Parallel Coplanar Research Articles

Effects of Bolt Anchoring on Shear Mechanical Performance and Acoustic Emission Characteristics in Two Parallel Coplanar Rock-Like Materials

Effects of Bolt Anchoring on Shear Mechanical Performance and Acoustic Emission Characteristics in Two Parallel Coplanar Rock-Like Materials

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.

Spatially resolved capacitance-based stress self-sensing in concrete

Spatially resolved capacitance-based stress self-sensing in unmodified concrete has been demonstrated. The spatial resolution is 45 mm in one dimension, which is in the direction of the capacitance measurement. Parallel coplanar component electrodes (aluminum, 5-mm wide), attached to the concrete using double-sided adhesive tape) separated by 45 mm are used to measure the in-plane capacitance in the direction perpendicular to the length of the electrodes. Combinations of component electrodes are electrically connected to form an electrode. The capacitance ranges from ∼200 pF to ∼750 pF. The greater is the number of component electrodes in an electrode, the higher is the capacitance. The compressive loading is applied at selected areas located between adjacent component electrodes. The stress (defined as load divided by the 300 ×300-mm2 concrete area) is up to 3000 Pa. The load decreases the capacitance monotonically and reversibly. The fractional decrease in capacitance ranges from ∼0.1 % to ∼0.5 %. More spatially concentrated loading, as for loading near the edges of the specimen, gives greater fractional decrease in capacitance. The capacitance decreases with increasing inter-electrode distance. Embedded steel rebars with a 20.0-mm concrete cover do not affect the capacitance or capacitance-based sensing.

ЄМНІСНИЙ СЕНСОР З СИСТЕМОЮ ПАРАЛЕЛЬНИХ КОМПЛАНАРНИХ ЕЛЕКТРОДІВ ДЛЯ ВИМІРЮВАННЯ ПОВІТРЯНОГО ЗАЗОРУ В ГІДРОГЕНЕРАТОРАХ

A capacitive sensor for measuring the air gap between the boring of the stator core and the poles of the rotor in a powerful hydrogenerator is proposed and investigated. The sensor consists of a system of equal in width tape parallel coplanar high-potential and low-potential electrodes, between which grounded electrodes are placed. The ratios between the width of the high-potential, low-potential and grounded electrodes are selected depending on the size of the nominal gap. The electrodes are formed on a dielectric substrate mounted on the boring of the stator core. To reduce the effect of edge effects on the short sides of high-potential electrodes, the length of the low-potential electrodes is chosen to be smaller than the length of the high-potential electrodes by a value determined by the nominal gap. It is proposed to place all electrodes along the length perpendicular to the boring core generatrix to reduce the measurement error due to the influence of the rotor pole curvature. The electrical capacitance between the system of high-potential electrodes connected in parallel and the system of low-potential electrodes connected in parallel, which functionally depends on the size of the air gap, is measured. Analytical and graphical dependences for the sensor conversion function intended for use on a SGK538 / 160-70M bulb hydrogenerator have been determined. The value of the error caused by the curvature of the rotor poles in this hydrogen generator was calculated. The sensor in comparison with analogs has higher accuracy of measurement. The sensor or sensor system can be used as a stand-alone device or as part of monitoring and diagnostic systems. References 19, figures 6.

Tunable dual‐spectral plasmon‐induced transparency in terahertz Dirac semimetal metamaterials

AbstractWe have numerically studied a tunable dual‐spectral plasmon‐induced transparency metamaterial structure based on Dirac semimetal films in the terahertz region. The structure was composed of three length‐variant parallel coplanar strips. The dual‐spectral plasmon‐induced transparency is mainly induced by the bright‐bright modes coupling between neighboring Dirac semimetal strips. By adjusting the Fermi energies of Dirac semimetal strips, the individual and synchronous modulation of the dual‐transparency window in resonance frequency, bandwidth and strength can be obtained, respectively. Simultaneous change of the Fermi energies of all the strips can achieve an overall frequency shift of the dual‐transparency window, with the frequency modulation depth of 21.7% and 20.0%, respectively. The maximum group delays of 5.26 and 3.57 ps for each window were calculated in our proposed structure. The simulation results demonstrated the potential of the proposed structure to expand the applications for slow‐light systems, filters, and switchers in the terahertz region.

