Characteristic Impedance Research Articles

A GCPW slow‐wave transmission line with improved wavelength reduction technique by adopting capacitor array

AbstractThis letter presents a grounded coplanar waveguide (GCPW) slow‐wave transmission line (SWTL) with an improved wavelength reduction technique by adopting capacitor array. By cross‐interleaving additional capacitors between a signal line and side ground planes, the total capacitance in the capacitor array increases approximately two times compared to the conventional structure, allowing designers to choose a smaller signal conductor's width for higher inductance, thus, improving wavelength reduction performance while preserving the same characteristic impedance. At the 150 GHz frequency of interest, the proposed GCPW SWTL shows approximately 20% and 62.16% reduction in wavelength compared to the reported GCPW SWTL and regular CPW, respectively, with the same characteristic impedance. To prove the effectiveness of the proposed SWTL concept, the proposed GCPW SWTL test patterns are fabricated in a 65 nm CMOS process.

Wide-angle non-reciprocal thermal radiator based on a periodic toroidal array structure

Non-reciprocal thermal radiation is crucial for energy transfer and storage applications. However, the range of angles of incidence limits the development of non-reciprocal thermal radiation. To address this problem, we have proposed and developed a non-reciprocal thermal radiation device with wide-angle characteristics, which operates in the mid-infrared spectral range. The radiator consists of a silicon-based periodic toroidal array, a Weyl semimetal (WSM), and a metal reflective layer Ag. A strong nonreciprocity of 0.88 is observed at 9.36 μm wavelength and 41.8° angle, while a nonreciprocity of 0.87 can be sustained within the range of 36°–74°. In addition, the nonreciprocity can be maintained above 0.8 in the spectral range of 9.3 μm ∼9.4 μm. Compared with the previous single working angle, our work has dramatically broadened the angle of energy absorption, and the non-reciprocal intensity can be maintained at a high level. Through a detailed analysis of the magnetic field modulus and impedance characteristics at non-reciprocal wavelengths, we reveal that cavity resonance excitation is the core physical process of mid-infrared wide-angle non-reciprocal radiation. In addition, changing the axial vector of the WSM can lead to a redshift of the non-reciprocal wave peaks. The proposed two-dimensional mid-infrared non-reciprocal emitter can realize wide-angle domain emission at specific wavelengths, which is promising for applications in energy storage and conversion systems such as solar cells and thermophotovoltaic cells.

Determination of phase components of impedance in the environments over hydrocarbon accumulation

Abstract The article presents a novel method for hydrocarbon accumulation exploration based on determining the phase components of impedance in environments over hydrocarbons. Experimental studies were conducted at the Rechitsa hydrocarbon field and Osipovichi underground gas storage. The phase characteristics of surface impedance of hydrocarbon accumulation were measured using amplitude-frequency-modulated signals. The results show that determining two components of surface impedance in this mode significantly improves the accuracy of hydrocarbon boundary determination. The developed method can be implemented at frequencies of 0.1-2 GHz, using modulation frequencies of 10-100 MHz, amplitude modulation coefficients of 0.1-1.0, and frequency modulation indices of 20-95. The findings of this research can be applied in electrical exploration for prospecting hydrocarbon accumulation.

A quasi-matching scheme for arbitrary group velocity match in electro-optic modulation

Group velocity and impedance matches are prerequisites for high-speed Mach–Zehnder electro-optic (EO) modulators. However, not all platforms can realize matching conditions, restricting high-speed modulation in many practical conditions. Here, we propose and demonstrate a quasi-matching scheme to satisfy the group velocity and characteristic impedance matches by cascading fast-wave and slow-wave traveling wave electrodes. The effective group velocity can be flexibly adjusted by changing the ratio of fast-wave and slow-wave traveling wave electrodes. Moreover, the quasi-matching scheme is experimentally verified by demonstrating a 6 mm long EO modulator on a thin-film lithium-niobate-on-insulator platform with a silica cladding. The radio frequency signal insertion loss at the boundary of the slow-wave and fast-wave electrodes is less than 0.12 dB. The measured small signal EO response of the quasi-matched EO modulator drops less than 2 dB at 67 GHz, while the measured small-signal EO responses of conventional slow and fast traveling wave EO modulators drop 4 dB at 67 GHz. The measured 100 Gb/s on–off key signal eye-diagrams of the quasi-matched EO modulator also exhibit an overwhelming advantage over conventional schemes. Therefore, our results will open many opportunities for high-speed EO modulators in various platforms.

