Strip Conductor Research Articles

Electromagnetic Stress Analysis of High-Temperature Superconducting Coated Conductor Strip After Partial Debonding at the Edge Under the Combined Transport Current and Magnetic Field

Electromagnetic Stress Analysis of High-Temperature Superconducting Coated Conductor Strip After Partial Debonding at the Edge Under the Combined Transport Current and Magnetic Field

Ultra-Wideband Common-Mode Rejection Structure with Autonomous Phase Balancing for Ultra-High-Speed Digital Transmission.

For ultra-high-speed digital transmission, required by 5G/6G communications, ultra-wideband common-mode rejection (CMR) structures with autonomous phase-balancing capability are proposed. Common-mode noise, caused by phase and amplitude unbalances, is one of the most undesired disturbances affecting modern digital circuits. According to the circuit design guides with a typically used differential line (DL) for high-speed digital transmission, common-mode rejection is achieved using CMR filters, and the unbalanced phase, caused by a length difference between the two signal lines of a DL, is compensated by inserting an additional delay line. However, due to nonlinear phase interactions between the two DLs and unbalanced electromagnetic (EM) interferences, the conventional compensation method is frequency-limited at around 10 GHz. To significantly enhance the common-mode rejection level and extend the phase recovery bandwidth, the proposed CMR structure utilizes a planar balanced line (BL), such as a coplanar stripline (CPS) or a parallel stripline (PSL), along with additional conductor strips arranged laterally near the BL. To demonstrate the performance of the proposed BL-based CMR structures, various types of CMR structures are fabricated, and the measurement results are compared with the 3D EM simulation results. As a result, it is proven that the proposed BL-based CMR structures have the capability to reject the common-mode noise with suppression levels of more than 10 dB and to simultaneously recover the phase balance from near DC to over 40 GHz.

SCATTERING OF THE E-POLARIZED ELECTROMAGNETIC WAVE BY SOLITUDE CONDUCTIVE STRIP WITH IMPEDANCE

The key problem of scattering of a plane E - polarized electromagnetic wave by a solitude electrically conductive impedance strip is studied in detail. A well-posed full-wave mathematical model of scattering in the form of the first order singular integral equation was obtained by applying a modifica- tion of a classical method if integral equations. To examine this singular integral equation two basic methods were used. The first one is remarkable Lord Rayleigh’s asymptotic method, which delivers an explicit analytical solution in a narrow frequency range. It deals with the long-wave case of the plane E - polarized electromagnetic wave scattering problem. The second method is a direct numerical method, dealing with approximate computa- tion of definite integrals, which gives an approximate solution as well, but in the full-frequency range. A series of numerical experiments on scattering a E-polarized electromagnetic wave by impedance strip were carried out and are presented in this paper. Comparing of computation results shows good agreement in long-wave case of the plane E - polarized electromagnetic wave scattering problem, which indicates the correctness of numeric compu- tation in full frequency range as well.

The DUNE Far Detector Vertical Drift Technology. Technical Design Report

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including themystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model.The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolutionrequired to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise.In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D.Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered.This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals.

Development of AgNPs-PVP/TPU based flexible strain sensors for structural health monitoring of composite structures

Real-time in-stu structural health monitoring (SHM) of composite structure developed through highly sensitive and flexible smart sensors based on colloidal solution of Silver Nano Particles (AgNPs). Synthesis of AgNPs through chemical reduction method by citrate and then in Haxen phase transferred by using surfactant Cetyltrimethylammonium bromide (CTAB). Colloidal solution of AgNPs-Haxen and Polyvinylpyrrolidone (PVP) - Haxen has been followed by mixed, calcined and deposited that thick paste on flexible Thermoplastic Polyurethane (TPU) film. These sensors become more sensitive than metallic foil made sensors and farther this sensor pasted on polymer composite for monotonic loading like tensile loading. The data extracted from sensors was monitored effectively by data acquisitioning technique using Keithley KUSB-3100. This research based on chemical synthesis of metallic nanoparticles like silver, its functionalization, protection of these nanoparticles from environment by capping agents and by creating inert atmosphere respectively. Then these functionalized capped nanoparticles are embedded on the surface of thermoplastic Urethane (TPU) film to make piezo resistive semi conductive strips which serve as flexible strain gauge/smart sensor. One other technique is also being used to make sensor is that colloidal solution of metallic Nanoparticles sprays over TPU substrate using Connective Self Assembly (CSA) method. The sensor then properly attached to Glass fabric reinforced polymer (GFRP) composite and calibrated using data acquisitioning (DAQ) under different mode of testing.

