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Journal articles on the topic 'Resonant inductive-capacitive (L-C) circuit'
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1
Gizatullin, Farit A., Zulfiya G. Gabidullina, and Andrey V. Lobanov. "RESONANCE PHENOMENA IN AIRCRAFT ENGINE IGNITION SYSTEMS." ELECTRICAL AND DATA PROCESSING FACILITIES AND SYSTEMS 19, no. 2 (2023): 7–15. http://dx.doi.org/10.17122/1999-5458-2023-19-2-7-15.
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The relevance An analysis of scientific and technical literature in the field of development and research of aircraft engine ignition systems shows that the manifestations of resonant processes in nonlinear discharge circuits of capacitive ignition systems in the presence of two energy storage devices - a storage capacitor and an inductor coil have not been studied with the issuance of recommendations for matching the parameters of energy storage devices. This problem is of significant practical interest from the point of view of optimizing the parameters of the discharge circuits, increasing the energy efficiency and igniting ability of ignition systems. Aim of research Revealing the possibilities of increasing the efficiency of capacitive ignition systems based on the use of the manifestation of resonant processes in nonlinear discharge circuits containing two energy storage devices. Research methods Studies have been carried out involving a theoretical description of the processes during the discharge of the former charged capacitor to the R-L circuit, followed by experimental confirmation of the assumptions of the alleged states, described with the alleged resonance of occurrence in the discharge circuit using a similar falling current-voltage characteristic. Results The manifestations of resonant phenomena in a capacitive ignition system during the discharge of a capacitor on a non-linear circuit R-L are investigated. It is theoretically substantiated and experimentally proved that the dependences of the voltage in the spark discharge, the current and the energy of the discharges on the capacitance of the storage capacitor at a fixed inductance of the discharge circuit are uneven with inflection points corresponding to the equality of the inductive and capacitive resistances. It is shown that the energy efficiency of the discharge circuit can remain practically unchanged with a more than 1.5-fold decrease in the capacitance of the storage capacitor in the region of manifestation of resonant processes. The results obtained make it possible to coordinate the parameters of capacitive ignition systems, to determine the optimal values of the inductance of the discharge circuits for a given value of the capacitance of storage capacitors to ensure maximum energy efficiency and igniting capacity.
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Radovanovic, Milan, Sanja Kojic, Dragana Vasiljevic, and Goran Stojanovic. "Characterization of LC sensor structures realized by PCB and LTCC technology for determining moisture in building materials." Processing and Application of Ceramics 12, no. 1 (2018): 13–20. http://dx.doi.org/10.2298/pac1801013r.
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This paper compares performances of two wireless sensors for measuring water concentration in building materials, one manufactured by the printed circuit board (PCB) technology and another one using the low temperature co-fired ceramics (LTCC) process. The fabricated sensors consist of inductive part (L) and interdigitated capacitive part (C) in one metal layer, connected in parallel. Inductance of inductive part was kept constant, whereas capacitance of capacitive part was changed by exposing the sensor to different moisture concentration, changing its resonant frequency. The variation of resonant frequency as a function of different water concentration was measured, using antenna coil and impedance analyser, in two widely used construction materials: clay brick and autoclaved aerated concrete block. Surface analysis for two sensors was performed by means of 3D profilometer. Mechanical properties of the sensors were measured for both conductive segments (copper and silver) and substrates materials (PCB and ceramics substrates) using nanoindenter. Comparative characteristics of the sensors are presented from their application point of view.
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Hadiningrum, Kunlestiowati, Ratu Fenny Muldiani, and Defrianto Pratama. "The Effect of Capacitance on the Power Factor Value of Parallel RLC Circuits." Current Journal: International Journal Applied Technology Research 1, no. 2 (2020): 120–27. http://dx.doi.org/10.35313/ijatr.v1i2.27.
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The power factor of the circuit is determined by the amount of pure resistance (R), self-inductance of the coil (L) and the capacitance of the capacitor (C). In this study, the measurement of the power factor value in a parallel RLC circuit was carried out through experimental testing and simulation with the value of C as the independent variable, while the values of R and L were fixed conditioned quantities. The purpose of this study was to determine the effect of capacitance on a parallel RLC circuit. One of the ways to improve the power factor value in a circuit is to install capacitive compensation using a capacitor. The relation between the power factor value and the capacitance and inductive reactance based on the experimental results and the simulation calculation results in the parallel RLC circuit both shows the same pattern with a relative uncertainty below 8%. The experimental results and simulation results both show that the power factor can be improved by using a right capacitance which is around the capacitance value when there is resonance in the circuit.