Design and development of a cable impedance spectrum testing system based on dual-path IV

Design and development of a cable impedance spectrum testing system based on dual-path IV

Optimization of the deep extreme learning machine using the seagull algorithm for state of health prediction of lithium batteries

Abstract The ability to predict the State of Health (SOH) of lithium-ion batteries with precision is essential for guaranteeing their safe and consistent performance. Notwithstanding, measuring internal resistance and capacity accurately during live battery operation is an ongoing challenge. Existing SOH prediction models often fall short in terms of precision. To tackle this issue, a novel SOH estimation technique for lithium-ion batteries has been proposed. This technique uses electrochemical impedance spectroscopy and the Seagull Optimization Algorithm simultaneously with a Deep Extreme Learning Machine (SOA-DELM). The impedance characteristics of lithium-ion batteries are taken into account, with real and imaginary components and the modulus extracted as the health factor (HF). Then, the seagull algorithm ascertains the optimal structural parameter solutions for the DELM network. An estimation model is subsequently created by using the Seagull algorithm-optimized DELM, which aids in accurate SOH prediction for aging batteries. The proposed methodology is assessed by using an aged electrochemical impedance dataset, namely, 45 mAh commercial button batteries made with active materials composed of lithium cobaltate and graphite for positive and negative ends respectively. This openly accessible dataset is available in Nature Communications. Upon validation, the methodology proves to be highly precise.

Impedance Characteristics of Microfluidic Channels and Integrated Coplanar Parallel Electrodes as Design Parameters for Whole-Channel Analysis in Organ-on-Chip Micro-Systems.

Microfluidics have revolutionized cell culture by allowing for precise physical and chemical environmental control. Coupled with electrodes, microfluidic cell culture can be activated or have its changes sensed in real-time. We used our previously developed reliable and stable microfluidic device for cell growth and monitoring to design, fabricate, and characterize a whole-channel impedance-based sensor and used it to systematically assess the electrical and electrochemical influences of microfluidic channel boundaries coupled with varying electrode sizes, distances, coatings, and cell coverage. Our investigation includes both theoretical and experimental approaches to investigate how design parameters and insulating boundary conditions change impedance characteristics. We examined the system with various solutions using a frequency range of 0.5 Hz to 1 MHz and a modulation voltage of 50 mV. The results show that impedance is directly proportional to electrode distance and inversely proportional to electrode coating, area, and channel size. We also demonstrate that electrode spacing is a dominant factor contributing to impedance. In the end, we summarize all the relationships found and comment on the appropriateness of using this system to investigate barrier cells in blood vessel models and organ-on-a-chip devices. This fundamental study can help in the careful design of microfluidic culture constructs and models that require channel geometries and impedance-based biosensing.

Additional damping control for multi-terminal AC-DC hybrid system based on reachability analysis

Abstract The application proportion of multi-terminal AC-DC hybrid power distribution systems is constantly increasing. In order to describe the operation status and trajectory of the system and judge whether the system can maintain stable and safe operation, in this paper, the differential algebraic equation is firstly established by mathematical and physical methods for a typical multi-terminal AC-DC hybrid power distribution system. Then, the reachable set in the operation process is analyzed according to the reachability analysis calculation method to judge the stable operation status. An additional damping control method is proposed, which can effectively restrain the negative impedance characteristics of the DC micro-grid and improve the operation stability of the system. Finally, the improvement performance of the control method is verified by combining the reachability analysis results.

