absorption behaviors of the lattice materials. In this work, a novel variable cross-section hollow (VCH) lattice was established to improve the energy absorption capacity. By adding metal strips on the edge of the VCH lattices, a new reinforced variable cross-section hollow (RVCH) lattice with metal strips was developed to further enhance the stiffness and energy absorption capacity. The stainless VCH and RVCH lattices were additively manufactured by Selective Laser Melting (SLM) using an EP-M450H metal 3D printer. The quasi-static compressive characteristics and energy absorption behaviors of RVCH lattices were studied experimentally. Finite element modeling was implemented to study the energy absorption mechanism of RVCH lattices. A parametric analysis based on the finite element models was conducted to study the influence of different metal strips on the energy absorption capacity of RVCH lattices. The results show that the RVCH lattices with metal strips attaching to the vertical edges can signally enhance energy absorption of lattice structures with good load uniformity. Furthermore, the natural frequencies analysis indicate that the higher bending stiffness and the tensile stiffness can be achieved for RVCH lattices. This novel lattice is more stable as a load-bearing structure and more efficient as an energy absorber, which can provide guidance in designing innovative lattice structures with excellent mechanical properties and energy absorption capacity.

A Wideband High-Gain All-Metal Antenna under Quad Resonances Realized by Folding a Simple Patch

This paper presents a novel wideband antenna with a simple structure comprising an integrated microstrip patch antenna (MPA) and three shorted microstrip patch antennas (SMPAs). These four radiators constitute an antenna that operates under quad resonances and achieves a wide frequency bandwidth. Since all units are electrically connected, the antenna can be easily fabricated by folding a single metallic strip to realize an all-metal antenna structure, leading to enhanced resistance to extreme environmental conditions and lower power loss. An antenna prototype was used to validate the proposed concept. The measurement results indicated that the proposed handmade structure, which employed probe excitation with overall electrical dimensions of 0.29λ × 0.27λ × 0.11λ, can acquire an impedance frequency bandwidth of 67% for <i>S</i><sub>11</sub> ≤ -10 dB from 1.6–3.2 GHz and achieve a maximum boresight gain of up to 10 dB. The wide frequency bandwidth, high gain, and simple structure make this antenna a promising candidate for wideband mobile systems.

A Compact Planar MIMO Inverted‐F Antenna (PIFA) for Sub‐6 GHz 5G Communication and IoT Wireless Networks Applications

ABSTRACTA compact eight‐port MIMO structure containing planar inverted‐F antennas (PIFAs) as radiating elements is designed for 5G cellular communication applications within the sub‐6 GHz band. The proposed antenna consists of four radiating elements that are placed at four corners on the same plane of geometry. The overall dimension of the ground plane is considered to be 59 mm × 120 mm to make it convenient for modern smart mobile handsets. Each radiating element has 2‐feeding plates, which are situated perpendicular to each other in orientation to make the arrangement cross‐polarized, which in turn exploits polarization diversity as well as spatial diversity among the combination of different radiating elements. The patches are structured by embedding rectangular slots in a meandered shape, and the ground plane is configured by introducing rectangular slots and narrow metallic strips. The prototype of the prescribed MIMO PIFA model has been fabricated and experimentally tested. It shows multi‐band operations (3.27–3.37, 4.16–4.35, 4.93–5.06, and 5.47–5.68 GHz) within the sub‐6 GHz spectrum. The isolation among various patches is observed within the range of −35 dB to −42 dB. The peak gain reaches around 8.1 dBi. The designed MIMO PIFA exhibits superior diversity performance by producing ECC ≤ 0.0006, DG ≈ 10 dB, CCL < 0.20 bits/Hz/s, and MEG ≤ −3 dB. Furthermore, the specific absorption rate (SAR) is evaluated according to the standard values of fat, skin, and muscle at 3.3 GHz. The prescribed model maintains acceptable SAR values for 1‐g and 10‐g tissues, which makes it suitable for smartphone applications.