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Nirala, Gurudeo, and Shail Upadhyay. "Study of phase evolution and dielectric properties of Sr2Mn0.7Sn0.3O4." Processing and Application of Ceramics 17, no. 2 (2023): 181–88. http://dx.doi.org/10.2298/pac2302181n.
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Ruddlesden-Popper oxide Sr2Mn0.7Sn0.3O4 was synthesized by solid state method by calcining at different temperatures between 1200 and 1500?C. The phase evolution during thermal treatments was investigated and it was shown that the powder calcined at 1500?C and ceramics sintered at 1500?C have single phase structure. Rietveld refinement of the XRD data confirmed tetragonal crystal structure having a = b = 3.9425 ? and c = 12.1230? lattice parameters and I4/mmm space group symmetry. Permittivity (?), impedance (Z*), dissipation factor (tan ?) and AC conductivity (?AC) of the samples were studied in the frequency range 1 kHz-2MHz and temperature range 60-600?C. An equivalent circuit comprising two parallel R-L elements and one constant phase element (CPE) model fitted the impedance data very well. Components of the equivalent circuit were correlated with compositional micro inhomogeneities in the sintered sample. Resonance-like feature observed in the dissipation factor at a particular temperature is attributed to the cancellation of capacitive and inductive reactants. Negative permittivity and loss of the sintered sample were compared with other ceramic oxides showing negative permittivity.
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Zheng, Xiao Hu, and Chang Yong Han. "A Micro Pressure Sensor Based on SU-8 Polymer." Applied Mechanics and Materials 220-223 (November 2012): 1902–5. http://dx.doi.org/10.4028/www.scientific.net/amm.220-223.1902.
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This paper investigated an novel wireless RF pressure sensor fabricated with SU-8 polymer. The sensor consists of an inductor (L) interconnected with pressure-variable capacitor (C) to form a LC resonant circuit. The fabricated devices is 4 × 3 mm2 in size and houses 9 turns of Cu electro-plated coil with inductance of 100 nH. In this system, RF signal was transmitted from external antenna to the fabricated LC resonator. Then RF signal was changed as power of fabricated device via inductive coupling. The external antenna was modulated by resonant frequency of the LC resonator. By detecting this abrupt resonant frequency shift of the device, the pressure change of the device can be measured by wireless method.
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Janardhanan, Shankaran, Joan Z. Delalic, Jeffrey Catchmark, and Dharanipal Saini. "Development of Biocompatible MEMS Wireless Capacitive Pressure Sensor." Journal of Microelectronics and Electronic Packaging 2, no. 4 (2005): 287–96. http://dx.doi.org/10.4071/1551-4897-2.4.287.
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The objective of this research was to develop a wireless pressure sensor useful for monitoring bladder pressure. The wireless sensor consists of an active capacitive element and an inductor coil. The changes in pressure are related to the changes in the resonant frequency of the internal sensor. The existing pressure sensors have inductors formed on both sides of the substrate. The changes in internal capacitance of these sensors are related to the changes in pressure by impedance matching of the internal LC circuit. The deviation in bladder pressure is an important variable in evaluating the diseased state of the bladder. The inductor designed for this application is a spirally wound inductor fabricated adjacent to the capacitor. The external sensing uses equivalent changes in internal LC. The resonant frequency of the internal sensor is defined by the deformation of the plate, causing the plate to touch the dielectric on the fixed capacitive plate, which is reflected as changes in capacitance(C). The deformation of the plate has been modeled using Finite Element Analysis. The finite element analysis optimizes the dimensions of the design. Remote sensing is achieved through inductive coupling and the changes in pressure are determined. The device is tested for pressures ranging from 0–150 mmHg, bladder pressure. The RF Telemetry system has been modeled using Sonnet. The frequency range is between 100–670 MHz which is in compliance to that specified by Federal Communications Commission (FCC) regulations.
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Galli, Valeria, Tyler J. Cuthbert, Chakaveh Ahmadizadeh, and Carlo Menon. "Preliminary investigation of the effect of artificial sweat on a wearable textile sensing system." Current Issues in Sport Science (CISS) 9, no. 2 (2024): 086. http://dx.doi.org/10.36950/2024.2ciss086.