SPRISS: Scalable and precise resistive impact sensor for smallsats, architecture description and tests

Space debris are a tangible risk for satellites in Earth orbits. Indeed, in the last decades fragmentation events have generated a large number of uncontrolled objects that have made the debris population grow. Modelling the space debris environment is becoming a fundamental task to evaluate the vulnerability of operational satellites, the probability of accidental collisions with uncontrolled objects, and the evolution of the debris population. With this aim, remote and in-situ measurements provide valuable data to tune the space debris population models and improve their reliability. While large satellites can be observed and tracked from ground, the sub-millimeter debris population requires in-situ measurements. In this context, in-orbit impact sensors are a key technology to obtain information about the sub-mm space debris environment. In this framework, a small-scale impact sensor sized to be integrated in a 2U CubeSat is being developed at the University of Padova. The sensor consists of a multitude of thin, conductive stripes arranged on a thin film of non-conductive material. When a debris hits the sensor, one or more stripes are severed, and the impact is detected. Moreover, the sensor design ensures low power consumption, making it feasible for CubeSat space missions. This work presents the latest outcomes obtained from the development of the sensor. Specifically, structural analyses are performed to assess that the sensor can withstand the launch loads, as well as thermal analyses to confirm its endurance capability with in-orbit temperatures. The number of expected impacts during the mission is predicted through orbital propagation, using state-of-the-art debris environment modelling tools. Finally, the paper presents a functional shooting test and vibration tests, executed onto a development model of the sensor, which verify its functionality and validate a Technology Readiness Level (TRL) of 4.

Performance analysis of quad-port UWB MIMO antenna system for Sub-6 GHz 5G, WLAN and X band communications

A quad-port Multiple Input Multiple Output Antenna with high isolation is presented in this paper. The MIMO design is intended to receive Ultra-Wide Band response to target various wireless applications. The engineered model has 40 x 40 × 1.6 mm3 electrical dimensions. A single antenna achieves size compactness due to an appropriate inclusion of vertical and horizontal conductive strips. Additionally, a diagonal radiating strip is shaped and pooled with the patch geometry. A similar design is positioned orthogonally with each other to receive diversified performance. The four conducting ports are positioned with an appropriate minimum distance to lower down the possible mutual coupling. A partial ground plane having border geometry has been incorporated to receive the ultra-wide band response. An additional plus-sign shaped conducting strips are provided and united with ground lines for isolation enhancement. The MIMO system exhibits ultra-wide frequency response from 3.20 GHz to 13.40 GHz with adequate isolation below −20 dB and an impedance bandwidth of 10.20 GHz. The proposed structure provides an overall gain of 2 dBi having above 80 % efficiency. The presented radiator exhibits excellent MIMO diversity response achieving minimal mutual coupling effect. The other output parameters such as envelope correlation coefficients<0.05, diversity gain of nearly 10 dB, mean effective gain<0.2 dB, and channel capacity loss<0.1 bits/sec/Hz were obtained. The proposed design has been simulated in High Frequency Structure Simulator (HFSS) software. The developed MIMO antenna has been analyzed through VNA N9912A. An encouraging correlation between the software generated and actual responses was observed. The strong agreement between actual results and software results shows the design potential for wireless communications. The highly isolated MIMO system registers its potential for sub-6 GHz 5G, WLAN, and X Band communications.

Smart Hydrogel Swelling State Detection Based on a Power-Transfer Transduction Principle.

Stimulus-responsive (smart) hydrogels are a promising sensing material for biomedical contexts due to their reversible swelling change in response to target analytes. The design of application-specific sensors that utilize this behavior requires the development of suitable transduction concepts. The presented study investigates a power-transfer-based readout approach that is sensitive to small volumetric changes of the smart hydrogel. The concept employs two thin film polyimide substrates with embedded conductive strip lines, which are shielded from each other except at the tip region, where the smart hydrogel is sandwiched in between. The hydrogel's volume change in response to a target analyte alters the distance and orientation of the thin films, affecting the amount of transferred power between the two transducer parts and, consequently, the measured sensor output voltage. With proper calibration, the output signal can be used to determine the swelling change of the hydrogel and, consequently, to quantify the stimulus. In proof-of-principle experiments with glucose- and pH-sensitive smart hydrogels, high sensitivity to small analyte concentration changes was found along with very good reproducibility and stability. The concept was tested with two exemplary hydrogels, but the transduction principle in general is independent of the specific hydrogel material, as long as it exhibits a stimulus-dependent volume change. The application vision of the presented research is to integrate in situ blood analyte monitoring capabilities into standard (micro)catheters. The developed sensor is designed to fit into a catheter without obstructing its normal use and, therefore, offers great potential for providing a universally applicable transducer platform for smart catheter-based sensing.