Single layer dual wideband linear to circular polarisation converter with integrated parasitic elements

This paper presents a novel single-layer, single-sided, dual-wideband linear-to-circular (LTC) polarsation converter. The unit cell of the polarisation converter comprises two identical diagonally oriented C-shaped metallic strips arranged symmetrically and integrated with four outwardly extending diagonal parasitic strips. The LTC polarisation converter is placed on the top side of an ultra-thin substrate layer with a profile size of 0.020 λo at 11.9 GHz and 0.05 λo at 30.7 GHz. The inclusion of parasitic strips in the unit cell design is pivotal, inducing a 90º phase shift between the orthogonal wave components, thus enhancing LTC polarisation conversion. The design achieved near-equal transmission amplitudes and maintained a stable phase difference of nearly 90° across two distinct frequency bands, enabling right-hand circular polarisation in the lower frequency band and left-hand circular polarisation in the higher frequency band. Numerical and experimental results showed that the polariser can realise a wideband LTC polarisation conversion for both x- and y-polarised electromagnetic wave incidences at two distinct frequency bands of 6.78–17.08 GHz (fractional bandwidth of 86.3%) and 25.09–36.40 GHz (36.8%). The converter maintained consistent polarisation conversion performance across a broad range of incidence angles and exhibited high and uniform total transmittance in both operational frequency bands.

Effect of High-Velocity Impact Loading on Concrete Slabs Reinforced by Metallic Strips from Soft Drink Cans as Fiber

Effect of High-Velocity Impact Loading on Concrete Slabs Reinforced by Metallic Strips from Soft Drink Cans as Fiber

Generation and tuning of notched bands in wideband THz antennas using graphene/metal strips

Abstract A technique is implemented for obtaining tunable band notch/filtering features in terahertz (THz) monopole wideband antennas. A parasitic metal strip is engraved in the antenna radiator, which creates the band notch characteristics in the wideband response. The tunability of the created notched band can be obtained by engraving a non-resonant U-shaped graphene strip in the radiator. The change in the material properties of the graphene strip alters the nature of field confinement in the antenna structure, enabling tunability in the filtering frequency band. Moreover, multiple notch bands can be obtained by carefully selecting the material of the parasitic element U-shaped graphene strip. Thus, the antenna response can be configured for dual- and triple- band filtering operation by varying the materials used for the strips to obtain band notch operation and a U-shaped graphene sheet.

An ultra-broadband low profile modified chessboard metasurface with improved backscattering reduction

Building upon the concepts of polarization conversion and the mechanism of destructive interference, a single-layered ultra-broadband metasurface for radar cross-section (RCS) or backscattering reduction is proposed in this work. A diffusion-assisted checkerboard metasurface with re-tailored unit cells at the center leads to a significant improvement in the stealth characteristics. For this, a low profile and less complex unit cell is proposed, comprising a long metallic strip along the diagonal and two thin horizontal stubs at the edges. This unique arrangement exhibits more than 90% polarization conversion efficiency from 13.2 to 38.2 GHz. Modifying the geometry of central elements in a conventional checkerboard metasurface achieves a minimum of 15 dB RCS reduction from 10 to 38 GHz. Also, as we ascend the frequency spectrum, the beams are scattered in unintended directions with reduced signal strength. Notably, there is no beam in the boresight direction, as opposed to the conventional chessboard configurations. For off-normal incidences, the metasurface exhibits good angular stability, and a minimum of 10 dB backscattering reduction is maintained up to an incidence angle variation of 60°. The final optimized fabricated prototype exhibits measurement results that agree with the simulation results for normal and wide-angle incidences.

A compact wideband filtering rectangular dielectric resonator antenna with U-shaped metal strips

ABSTRACT In this paper, a compact wideband filtering rectangular dielectric resonator antenna (RDRA) loaded with a pair of U-shaped metal strips is proposed. By using a slot-coupled feeding structure, a rectangular DR with a length–width ratio of 3:1 is selected to combine the resonant frequencies of the TE 111 and TE 121 modes to achieve the passband. Two pairs of transverse branches with different lengths are added to the longitudinal microstrip feeding line, and the TE 111 , TE 11+δ1 , and TE 121 modes are successfully excited to enhance the bandwidth. The short pair of transverse branches can generate a null high-frequency radiation. A pair of U-shaped metal strips is loaded at both ends of the top of rectangular DR, introducing a low-frequency radiation null. Both radiation nulls can be independently adjusted. A pair of rectangular grooves is etched inside rectangular DR to boost the impedance matching level. The proposed filtering RDRA has been fabricated and measured for verification. The measured relative impedance bandwidth is 22.67% (4.34–5.45 GHz). The measured average gain and peak gain are 7.19 dBi and 8.06 dBi, respectively. RDRA filtering has broad application potential in modern communications, such as the N79 band.