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Introduction Textile wearable systems for human movement monitoring are increasingly popular. However, few examples report on robustness to sweat, which is relevant for use in real life. Some reported the effect of artificial sweat like phosphate buffered saline (PBS; Lin et al., 2022) or simply moisture (Xu et al., 2020) on custom materials. We previously developed an all-textile wireless sensing platform with commercial conductive yarns and fabrics containing silver. There is no study on the effect of sweat on such materials, therefore we performed a preliminary study to account for moisture and potential oxydation of silver. Methods The textile sensing system is resonating RLC circuit, where the sensing part is a capacitive parallel plate strain sensor (C) located on a joint (knee). All components are textile based and contain silver. As the capacitive sensor stretches, capacitance increases and the resonance of the circuit fres decreases. This information is transmitted wirelessly via inductive coupling (Galli et al., 2023). We sprayed 1 ml of 0.1 M PBS solution on the textile capacitive sensor to simulate sweating, and applied mechanical strain before (damp state) and after air drying (dry state). The unmodified sensor (before the addition of any PBS) was also used as a baseline measure. First, we applied fixed strain (10%) with a universal testing machine; then, we tested the response of the sensorized pants when bending the knee. Results The resonance frequency of the textile sensing (RLC) circuit in the damp state was much lower than the baseline (14.85 ± 0.11 MHz vs 22.70 ± 0.12 MHz) as expected from the higher dielectric constant of water that increases the baseline capacitance of the sensor. As for the change in Δfres upon 10% strain (Δfres = fres,baseline - fres,stretch), interestingly a larger change was observed for the damp configuration as compared to the baseline and dried (1.08 ± 0.08 vs 0.79 ± 0.06 vs 0.66 ± 0.03 MHz). A similar behaviour was observed in the test with pants, where the response for flexion was Δfres = 1.58 MHz for the damp sensor and Δfres = 1.28 MHz for the dried sensor. Discussion/Conclusion This preliminary investigation showed promising results in terms of robustness of our system to artificial sweat, as there was a measurable response both in the damp and dried configurations. Further tests with different sweat amounts and rate are needed to determine the full functioning range, e.g., how much sweat is tolerated. References Galli, V., Sailapu, S. K., Cuthbert, T. J., Ahmadizadeh, C., Hannigan, B. C., & Menon, C. (2023). Passive and wireless all-textile wearable sensor system. Advanced Science 10(22), Article 2206665. https://doi.org/10.1002/advs.202206665 Lin, R., Kim, H.-J., Achavananthadith, S., Xiong, Z., Lee, J. K. W., Kong, Y. L., & Ho, J. S. (2022). Digitally-embroidered liquid metal electronic textiles for wearable wireless systems. Nature Communications, 13, Article 2190. https://doi.org/10.1038/s41467-022-29859-4 Xu, L., Liu, Z., Zhai, H., Chen, X., Sun, R., Lyu, S., Fan, Y., Yi, Y., Chen, Z., Jin, L., Zhang, J., Li, Y., & Ye, T. T. (2020). Moisture-resilient graphene-dyed wool fabric for strain sensing. ACS Applied Materials & Interfaces, 12(11), 13265–13274. https://doi.org/10.1021/acsami.9b20964
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Larkin, Andrei V., and Alexander K. Fedotov. "Equivalent circuits of FeCoZr-alloy nanoparticles deposited into Al2O3 and PZT dielectric matrices nanogranular composite films." Journal of the Belarusian State University. Physics, no. 3 (October 27, 2022): 104–12. http://dx.doi.org/10.33581/2520-2243-2022-3-104-112.
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The paper presents equivalent substitution circuits (ESCs) describing nanogranular composite films (Fe0.45Cо0.45Zr0.10)x(Al2O3)1 – x and (Fe0.45Cо0.45Zr0.10)x(PZT)1 – x with a concentration of metal-containing granules in the range 0.3 < х < 0.8. Films of 2–7 μm thick were obtained by ion-beam sputtering of composite targets in pure argon or in Ar – O2 mixture, followed by stepwise (with a step of 25 K) isochronous (15 min) annealing in air in the temperature range of 398 – 873 K. Deposition of nanocomposites in an oxygen-containing atmosphere or subsequent annealing in air led to the formation of nanoparticles with a core – shell structure consisting of Fe0.45Cо0.45Zr0.10 metallic alloy cores coated with shells of native iron and cobalt oxides (FeO, Fe3O4, Fe2O3, CoO). It has been established that when such shells contain semiconductor-type iron oxides (like FeO and Fe3O4) the frequency dependences of the total impedance Z (f, T) of nanocomposites can be described using ESCs containing two resonant RCL-circuits, that is accompanied by a positive phase shift of the current relative to the applied bias voltage (the so-called negative capacitance effect). The prevailing of dielectric-like oxides (Fe2O3) in shells around metallic cores leads to ESCs either with one resonant RCL-circuit or without it at all. This results in disappearing of the negative capacitance effect when usual capacitive-like behaviour of nanocomposite behaviour is observed. It is shown that if we construct ESCs for nanocomposites with different ratios of the metallic (FeCoZr) and dielectric (Al2O3, PZT) components, it is possible to describe the Z (f, T) dependences for every circuit elements (R, C, L) corresponding both to individual phase components in nanocomposites including intrinsic semiconductor- or dielectric-like iron and cobalt oxides in shells around metallic cores.