Effects of Joint Roughness, Shear Rate, and Normal Stress on Shear Behavior and Acoustic Emission Characteristics in Two Parallel Coplanar Intermittently Jointed Rock: An Experimental Study

Effects of Joint Roughness, Shear Rate, and Normal Stress on Shear Behavior and Acoustic Emission Characteristics in Two Parallel Coplanar Intermittently Jointed Rock: An Experimental Study

Mutual inductive magnetic sensor consisting of a pair of coplanar parallel winding spiral coils sandwiched by soft magnetic ribbons

The paper proposed a mutual inductive magnetic sensor composed of a pair of parallel winding spiral coplanar coils sandwiched by soft magnetic ribbons. Because the layout of coils is in a single individual layer, the gap between the magnetic ribbons up and down is decreased compared with the previous multilayer laminated magnetic sensor. Therefore, the magnetic leakage is ameliorated, and the electromagnetic coupling between the coils and ribbons is strengthened, which in turn enhances the sensitivity. The magnetic sensor can provide a sensitivity of 5.73 mV/Oe at an excitation frequency of 500 kHz, exhibiting an enhancement of 5 times relative to the multilayer laminated sensor. In addition, the resolution of the magnetic sensor is 0.18 nT. More importantly, the structure is particularly suitable for micromachining, providing the possibility for manufacturing high-performance micro-magnetic sensors with simpler planar technology.

Dual-Loop Arrays Fed by Coplanar Parallel Lines for Wideband Circular Polarization

Using the method of moments, we analyze three types of series-fed array antennas for circular polarization. First, we present a reference antenna's radiation characteristics with symmetrical dual loops fed by balanced parallel lines. Next, we modify the symmetrical dual loops into asymmetrical ones to enhance a circularly polarized (CP) wave bandwidth. It is found that the modified antenna has a bandwidth of 35% for a 3 dB gain-drop criterion, where the axial ratio is less than 3 dB. Finally, we use unbalanced parallel lines for feeding the asymmetrical dual loops to simplify the feed system. It is revealed that the antenna shows a CP wave bandwidth of 19%, which is twice as wide as that of the reference antenna.

Measuring Transducer for Air Gap Capacitive Sensor in Hydrogenerator

One of the most important parameters of powerful hydro generators (HG) is the air gap between the rotor and the stator, and its deviation from the set norms is a defect that can lead to serious accidents. Therefore, the size and shape of the gap must be monitored both during inspections and during operation of the machine. The aim of this paper was to develop a secondary measuring transducer providing accuracy and resolution for a capacitive gap sensor formed by coplanar parallel electrodes. It is shown that the reliability and safety of operation of powerful HG inextricably depend on the timely detection of their defects, especially during operation. One of the most important parameters of the HG is the air gap between the rotor and the stator, and its deviation from the set norms is a defect that can lead to serious accidents. Therefore, the size and shape of the gap must be monitored both: during inspections and during operation of the machine. The paper discusses the features of measuring the air gap in a powerful HG, as well as existing modern methods and means of measurement. It is shown that for measuring the gap in capsule HG, one of the most suitable means is a meter, which includes a capacitive sensor mounted on a central bore of the stator core. Commercially available gap meters with capacitive sensors are not suitable for use on HGs. Commercially available meters with capacitive sensors, by their certain characteristics, are not always suitable for use on HGs. A secondary measuring transducer with improved characteristics is proposed for a capacitive gap sensor formed by coplanar parallel electrodes. The converter is developed on the basis of a balanced compensation bridge measuring circuit. The control action in the device is formed by the phase of the unbalancing signal. The structural diagram of the converter is presented and the algorithm of its operation is described. The process of forming a measuring output signal proportional to the sensor working capacitance in the circuit is considered. The use of a capacitive sensor with coplanar parallel electrodes and the proposed secondary measuring transducer will ensure high accuracy and resolution when measuring the air gap.