Impedance characterization of battery aging paths in energy storage operation mode

Impedance characterization of battery aging paths in energy storage operation mode

Corrosion study of glass coated high strength low alloy steel

In the present study, the glass slurry coating to a high-strength low-alloy steel (HSLA) substrate was investigated for corrosion resistance material. The crystallographic phases, degree of crystallinity, lattice parameters, and potential changes due to the coating process, and microstructural changes such as visual inspection of the surface, revealing thickness, uniformity, adhesion, potential defects, and elemental composition of the bare and coated steel were investigated by using the X-ray diffraction (XRD) and scanning electron microscopy and electron dispersive spectroscopy (SEM/EDS). The electrochemical behavior of the bare and coated steel samples was compared using potentiodynamic polarization and electrochemical impedance spectroscopy at various immersion periods in a 3.5 wt.% of sodium chloride (NaCl) solution. The higher corrosion resistance and lower corrosion rates of the coated steel surfaces were observed. The protection effectiveness of coatings is evaluated by examining their impedance and polarization characteristics. The effectiveness of the glass coatings in inhibiting corrosion is attributed to their role as a physical barrier and their ability to release corrosion inhibitors into the surrounding electrolyte. This information can be crucial for real-world applications requiring corrosion resistance.

Constructing crystalline/amorphous heterojunction in FeCo@C nanoboxes for enhanced electromagnetic wave absorption

The advanced electromagnetic applications urgently require high performance absorbers with sophisticated structural and compositional design. An effective strategy is to construct a three-dimensional hollow structure, with enhanced electromagnetic wave dissipation capacity over a wide effective absorption bandwidth. However, a major challenge remains due to a single loss mechanism system derived from the conventional hollow nanobox structure, which seriously causes impedance mismatch and lack of polarization centers. Herein, we innovatively construct novel hollow structure FeCo@C (CMFC) with crystalline/amorphous heterojunction FeCo/C particles by cation exchange method, thereby achieving enhanced electromagnetic wave absorption. The CMFC achieves Ku-band effective absorption with a reflection loss of −50.57 dB and effective absorption bandwidth of 5.35 GHz at 1.8 mm. The CMFC exhibits excellent microwave absorption performance due to the presence of crystalline/amorphous FeCo/C heterojunction, which is attributed to the balanced dielectric loss and optimized impedance matching characteristics. CST simulations demonstrate that the CMFC has a radar scattering interface reduction value as high as 26.12 dBm (Wu et al., 2023) [2] at a scattering angle of 0°. This work provides new ideas for the rational design of hollow nanostructures with heterojunction particles for efficient microwave absorption.

Beam-steerable filtering patch antenna with wide-stopband suppression and stable radiation characteristics

A method of designing beam-steerable patch antennas with wide stopband suppression is proposed in this article. The wide stopband suppression characteristic is realized by designing suitable parallel coupled lines and open-circuited stubs. The beam steering characteristic is achieved by using a driven patch and two pairs of metal walls vertically placed on both sides of the driven antenna. By controlling the different states of the switching PIN diodes loaded between metal walls, the stable beam steering characteristic can be obtained over the entire operating bandwidth. An experimental antenna is designed and manufactured to validate the approach. The beam steering angles of the simulation and measurement results are ±30°. Moreover, in the three proposed operating states, the out-of-band suppression from 2.6 GHz to 10 GHz is more than 16 dB. The proposed antenna can achieve the characteristic of both wide stopband suppression and beam steering. In addition, the proposed antenna is able to maintain good impedance characteristics during beam steering and maintain stable beam over the entire operating bandwidth.

Parameter Equivalence and Impedance Characteristics of NiTi Wires Embedded in Nitrile Butadiene Rubber Based on Secondary Bridging Model

This article presents a metal matrix composite material consisting of NiTi wires embedded in nitrile butadiene rubber (NBR) that preserves NBR’s inherent acoustic characteristics while enabling acoustic modification through the NiTi phase transition induced by stress and temperature. The macroscopic mechanical parameters of transversely isotropic NiTi-NBR composite materials are derived by means of a secondary bridging model that takes into account interfacial phases. On this basis, the acoustic impedance properties and absorption coefficient of composite materials were examined as a function of NiTi volume fraction using the transfer matrix method. The accuracy and effectiveness of the theoretical method were verified by comparing the calculated results with finite element simulation. The research results indicated that regulating the volume fraction of NiTi can lead to the anticipated value of the input impedance of composite materials, improving impedance matching with media like water and rubber, which offers novel insights and a theoretical foundation for the development of underwater sound-absorbing materials.