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Farooq, Muhammad, Talha Iqbal, Patricia Vazquez, et al. "Thin-Film Flexible Wireless Pressure Sensor for Continuous Pressure Monitoring in Medical Applications." Sensors 20, no. 22 (2020): 6653. http://dx.doi.org/10.3390/s20226653.
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Physiological pressure measurement is one of the most common applications of sensors in healthcare. Particularly, continuous pressure monitoring provides key information for early diagnosis, patient-specific treatment, and preventive healthcare. This paper presents a thin-film flexible wireless pressure sensor for continuous pressure measurement in a wide range of medical applications but mainly focused on interface pressure monitoring during compression therapy to treat venous insufficiency. The sensor is based on a pressure-dependent capacitor (C) and printed inductive coil (L) that form an inductor-capacitor (LC) resonant circuit. A matched reader coil provides an excellent coupling at the fundamental resonance frequency of the sensor. Considering varying requirements of venous ulceration, two versions of the sensor, with different sizes, were finalized after design parameter optimization and fabricated using a cost-effective and simple etching method. A test setup consisting of a glass pressure chamber and a vacuum pump was developed to test and characterize the response of the sensors. Both sensors were tested for a narrow range (0–100 mmHg) and a wide range (0–300 mmHg) to cover most of the physiological pressure measurement applications. Both sensors showed good linearity with high sensitivity in the lower pressure range <100 mmHg, providing a wireless monitoring platform for compression therapy in venous ulceration.
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Guduloglu, Utku, Sedat Kurnaz, Turgay Seydioglu, Gizem Bekar, and Ozgur Ozturk. "Frequency Dependent Negative Dielectric Behavior in Parylene C Based Composite Films." Journal of Advanced Applied Sciences 3, no. 1 (2024): 32–39. http://dx.doi.org/10.61326/jaasci.v3i1.254.
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Dielectric materials are an important research topic for many applications today. Polymers are among the prominent dielectrics due to their durability, high ionic conductivity and low dielectric losses. This study investigates the dielectric properties of Parylene C (PAC)-based composite films. Capacitance and dissipation factor values are measured. Dielectric permittivity and losses are calculated. Negative capacitance and negative dielectric constant are observed, and resonant frequency values are compared. Activated carbon doping significantly impacts the resonant frequencies of the films. Doped samples exhibit higher positive and negative resonant frequencies (2.2560 MHz and 2.2593 MHz) compared to undoped counterparts (2.1952 MHz and 2.2015 MHz). Polarization further increases resonant frequencies, alongside dielectric permittivity and dissipation factor with permittivity experiencing a more pronounced increase. Post-polarization, doped samples display resonant frequencies of 2.3727 MHz and 2.3761 MHz, while undoped samples reach 2.3658 MHz and 2.3727 MHz. A comprehensive analysis of impedance, resistance, and reactance values reveals insights into the composite film's behavior. Crucially, throughout the measurements, the composite films display a consistent inductive response at frequencies above their resonance frequencies. Understanding the mechanisms behind this inductive response could open up new possibilities for the use of these films in advanced electronic devices and circuits.
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Xining, Zhao, Zhang Yongwang, Li Bo, Shen Chuangshi, Li Zewei, and Zhou Bo. "Active tuning of the vibration and wave propagation properties in electromechanical metamaterial beam." Journal of Applied Physics 132, no. 23 (2022): 234501. http://dx.doi.org/10.1063/5.0122301.