Crystal structures of (E)-5-(4-methyl-phen-yl)-1-(pyridin-2-yl)pent-2-en-4-yn-1-one and [3,4-bis(phenyl-ethyn-yl)cyclo-butane-1,2-di-yl]bis-(pyridin-2-yl-methanone).

Recrystallization of (E)-5-phenyl-1-(pyridin-2-yl)pent-2-en-4-yn-1-one at room temperature from ethyl-ene glycol in daylight afforded [3,4-bis-(phenyl-ethyn-yl)cyclo-butane-1,2-di-yl)bis-(pyridin-2-yl-methanone], C32H22N2O2 (3), while (E)-5-(4-methyl-phen-yl)-1-(pyridin-2-yl)pent-2-en-4-yn-1-one, C17H13NO (2), remained photoinert. This is the first experimental evidence that pentenynones can be photoreactive when fixed in nearly coplanar parallel positions. During the photoreaction, the bond lengths and angles along the pentenyne chain changed significantly, while the disposition of the pyridyl ring towards the keto group was almost unchanged. The cyclo-butane ring adopts an rctt conformation.

Frequency-Selective Rasorber With a Wide High-Transmission Passband Based on Multiple Coplanar Parallel Resonances

A dual-polarized frequency-selective rasorber (FSR) with a wide high-transmission passband and two absorption bands is proposed and investigated in this letter. The proposed FSR, is composed of a lossy and a lossless layer, is formed by introducing a broadband transmission window into a wider absorption band. Simple guidelines based on an impedance analysis are proposed, and the wide high-transmission passband is realized by connecting multiple coplanar parallel resonances (MCPRs) in a series, which introduces a large impedance in a wide band for the lossy layer. In this design, the lossy layer and lossless layer consist of a square ring absorber with multiple interdigital resonators and a multilayer broadband frequency selective surface, respectively. The simulation results indicate that the 1 dB transmission window can be obtained from 8.12 to 11 GHz with a 30.4% fractional bandwidth, and the bandwidth of reflection below –10 dB is up to 111% from 4 to 14 GHz. Finally, the proposed structure is fabricated and measured. Both the simulation and experimental results agree well, which suggests that the concept of connecting MCPRs in series can generate a broadband transmission window effectively.

Circular Polarization Diversity Implementation for Correlation Reduction in Wideband Low-Cost Multiple-Input-Multiple-Output Antenna

In this paper, a multiple-input-multiple-output (MIMO) antenna featuring circular polarization diversity, and designed on a common coplanar ground is presented. The proposed antenna design utilizes a coplanar waveguide (CPW) feeding technique with three parallel coplanar ground planes, and two feedlines in-between. For circular polarization (CP), quasi-loops are created by etching slots on the outermost ground planes. With this configuration, circular polarization diversity is induced in the MIMO antenna with the left-hand CP (LHCP) from one antenna and the right-hand CP (RHCP) from the other. The total footprint of the antenna radiator is only 0.78λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.55λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> = 0.42λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Experimental results show perfectly overlapping impedance and axial ratio bandwidths of 39.3% (4.5 GHz to 6.7 GHz). In addition, average in-band isolation |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> | ≤ -15 dB without any added complexity or active circuit elements. The peak realized gain of the antenna is 5.8 dBic with broadside radiation pattern in the +zdirection and envelope correlation coefficient (ECC) of 0.005. The antenna is suitable for multiple applications in the C-band that includes WLAN (5 GHz, 5.2 GHz and 5.8 GHz) and WiMAX (5.5 GHz).