Dual-Channel Transverse Fields Radiofrequency Coils for 1.5 T Magnetic Resonance Imaging.

This theoretical study presents the design and analytical/numerical optimization of novel dual-channel transverse fields radiofrequency (RF) surface coils for 1.5 T Magnetic Resonance Imaging (MRI). The research explores a planar setup with two channels on a row with aligned spatial orientation of the RF coils, aiming to solve a common design drawback of single-channel transverse field RF coils: the reduced Field Of View (FOV) along the direction of the RF field. A significant challenge in this design is the efficient decoupling of two sets of transverse field RF coils to prevent mutual interference. Our modeling approach integrates thin wire theoretical modeling, magnetostatic computation for strip conductor coils, and their full-wave electromagnetic simulation. Key findings at 64 MHz demonstrate that strategic geometric placement among the two-channel RF coil and the introduction of geometrical asymmetry in the design of the individual RF coils does minimize the mutual inductance, paving the way for effective dual-channel MRI applications. This decoupling approach allows to enhance the FOV, providing a theoretical framework for the development of optimized dual-channel transverse field RF coil configurations. The current design was validated with full-wave numerical study at 64 MHz (1H, 1.5 T), has the potential to be extended at lower or higher frequencies, and the presence of lossy samples needs to be considered in the latter case.

A new deformable self-clinching fastener

This work proposes a novel deformable self-clinching fastener for producing hidden lap joints suitable for both structural and electric power distribution applications. The fastener, characterized by an axisymmetric concave shape, is employed to fabricate hybrid busbar joints between electrically conductive strips of different materials and thicknesses. The self-clinching process with the new deformable fastener involves machining dovetail holes in both conductors and applying a squeezing force to the fastener to create a form-closed mechanical joint. The work encompasses both experimental investigations and numerical modeling using finite element analysis and is carried out on unit cells made from aluminum and copper conductors, which are representative of the joining process. The investigation evaluates force requirements, conducts destructive testing, and performs thermo-electric characterization of the new joints to conclude on the suitability of the new deformable self-clinching fastener for electric power distribution applications. Results indicate that while copper fasteners necessitate greater squeezing forces, they offer superior mechanical and thermo-electrical performance compared to aluminum fasteners in hybrid busbar joints.

Analytical Solution of Eddy Current in Parallel Conducting Strips for Low-frequency Shielding Purposes

In instrumentation systems, shielding is the main issue that judges the performance of the system. The electromagnetic (EM) noise may affect the performance of the instrumentation system if inadequate protection is reached. It is considered the main source of unprotectable interference that may affect these systems in many cases. In this paper, shielding is attained by wrapping the source carrying signal with periodic thin conductive strips separated by slots or openings. This arrangement will protect the sources from the outside EM fields. Shielding factor and shielding efficiency are studied by extracting magnetic fields. For this purpose, an analytical solution based on solving Laplace’s equation for the magnetic vector potential in the region of interest is presented. A closed form of the induced eddy current in the conductive strips is calculated based on Fourier series expansion. Furthermore, numerical simulation using the commercial software MWS CST is employed to validate the analytical solution. The performance of the proposed shielding structure is studied and analyzed in terms of shielding factor and shielding efficiency. The outcomes of both methods are showing very good agreement.