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Locally resonant metamaterial beams made from flexible substrates with piezoelectric layers can exhibit bandgap and vibration attenuation properties. However, the bandgap properties of the electromechanical metamaterials are limited by the electromechanical coupling coefficient. In order to effectively overcome this limitation of the locally resonant bandgaps, a locally resonant electromechanical metamaterial beam with piezoelectric actuators and sensors is presented, and the piezoelectric shunting technique and negative proportional feedback control strategy are combined. In this design, both negative capacitance ( NC) and inductance ( L) are incorporated into the shunt circuits. Then, the classical root locus method is employed to obtain single/multiple bandgaps and particular structural response by arranging the poles and zeros. Finally, the influences of the feedback control gain, the shunt circuit type, and the damping ratio on the bandgap properties and wave propagation behaviors are analyzed. Numerical results demonstrate that the single/multiple bandgaps can be obviously broadened by properly increasing the control gain. Specifically, adding negative capacitance in series to pure inductive circuit can generate wider absolute bandgaps at lower frequencies. The comparison of the frequency response and the bandgap characteristics reveals a very good agreement. Summarily speaking, combining the piezoelectric shunting technique and negative proportional feedback control strategy can effectively tune the vibration and wave propagation behavior.
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Zini, Marco, Marco Baù, Alessandro Nastro, Marco Ferrari, and Vittorio Ferrari. "Flexible Passive Sensor Patch with Contactless Readout for Measurement of Human Body Temperature." Biosensors 13, no. 6 (2023): 572. http://dx.doi.org/10.3390/bios13060572.
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A passive flexible patch for human skin temperature measurement based on contact sensing and contactless interrogation is presented. The patch acts as an RLC resonant circuit embedding an inductive copper coil for magnetic coupling, a ceramic capacitor as the temperature-sensing element and an additional series inductor. The temperature affects the capacitance of the sensor and consequently the resonant frequency of the RLC circuit. Thanks to the additional inductor, the dependency of the resonant frequency from the bending of the patch has been reduced. Considering a curvature radius of the patch of up to 73 mm, the maximum relative variation in the resonant frequency has been reduced from 812 ppm to 7.5 ppm. The sensor has been contactlessly interrogated by a time-gated technique through an external readout coil electromagnetically coupled to the patch coil. The proposed system has been experimentally tested within the range of 32–46 °C, giving a sensitivity of −619.8 Hz/°C and a resolution of 0.06 °C.
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Shen, Dong‐Lin, Li Zhang, Zi‐Bin Weng, Chu‐Hui Chen, and Yong‐Chang Jiao. "Compact monopole with a band‐stop matching circuit for LTE/WWAN smartphone." Microwave and Optical Technology Letters 60, no. 10 (2018): 2357–63. http://dx.doi.org/10.1002/mop.31365.
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AbstractAn LTE/WWAN monopole antenna with a compact size of 12.5 × 28.7 mm2 for smartphone applications is designed. The antenna is formed by an L‐shape driven branch, a parasitic shorting branch, and a band‐stop matching circuit. By capacitive coupling and loading a matching circuit, the antenna generates four resonant modes in the working bands. The band‐stop matching circuit is applied to enlarge the bandwidth of the low working band. The measured −6 dB impedance bandwidth of the presented antenna ranges from 683 MHz to 962 MHz and from 1632 MHz to 2710 MHz, covering LTE/WWAN eight‐band operation. Acceptable radiation performances are achieved over the working bands. The measured efficiencies are 45.4%‐61.2% and 44.5%‐66.4% and the measured gains are −0.6 dBi‐2.0 dBi and 0.07 dBi‐2.69 dBi in the low and high working band, respectively.
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CAN, Erol. "The Load Performance of Multi-Level Alternating Voltage Provided by Upgrade Effect." Jurnal Kejuruteraan 31, no. 2 (2019): 249–59. http://dx.doi.org/10.17576/jkukm-2019-31(2)-09.
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In this paper, the applications of the multi-level inverter with a partial inductor are investigated on different loads. The operation of the inverter is given according to different conditions of the circuit at the six-part duty times. Mathematical equations for the inverter are forming according to the load which is resistive (R), inductive (L), and Capacitive (C) in serial connection. After describing the circuit structure, Matlab SIMULİNK also simulates the circuit for loads that are RLC, and a single-phase asynchronous motor. While the voltage and current measurements for the RLC load are performed; measurements of the main winding current, auxiliary winding current, electromagnetic torque, speed are made on the asynchronous motor. RLC loads are operated at high current values such as 297A in order to examine the suitability of the proposed system for systems that may require high current. When the current harmonic distortions of RLC loads are observed, the distortion values are acceptable values that are lower than % 5 that is international standards of the IEEE. In another hand, despite the voltage is insufficient for supplying the motor at the motor application, the voltage is upgraded with the boost effect of the inverter. So, the voltage is both a multilevel and sufficient. According to the obtained results, it is shown that multi-level inverter design has been successfully performed by using partial inductor source.