Enhancement of transmission characteristics for the antenna system printed on silicon wafer substrate by using FSS‐based coplanar parallel reflector

Here, a silicon-substrate-based four element antenna system is investigated by using a coplanar frequency selective surface (FSS) as a novel parallel reflector to improve radiation and transmission characteristics of the antennas. The four antennas are arranged around the square FSS, and one of the antennas is used as the transmitting element, while the other three as the receiving ones. It is found that, owing to the stopband filtering and the linearly changing reflection phase of the designed coplanar FSS, the gain and directivity of the transmitting antenna have been greatly improved, and that the antenna system transmission coefficients, including S 21, S 31 and S 41, have been significantly increased. Two types of the antenna systems have been designed and fabricated on a P-type silicon wafer substrate for the cases with and without a coplanar FSS reflector. The measured S-parameters are essentially consistent with those simulated. In comparison with the case without the FSS, the transmission coefficients of S 21, S 31 and S 41 for the system with the FSS have been increased about 6.42, 5.97 and 5.89 dB at the center frequency of 5.42 GHz, respectively. Furthermore, the proposed coplanar FSS exhibits distinct advantage of low-profile compared to the conventional vertical FSS reflector.

Vital Sign Monitoring Using Capacitive Sensing.

Unobtrusive vital sign monitoring is essential for most wearable monitoring applications. This paper presents a new method for unobtrusive vital sign monitoring based on the change in capacitance of passive sensors in contact with the user's body. Unlike traditional capacitive coupling that is commonly used for elimination of the DC component of bioamplifiers, we propose monitoring of heart rate using galvanically isolated capacitive sensors. This paper presents the theory of operation and the implementation of a prototype device for heart rate monitoring. A prototype capacitive sensor was implemented using parallel coplanar plates in contact with the tip of the finger. Preliminary testing allowed us to observe changes in capacitance in the range of 0.1-0.3 pF per heartbeat, or 0.3-0.9% of the measured signal. The detected heart rate was validated using a PPG sensor positioned on the same hand. During a single recording session of 772 s, the detected heart rate was within 3 BPM 42% of the time. Proposed method is sensitive to motion artefacts; however, processing of signals collected from multiple contact points may facilitate removal of motion artifacts. Since many microcontrollers directly support high quality monitoring of capacitance on multiple I/O pins, the proposed method provides a promising solution for a low-power, low-cost, multi-contact monitoring.

Analysis, Modeling, and Mitigation of Parasitic Resonances in Integrated Metallic Seal Rings

The cause of a measured −1.4-dB dip at 80 GHz in a silicon capacitor was investigated and determined to be the primary resonance of the integrated metal seal ring (SR) enclosing the component. Specifically, the proximity of a capacitor electrode to the SR was found to activate two parasitic, parallel, and open-circuited coplanar strip transmission lines (TLs), each having their ${\lambda /2}$ resonance at this frequency. This model was confirmed with 3-D finite-element method electromagnetic simulations and measurements of modified SRs. Building on the proposed TL interpretation of the problem, an ultra-broadband equivalent circuit model was developed for such capacitors, successfully replicating the measured SR resonance. Then, the fundamental resonance frequency and related quality factor of various-sized integrated metal SRs were accurately predicted. Finally, potential solutions to damp or cancel such parasitic resonances were investigated. Although cutting the SR at selected locations to disable the parasitic lines was experimentally proven to be successful, damping the parasitic signal with highly doped silicon is found to be the best option in terms of effectiveness and practical implementation. Novel solutions, analogous to the use of radio frequency terminations, were also tested. This paper, to the best of our knowledge, is the first extensive characterization of parasitic resonance afflicting electronics enclosed by an integrated metal SR. The analysis, equivalent circuit model, and solutions reported here can be directly applied to arrays of components or circuits, and are scalable to any device size and operating frequency.