Analysis of Varying Temperature Regimes in a Conductive Strip during Induction Heating under a Quasi-Steady Electromagnetic Field

Transition processes in a steel conductive strip are analyzed during its induction heating under a quasi-steady electromagnetic field. In particular, the temperature field in the strip is studied. A method of solving corresponding initial boundary problems in a two-dimensional mathematical model for differential equations of electrodynamics and heat conduction is developed. The Joule heat and the temperature are determined with a high level of accuracy. The defining functions are the temperature and component of the magnetic field intensity vector tangent to the bases and end planes of the strip. To find them, we use cubic approximation of the defining functions’ distribution along the thickness coordinate. The original two-dimensional initial boundary value problems for the defining functions are reduced to one-dimensional initial boundary value problems on their integral characteristics. General solutions for these problems are obtained using the finite integral transformation by the transverse variable and the Laplace transform of the integral by time. Integral characteristics’ expressions are represented as convolutions for functions that describe homogeneous solutions of one-dimensional initial boundary value problems and limiting values of defining functions on the bases and end planes of the strip. The change of temperature under a varying regime in the dimensionless Fourier time and temperature distribution over the strip cross-section in a steady state depending on the parameters of induction heating and the Biot number are numerically analyzed. Varying and constant temperature regimes of the strip under conditions of the near-surface and continuous induction heating are studied.

The characteristic impedance calculation method of microstrip line and application in embroidered microstrip line

Presently, it is difficult to measure the characteristic impedance of embroidered microstrip line for its conductive anisotropy directly. The published work had proposed to use S-parameters to estimate the port impedance of a balanced dipole antenna, and it cannot be used to calculate the characteristic impedance of microstrip lines with one arm. Thus, it is still a problem on measuring and obtaining 50 Ω characteristic impedance of embroidered microstrip line. Therefore, taking the reflection coefficient as an intermediate variable, this work proposes to use return loss [Formula: see text] to derive the expression of the characteristic impedance of microstrip line. Combined theoretical calculation with experimental testing on characteristic impedance of the fabric-based microstrip line, the expression of the characteristic impedance was verified. Then, the expression of the characteristic impedance of microstrip line was used to calculate the characteristic impedance of embroidered microstrip line and determine its equivalent substrates. The results show that the fabric embroidered with a single-layer conductive strip is a part of its equivalent substrate, and the fabric embroidered with a double-layer conductive strip is not a part of its equivalent substrate.

Intermediate annealing and strong cube texture of Ni-5at.%W alloy thin substrates for YBCO coated conductors

In this work, a series of studies have been carried out on ultra-thin Ni-5at%W (Ni5W) alloy substrates used for the coated conductors. The ultra-thin Ni5W alloy substrate can be fabricated for the large square REBCO film with a size of over 40 mm × 40 mm, which is normally used in scenarios to support a magnetic field in a specific area. To obtain a stronger recrystallized cubic texture, the intermediate annealing was added to optimize the rolling texture during the rolling process of the Ni5W alloy substrate. A typical copper-type rolling texture was obtained in the substrate which intermediate annealed at 96.25%, and the cube texture reached 97.6% after annealing recrystallization. Moreover, The deformation and recrystallization of 40 μm thick Ni-5at%W (Ni5W) alloy thin substrates were investigated by the quasi-in situ method. The fabrication of ultra-thin Ni5W substrates increases the potential of miniaturizing lightweight coated conductors, which helps to further promote and accelerate the manufacturing process of the entire coated conductor strip.

A Compact Low-Profile Vertically Polarized Endfire Leaky-Wave Antenna Based on Double-Sided Parallel Strip Line

This article presents a vertically polarized (VP) endfire leaky-wave antenna (LWA) on a low-profile substrate by loading a series of shorting pins and slots along the double-sided parallel strip line (DSPSL). The periodically loaded shorting pins act as the VP radiator elements of the antenna, and also have the function to make the normalized phase constant of the original DSPSL equal to one so as to meet the endfire radiation condition. A series of slots etched on strip conductor around shorting pins are utilized to improve the radiation efficiency of the antenna in addition to its vertical polarization. In this way, the VP endfire LWA can be eventually realized with efficient radiation on a low-profile substrate. In our design, the mechanism of the proposed antenna is first analyzed based on the equivalent circuit model to investigate the effects of pins and slots on the antenna operation. Then, the attenuation properties of the antenna are detailly discussed under various structural dimensions to explore the relation between its physical sizes and radiation capability. Finally, a prototype is designed and fabricated to verify the predicted properties. The measured results match well with the simulated ones, thus demonstrating and confirming that the proposed endfire LWA can indeed realize efficient radiation with vertical polarization based on a single low-profile substrate.