Compact Substrate Integrated Waveguide Cubical Dielectric Resonator Antenna for fifth-generation applications

A comprehensive analysis of a wideband Cubical Dielectric Resonator Antenna is presented, specifically designed for 5G-NR wireless communication applications, focusing on the N257, and N258 frequency bands. This antenna exhibits symmetrical radiation patterns, a wider bandwidth, improved efficiency, and substantial gain characteristics. The design employs a low-loss substrate-integrated waveguide structure to enhance gain while reducing cross-polarization effects. This is accomplished through an innovative approach of establishing boundary conditions using copper wire stitching for vias, superseding the conventional soldering iron method, which guarantees minimal radiation leakage, compact dimensions, and reduced losses. The perforated dielectric resonator antenna possesses higher mode excitations, and implementing metallic strips on two resonator surfaces facilitates the simultaneous excitation of fundamental and higher-order modes, thereby yielding a broadband response. The overall dimensions of the antenna are 15.29 × 8.42 × 3.8 mm3(1.3×0.7×0.3)λ03, which facilitates a measured impedance bandwidth of 8.2 GHz, spanning from 24.4 to 32.6 GHz (28.7%), accompanied by a high gain of 8.1 dBi and efficiency levels reaching up to 94%. The prototype is constructed utilizing the standard printed circuit board technique, and simulation outcomes are derived using the High-Frequency Structure Simulator (HFSS).

A compact solid-state high repetition rate trigger based on a spiral generator.

The trigger generator made with a spiral generator (SG) has the advantages of light weight, compact structure, and low cost and has promising applications in the pulsed power field. This paper introduces a compact solid-state high-voltage pulse trigger system based on an improved SG, which has improved repetition rate and lowered the demands for semiconductor switches' maximum current and current rise rate when compared with previous studies. The improvement is achieved by winding outward an additional layer of the passive layer and low-voltage metal strip, which realizes a significant reduction of the peak current and current rise rate of the discharge switch. The final dimension of the trigger is 25 × 10 × 10cm3, excluding the power supply. An experiment carried out in single shot mode shows that the peak value of the output pulse can reach 50kV with a leading edge of 57ns. Repetitive experiments were carried out up to 1kHz, with the peak voltage of the output pulse being 30.5kV, the leading edge being 48ns, and the jitter being 0.84ns. Finally, the generator is used to trigger a gas switch, and it works stably and reliably.

Smart design and additive manufacturing of bending tools to improve production flexibility

For the automotive industry, especially on the part of Tier 1 and Tier 2 suppliers, the future will be about maintaining sovereignty in the form of technology openness and accelerating digitization. The product portfolio, which is generally passed on by OEMs to suppliers for production, often includes body parts that cannot always be manufactured economically with the prevailing production technology. The reason for this is a high diversity of model-variants, which requires smaller batches. To this end, highly flexible large-series production cells for body sheet components that can be scaled in all dimensions are being developed and tested. For the first time, they will make it possible to redesign the process planning in series production on a component-specific basis. The aim is to reduce production costs for new, geometrically different component variants. The basic components of the flexible manufacturing system are, firstly, new flexible forming technologies which have the potential to produce typical vehicle part geometries. Secondly, a process generator develops the corresponding production plan. A digital mapping of the manufacturing processes enables the selection of cost-, efficiency-, flexibility- and resilience-optimized production chains depending on the number of parts. Established manufacturing processes to produce car body components are supplemented in the cell by flexible processes such as 3D swivel bending. As a use case for flexible manufacturing, a concept for Rapid Tooling of 3D swivel bending tools is developed. In the flexible manufacturing system to be developed, a method of a standardized process sequence to produce forming tools within 24 h has been lacking to date. For this purpose, the concept of an automated design is being developed in which a reconfigurable tool body can be sliced into sheet metal stripes The active tool surface is additively manufactured after the tool has been packaged using LMD and adapted to individual requirements. The goal in the application of Rapid Tooling is to reduce lead times and development costs through a largely automated tool design and lead time-optimized manufacturing concept.