Failure mechanisms of the thyristor switch in pulsed arc electrohydraulic discharges

In order to study the failure mechanism of the thyristor switch in the application of electric pulse fracturing, an underwater pulse power discharge experimental platform was built, the impedance characteristics of the plasma channel were analyzed and the circuit equivalence was carried out for each discharge stage. Then, based on the Silvaco simulation software, a theoretical thyristor model was established. By observing the distribution of the internal carriers and current density, the turn-on and turn-off processes of the thyristor switch under high voltage were analyzed. The formation factors of peak voltage in the turn-off process were studied, the easy breakdown position was pointed out, and a method to suppress the reverse peak voltage by creating critical damping oscillations in the discharge circuit was proposed. Finally, a pulsed power discharge experiment was carried out to verify the theoretical analysis. The experimental results show that the discharge waveform conforms to the theoretical analysis, and the high voltage breakdown damage of the thyristor is also consistent with the theoretical simulation model. Furthermore, the proposed thyristor protection method can greatly suppress the reverse voltage spike, reduce the peak voltage by 52%, and effectively avoid the damage caused by withstand voltage breakdown in the application of pulse power discharge.

Data Communication Over Power-lines: A Review on Technical, and Applications Challenges

This paper presents a review study on the data communication over power-lines, commonly referred to as power-line carrier, power-line communication (PLC), mains communications, or power-line digital subscriber line (PDSL). This study examines the technical and application advantages and challenges associated with adopting PLC as a preferred alternative technology for wideband or broadband data communication. The broader coverage area of the PLC network gives it a distinct advantage over other communication network technologies. Additionally, implementing a communication system using the existing power-line network is more cost-effective and less time-consuming compared to constructing a new network from scratch. However, the primary challenge lies in the fact that the power-line network is primarily designed for the distribution of electrical power within the frequency range of 50-60 Hz including the harmonics. This poses various obstacles such as electrical noise from appliances, signal distortions caused by the unregulated nature of the wiring, transformer bypassing, interference from high-frequency modulation, and variations in characteristic impedances, among others. Despite these challenges, the emergence of robust modulation techniques like Orthogonal Frequency Division Multiplexing (OFDM) and Direct-Sequence Spread Spectrum (DSSS), along with the development of Application-Specific Integrated Circuit (ASIC) density with improved processing speeds, as well as advancements in signal processing and error control coding techniques, have made the PLC network the most promising telecommunications access network.

Application of Cellulose and Paper-Based Products in Building Acoustics

This article presents a comprehensive acoustic study of paper-based building products: cellulose wool, paperboard, corrugated cardboard, and honeycomb panels. The material configurations included the intact form as well as the various modifications, i.e., density variation, multiple-layered staking, perforation or acoustic metamaterial setup. Tests covered acoustic absorption and insulation properties, with the last examined under excitation of both a plane wave and a diffused field. Additionally, the cellulose wool is provided with the characteristic impedance and propagation wavenumber results; and the paperboard was tested for its dynamic elastic and damping properties. The paper-based products, giving their weight, prove to be a convincing replacement for conventional materials by both absorptive and insulation performance. The maximum acquired sound reduction index, for exceptionally lightweight (2.2 kg/m2) paper double-wall metamaterial structure, reached 26 dB.

Development of a Prototype Hydraulic Damping Device for Hot Water Heating Circuit in Pulse Mode

This paper provides a comprehensive exploration into the design and implementation of the hydraulic damping device within a pulse mode hot water heating loop. It outlines a systematic approach aimed at optimizing system performance, detailing the operational principles of the pulse mode heating circuit and presenting a structured construction scheme for the hydraulic damping apparatus. Accompanying this analysis is a simplified diagram illustrating the hydraulic damping system, offering a clear visual representation of its integration within the heating circuit. Through mathematical transformations, essential parameters such as complex impedance, frequency function, and vibration frequency characteristics are derived, providing valuable insights into the dynamic behavior of the system. Culminating this investigation, the paper constructs the frequency response of the circuit, offering a comprehensive understanding of its dynamic behavior across varying frequencies. This synthesis of theoretical frameworks and practical applications advances our understanding of pulse mode hot water heating technology, paving the way for enhanced efficiency and performance in heating systems.