Donbas conductivity anomaly in the Karpinsky Swell

Donbas Foldbelt (DF) and Karpinsky Swell (KS) are contiguous parts of a system of elongated sedimentary basins forming lineament from Poland through Pripyat Trough in Belarus, the Dnieper-Donets Basin (DDB) and DF in Ukraine, KS in Russia, across the Caspian Sea, through Mangyshlak in Turanian plate in Asia. In DF, the Mesozoic-Cenozoic sediments were raised, and subsequent erosion exposed the Carboniferous coal-bearing strata. In contrast to DF, the Paleozoic rocks in KS are covered by 1—3 km thick sediments of Mesozoic-Cenozoic age; productive structures of the earlier age cannot be confidently studied in KS by geological methods. So, geophysical methods are the promising approach for the KS deep structure studies. This work is devoted to electromagnetic (EM) studies of the electrical conductivity of rocks by the methods of magnetic variation profiling (MVP) and magnetotelluric sounding (MTS). Previously [Rokityansky, Tereshyn, 2022], we described the results of the EM research on DF in detail. MVP reveals the intense Donbas electrical Conductivity Anomaly (DCA) running along the main anticline of the folded Donbas. DCA parameters: maximum possible depth of the anomalous currents center h=18±2 km. Frequency response maximum Т0≈3600 s yields the total longitudinal conductance G=(8±2)∙108 S∙m. 70 MTS at periods 0.1—3000 s yield two conductive stripes, with the upper edge varying from 0.3 to 5 km. The stripes are parallel to the DCA axis and are considered as part of DCA. A very large value of G suggests that the anomalous body extends to some considerable depth. The DCA axis spatially coincides with an intense (up to 90 mW/m2) deep heat flow anomaly. Thus, the nature of the DCA lower part can be a partial melting. Theoretical estimates show that intense anomalous fields of geomagnetic variations arise over highly elongated conductors. Therefore, there is reason to expect that the anomaly continues eastward. We found two MTS profiles crossing the Karpinsky swell, and under both profiles strong conductivity anomalies are clearly seen. We re-interpreted original data and presented parameters of all 3 anomalies in an identical style. The main conclusion: the anomaly parameters on the three profiles are approximately the same, and one can assume with a high probability the existence of a single anomaly of electrical conductivity in the Donbas and Karpinsky Swell with a common length of more than 500 km and longitudinal conductance G≈8×108 S×m.

Interfacial Shearing and Transverse Normal Stress in a Superconducting Coated Conductor Strip with Combined Transport Current and Magnetic Field

Interfacial Shearing and Transverse Normal Stress in a Superconducting Coated Conductor Strip with Combined Transport Current and Magnetic Field

Vertically Polarized Broadband Gain Stable Yagi– Uda Antenna for Millimeter-Wave Applications

A millimeter-wave endfire Yagi–Uda antenna based on a monopole fed by a substrate-integrated waveguide (SIW) line is presented in this letter. The antenna consists of two substrates assembled perpendicularly in a 3-D configuration. The vertical plane supports the driven monopole antenna and a group of passive parasitic monopoles, all printed as conductor strips. The horizontal layer contains the SIW feeding line, where the top metallic face acts as a mirror for the monopoles. According to the beam direction and the achieved gain, a parametric study is conducted to determine the number of elements. Two versions are proposed, studied, and experimentally validated. The first version with one arm achieved a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-$</tex-math></inline-formula> 10 dB impedance bandwidth of 23.5% (27.4–34.7 GHz) with a peak gain of 13.8 dBi. The second version with three arms of directors is proposed to achieve a stable gain of 15.1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.5 dBi over 16% (27.1–32 GHz). The performance of the proposed antenna with relatively compact size makes it suitable for millimeter-wave systems.

Design of LTE/Sub-6 GHz Dual-Band Transparent Antenna Using Frame-Structured Metal Mesh Conductive Film

This paper proposes a dual-band transparent antenna using frame-structured metal mesh conductive film (MMCF). The frame-structured metal mesh conductive film is based on the conductive-coated thin film and forms a narrow strip surrounding the edge of the antenna. The frame-structured metal mesh conductive film can resist considerable current leakage on the edge of the conductive strip to improve the antenna's efficiency by 51% at 2.1 GHz and 53% at 3.6 GHz. As a result, the transparent dual-band antenna has an operating bandwidth of 1.9-2.4 GHz and 3.2-4.1 GHz with a high transparency of 80%, which make it valuable to the applications of biomedical electronic components, wearable devices, and automobile vehicles.

Enhancement of the Peak Power Handling Capability in Microstrip Filters by Employing Smooth-profiled Conductor Strips

Enhancement of the Peak Power Handling Capability in Microstrip Filters by Employing Smooth-profiled Conductor Strips