Optimization of Mechanical Properties during Cold Rolling and Wrap-Forming for Metal Helical Tubes

The proposed method involves the utilization of a strip roll-forming technique to fulfill the specific requirements for constructing large-scale structures in orbit and space station trusses during extraterrestrial exploration. This involves progressively rolling out a metal strip with an L+V-shaped locking edge through multiple passes of forming rolls featuring different section shapes. The process of helical locking enables the formation of a slender, spiral-shaped tube, which can be utilized for the in-orbit assembly of exceptionally large structures. The proposed approach introduces a two-step optimization method to enhance the maximum stress, equivalent plastic strain, and wrapping torque of roll-forming L+V cross-sections and wrap-forming helical tubes. The optimized sample points in the second step are established based on the optimal roll distance and roll gap obtained in the first optimal step, resulting in the determination of the optimal folding height and V-shaped angle of the L+V strip cross-section after optimization. The design of the strip wrapping configuration that follows is highly dependent on these four parameters.

SUB-6 5G NETWORKS: DESIGN OF BUTTON MUSHROOM MIMO ANTENNA AND IT’S INVESTIGATION

The unlicensed National Information Infrastructure radio band (n77, n78, and n46) is taken into consideration for this research work's "Multiple-input-multiple-output (MIMO)" antenna with dual band features. Gradually, the form design of simple single-patch MIMO antennas gives way to four-element MIMO antennas. Four microstrip antennas are integrated using button-like circular caps on the main patches. Reduced ground is also used in the construction of many band characteristics. Excellent isolation can be achieved by using Rectangular Metallic Strip (RMS). The suggested MIMO antenna has the advantage of covering two significant frequency bands. At 3.07 GHz and 6.31 GHz, the antenna system resonates with a total bandwidth of 2.43 GHz. The antenna design uses a FR4 substrate measuring 35 mm by 49 mm by 1.6 mm in thickness. For simulation purposes, Teflon and a specially made SMA connector with a perfect electrical conductor (PEC) are used to enhance impedance matching. An 8.2 mm feed line with an inset feed is also utilized. Research and investigation are conducted on radiation properties, including mean effective gain, envelope correction coefficient, reflection coefficient, and more. Both the reflection and isolation coefficients have values of less than -10 dB, with the former being less than -15 dB. It is a 16.30 dB increase overall. 5G applications will greatly benefit from having this smaller, four-element MIMO antenna.

Compact dual-band enhanced bandwidth 5G mm – wave MIMO dielectric resonator antenna utilizing metallic strips

A compact dual-band Multiple-Input Multiple-Output Dielectric Resonator Antenna with improved bandwidth for 5G mm-wave applications is presented. Two rectangular DRAs mounted on a substrate backed ground plane are excited by microstrip feed through aperture coupling. Notches cut out from center of the DRAs helps to achieve a dual-band response with improved bandwidth by exciting several modes. The isolation between the DRAs is achieved by appropriately positioning metallic strips on walls on of the DRAs. A dual-band response with enhanced bandwidth and mutual coupling reduction. The impedance bandwidth for the proposed design is between 26.5–30 GHz (12.4 %) and 34.2–40 GHz (15.6 %). The maximum isolation achieved in the lower band is 32 dB and above 45 dB in the upper band. The overall size of the design is 1.88λo x 0.94λo x 0.20λo. The design procedure is described, and the role of decoupling strips are explained. A prototype is fabricated and measured to validate the proposed design.

SUB-6 5G NETWORKS: DESIGN OF BUTTON MUSHROOM MIMO ANTENNA AND IT’S INVESTIGATION

The unlicensed National Information Infrastructure radio band (n77, n78, and n46) is taken into consideration for this research work's "Multiple-input-multiple-output (MIMO)" antenna with dual band features. Gradually, the form design of simple single-patch MIMO antennas gives way to four-element MIMO antennas. Four microstrip antennas are integrated using button-like circular caps on the main patches. Reduced ground is also used in the construction of many band characteristics. Excellent isolation can be achieved by using Rectangular Metallic Strip (RMS). The suggested MIMO antenna has the advantage of covering two significant frequency bands. At 3.07 GHz and 6.31 GHz, the antenna system resonates with a total bandwidth of 2.43 GHz. The antenna design uses a FR4 substrate measuring 35 mm by 49 mm by 1.6 mm in thickness. For simulation purposes, Teflon and a specially made SMA connector with a perfect electrical conductor (PEC) are used to enhance impedance matching. An 8.2 mm feed line with an inset feed is also utilized. Research and investigation are conducted on radiation properties, including mean effective gain, envelope correction coefficient, reflection coefficient, and more. Both the reflection and isolation coefficients have values of less than -10 dB, with the former being less than -15 dB. It is a 16.30 dB increase overall. 5G applications will greatly benefit from having this smaller, four-element MIMO antenna.