AIR GAP CONTROL SYSTEM FOR HYDROGENERATORS

In this paper, we report of the solving the actual problem of control the air gap in the hydrogenerators. The aim of the study was development of a computerized information-measuring system for measuring the air gap in the hydrogenator, which used two capacitive sensors with parallel coplanar electrodes, and the method of determining the shape of the envelope parameters hydrogenerator rotor poles relative to the center axis of rotation, using the measurement results of the air gap.In practical studies of the sensor circuit it has been shown that its use allows for the informative value of the sensor capacitance conversion function to obtain a high accuracy and resolution measurement with digital linearization of converting function of the sensor with use program utility. To determine the form deviations of the envelope line of the rotor pole from the ideal cylinder, which is one of the main structural defects of the technological errors as results the distortion of the shape of the air gap in the hydrogenator, when the machine was manufacture and assembly. It is proposed to describe the shape of the envelope to use a Fourier transform. Calculation of the coefficients of the Fourier series is performed using the method of least squares as the regression coefficients.Application of this method in processing the measuring data in a computerized information-measuring system the developed with the primary converter with coplanar parallel electrodes allowed attaining the high measurement accuracy and resolution informative in magnitude of the capacity.

Dual‐polarisation reflectarray made of cells with two orthogonal sets of parallel dipoles for bandwidth and cross‐polarisation improvement

A reflectarray antenna has been proposed to provide broadband operation, low cross-polarisation and independent beamforming in dual linear polarisation. The reflectarray element consists of two orthogonal sets of three coplanar parallel dipoles, where each set of parallel dipoles is used for controlling the phase-shift of each polarisation. A focused beam 40 cm reflectarray has been designed, manufactured and tested. According to the experimental results, the antenna shows a 27% bandwidth for a gain of 32.9 dBi with a variation of 1 dB. The antenna efficiency is better than 60% and the maximum cross-polar radiation levels are at least 30 dB below the main beam co-polar levels for both linear polarisations. In addition, it has been demonstrated that the antenna performance is maintained when it is designed to provide two separate beams in each linear polarisation.

Investigations on Modeling and Simulation of Printed Folded Dipole Antenna

We have modeled and simulate asymmetric microstrip folded dipole antenna on substrate materials and study the antenna performances. The conventional wire dipole antenna configurations are converted into corresponding microstrip version. The complementary nature of parallel coplanar strip line and waveguide models have been used to model the dipole antenna. The transmission line parameters namely, even-odd mode effective dielectric constant and characteristic impedance have been analyzed. We study the effect of dielectric material on radiation characteristics of the printed folded dipole antenna, such as effective dielectric constant, characteristics impedance, input impedance and bandwidth. The antenna shows bandwidth improvement below 3 GHz frequency with asymmetric form of strip folded dipole.

Broadband reflectarrays made of cells with three coplanar parallel dipoles

ABSTRACTA broadband reflectarray cell made of three parallel dipoles printed on a dielectric layer is presented. A 33% bandwidth is achieved for the cell made of dipoles, which is larger than that obtained for a reference cell consisting of three stacked square patches (26%). Using this cell, a 41‐cm reflectarray antenna has been designed to produce a collimated beam at 9.5 GHz. The numerical results obtained for the reflectarray antenna made of parallel dipoles show a 1‐dB bandwidth of 19%, a 65% efficiency, 0.2 dB of losses, and low levels of cross polarization (25 dB below the maximum). These results demonstrate a high performance for the proposed reflectarray antenna made of cells with three printed dipoles. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:748–753, 2014

Efficient numerical tool for the analysis and design of reflectarrays based on cells with three parallel dipoles

AbstractIn this article, the Method of Moments in the spectral domain (MoM‐SD) is applied to the analysis of multilayered periodic structures, containing three coplanar parallel dipoles in the unit cell. It is shown that the use of basis functions with edge singularities in the modeling of the current density on the dipoles leads to important computer memory and CPU times savings in the analysis of the periodic structures. The MoM‐SD home‐made software is used in the analysis of a shaped beam reflectarray antenna made of cells with three parallel dipoles under the local periodicity assumption. The numerical results obtained for the radiation pattern of the antenna are compared with numerical results provided by the commercial software CST® and with measurements and good agreement is found. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1212–1216, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27533