Electric and dielectric responses of Au/n-Si structure by Mn doped PVC interfacial layers

This paper has investigated and compared the impact of polyvinyl chloride (PVC) without/with manganese (Mn) metallic nanoparticles interfacial layer on the electric and impedance characteristics of Schottky diode (SD) with a structure of Au/n-Si (MS). The structures of these two metal-polymer-semiconductor (MPS) SDs are Au/PVC/n-Si and Au/PVC:Mn/n-Si. A detailed description of the SDs manufacturing process is given. The x-ray diffraction (XRD) analysis, Scanning Electron Microscope (FE-SEM) images, and Electron Dispersive x-ray (EDX) spectroscopy are three methods that have been utilized to examine mean size of crystallite, morphology of surface, purity specification. The fundamental electronic variables of these devices are ascertained and contrasted with one another using the I-V characteristic measurement at ±6 V. Ohm’s law, Thermionic Emission (TE) theory, modified Norde, and Cheung functions are used to calculate the SDs’ leakage current (I0), ideality coefficient (n), potential barrier height (BH), shunt (Rsh), and series (Rs) resistances. Investigations are conducted on the energy dependence of surface states density (Nss) and the current conduction mechanisms (CCMs) for both reverse and forward biases. These interfacial layers are known to decrease the n, Rs, and Nss. The PVC polymer interlayer leads to improve the efficiency of the MS-type SD, but it does not when doped by Mn nanoparticles. Additionally, by measuring impedance at a bias of 1.5 V and 100 Hz-1 MHz frequency range, the frequency dependence of dielectric properties of the prepared SDs is studied. The dielectric permittivity, dielectric loss tangent, electronic modulus, and ac electronic conductivity of these SDs are all studied.

The two-cavity method for characterizing acoustical materials-an interlaboratory study

The study focuses on understanding the sound absorption and transmission characteristics of porous acoustical materials, which are determined by two key parameters independent of material thickness: characteristic impedance and propagation constant. These parameters can be characterized by testing a porous sample concept in a normal incidence impedance tube using either the two-thickness or the two-cavity method. In the two-thickness method, two samples of varying thicknesses are required. In contrast, the two-cavity method requires testing one sample at two air cavity depths. This method is particularly advantageous for materials that are costly or challenging to fabricate. This interlaboratory study evaluates the variability of characteristic properties determined using the two-cavity method. Porous acoustical materials were additively manufactured and tested in the Liner Technology Facility at NASA Langley Research Center and the Mechanics, Acoustics and Dynamics Lab (MADLab) at Michigan Technological University. The characteristic properties, derived from various cavity depth combinations, were used to predict the sound absorption curves of the sample with a rigid backing. These predictions were then compared with actual experimental absorption curves. The findings indicate that both the combinations of cavity depths and the sample's static airflow resistivity significantly influence the accuracy of the deduced properties.

Exploring the structural characteristics and electrical conductivity of MnTiO3 across ferroelectric and paraelectric phases

In this study, we present the ceramic's structural, dielectric, and impedance characteristics obtained through the solid-state reaction method synthesis. Initial structural analysis was conducted utilizing X-ray diffraction at room temperature. The XRD results show that MnTiO3 exhibits rhombohedral symmetry. SEM images of MnTiO3 show the presence of both cubic and large agglomerated grains. This demonstrates the effectiveness of the dielectric HN model in controlling the mechanism. The alternating current (ac) conductivity, when examined in relation to frequency, displays a remarkable adherence to the Johnscher's power law. The change in electrical modulus and the width at half maximum (FWHM) of the curve indicate that the as-prepared sample exhibits a non-Debye relaxation mechanism. Both the temperature data and the frequency dependence of the impedance were used to analyze the electrical conductivity of the sample, which showed a negative temperature coefficient resistance (NTCR).