Using the Plasma Jet Method to Create Zinc Nanoparticles and Study Their Structural and Optical Properties as an NH3 Gas Sensor

In this work, zinc nanoparticles were prepared using the low-temperature plasma method at different times 3 min, 5 min, 7 min, 9 min, where the initial reactions of zinc lead to the formation of nanoparticles. The metal interacts with the ionized plasma under different conditions and may turn into an oxide such as exposing the sample to air and raising the temperature of the solution a few degrees as a result of high voltage and within a certain range. The atmospheric pressure plasma system acts as the cathode, while the zinc metal strip acts as the anode. A series of techniques were used, including the use of X-ray diffraction (XRD), ultraviolet-visible spectroscopy and scanning electron microscopy (FESEM). The X-ray diffraction results showed that the samples have polycrystalline structures with hexagonal and cubic structures with a time difference, and the X-ray diffraction results showed the conversion of zinc particles into zinc oxides. FESEM images reveal particle size and shape. The ZnO nanoparticles prepared by the mentioned method seem to form different nanoshapes such as starfish and mushroom nanoparticles. The UV-visible results showed that the samples had an energy gap of about 3.4 eV at a time of 3 min, and this value decreases with increasing reaction time. The appearance of zinc oxides increases gradually with the passage of time. These results provide credibility for the fabrication of ZnO nanostructures for use in future gas sensing applications, despite the inhomogeneity of particle size among ZnO particles, the sensor was also fabricated to detect nitrogen gas (NH3) with different concentrations (17.25 ppm, 46.38 ppm, 78.58 ppm). at room temperature. The ZnO sample showed the highest sensitivity (88.1%) at 7 min. The sensitivity showed different results and increased with reaction time and gas concentration. However, response and recovery time are moderate and decrease as reaction time increases.

Monolithically integrated EP-based optical isolator.

Exceptional points (EPs) display peculiar degeneracies, where complex eigenvalues and associated eigenvectors coalesce simultaneously, resulting in a defective Hamiltonian. Meanwhile, the negative imaginary part of the energy eigenvalues related to a finite spectral linewidth at the resonant energy, which could provide a solution to tackle the isolation bandwidth limitation of MRR-based optical isolators without sacrificing the insertion loss. Here, a second-order EP2 system constructed by SiN-based cascaded racetrack resonators is proposed, while the metal strip operating as an integrated electromagnet provides magnetic fields required for non-reciprocal phase shifting (NRPS). Owing to the existence of the NRPS perturbation, the system is pushed away from EP and consequently triggers complex frequency splitting, resulting in the isolation bandwidth proportional to the square-root perturbation instead. The results show that the isolation bandwidth of the EP isolator is increased by 163% and 22% compared to single-racetrack and cascaded-racetrack isolators with 2.85 dB insertion loss and 34.3 dB isolation ratio, respectively. The presented EP-based optical isolator shows tremendous potential for high-density monolithic integration and packaging.

Multi-stopband filter based on frequency selective surface

This paper presents the design of a terahertz multi-stopband filter based on a metasurface structure which consisting of multiple metallic strips. By adjusting the dimensions and arrangement of these metallic strips placed on a dielectric substrate, the precise control of the filter performance is achieved. This structure exploits the electromagnetic resonances of metallic strips at terahertz frequencies to generate stopbands, thereby enabling selective filtering. Numerical studies demonstrates that these configurations can produce multiple stopbands within the 4.2 to 15.5 THz frequency range, with tunable center frequencies and bandwidths. Through the research of the transverse and longitudinal filter model structure, the band-stop filter with more stopbands can be realized, and the transmission valley value is kept within 5 %, which is crucial for enhancing filter performance. Moreover, the study reveals that tuning the dimensions of the metallic strips can modulate the resonances, resulting in a redshift of the filter's central frequency and an expansion of the passband width. These findings provide a new method for the performance improvement of terahertz filters, advanced filtering technology and electromagnetic wave control technology.