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Xie, Yafei, Ji Fan, Chun Zhao, Shitao Yan, Chenyuan Hu, and Liangcheng Tu. "Modeling and Analysis of the Noise Performance of the Capacitive Sensing Circuit with a Differential Transformer." Micromachines 10, no. 5 (2019): 325. http://dx.doi.org/10.3390/mi10050325.
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Capacitive sensing is a key technique to measure the test mass movement with a high resolution for space-borne gravitational wave detectors, such as Laser Interferometer Space Antenna (LISA) and TianQin. The capacitance resolution requirement of TianQin is higher than that of LISA, as the arm length of TianQin is about 15 times shorter. In this paper, the transfer function and capacitance measurement noise of the circuit are modeled and analyzed. Figure-of-merits, including the product of the inductance L and the quality factor Q of the transformer, are proposed to optimize the transformer and the capacitance measurement resolution of the circuit. The LQ product improvement and the resonant frequency augmentation are the key factors to enhance the capacitance measurement resolution. We fabricated a transformer with a high LQ product over a wide frequency band. The evaluation showed that the transformer can generate a capacitance resolution of 0.11 aF/Hz1/2 at a resonant frequency of 200 kHz, and the amplitude of the injection wave would be 0.6 V. This result supports the potential application of the proposed transformer in space-borne gravitational wave detection and demonstrates that it could relieve the stringent requirements for other parameters in the TianQin mission.
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Ban, Yong-Ling, Shun Yang, Joshua Le-Wei Li, and Rui Li. "Printed Internal Pentaband WWAN Antenna Using Chip-Inductor-Loaded Shorting Strip for Mobile Phone Application." International Journal of Antennas and Propagation 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/516487.
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A compact size on-board printed antenna using capacitive coupled-fed excitation to generate multiple resonant modes for penta-band WWAN operation (GSM850/900/GSM1800/1900/UMTS2100) is presented in this paper. The proposed antenna occupies only a small footprint of 15 × 25 mm2on one corner of the circuit board and a protruded ground of 10 × 15 mm2is displaced with close proximity to the antenna portion. The proposed antenna has a very simple structure which is composed of two separate strips: a loop strip with an inserted chip inductor and an L-shaped feeding strip. The loop strip is shorted to the ground and generates a resonant mode at 890 MHz to cover the GSM850/900 band (824–960 MHz) while the feeding strip contributes to the GSM1800/1900/UMTS210 band (1710–2170 MHz) operation. With such a small size, the proposed antenna can achieve compact integration on the circuit board of the mobile phone, thus the proposed scheme is quite suitable for the slim mobile phone application. Good agreements between simulations and measurements are obtained. Details of proposed antenna are presented and some key parameters are studied.
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Kaloyeros, Alain, Mircea R. Stan, Barry Arkles, et al. "Conformational Molecular Switches for Post-CMOS Nanoelectronics." TRANSACTIONS ON CIRCUITS AND SYSTEMS 53, no. 11 (2007): 2345–52. https://doi.org/10.1109/TCSI.2007.907827.
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Theoretical treatments forecast that bistable CMOS devices using electronic charge as a state variable will operate at their maximum thermal dissipation limit possibly as early as 2012. The problem is further compounded by increasing manufacturing challenges associated with the ever decreasing logic switch dimensions. These challenges require the development of new fabrication strategies that replace or complement current top-down lithography with bottom-up protocols using controlled self-assembly of nanomaterial building blocks. To answer some of these issues, this paper focuses on a new device paradigm consisting of an arene-metal-arene conformational switch, addressable through capacitive, inductive, or resonant-tunneling field coupling. The operating principle is based on voltage-tunable modulation in quantum electron transmission. The switch is open (off) when the metal ion is displaced to a position at a C-H bond on the arene ring due to an externally applied bias. Conversely, when the external bias is removed, the metal ion moves to an axis- symmetric position on the arene ring, and the switch is closed (on). The paper presents a summary of the architecture, operating principle, and advantages of the conformational switch, along with associated findings from proof-of-concept theoretical and experimental studies of its target specifications and performance. The paper also discusses opportunities and challenges related to the integration of conformational switches into hybrid CMOS-molecular and monolithic (all molecular) circuits.
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Shan, Boyang, Haipeng Fu, and Jian Wang. "A Highly Integrated C-Band Feedback Resistor Transceiver Front-End Based on Inductive Resonance and Bandwidth Expansion Techniques." Micromachines 15, no. 2 (2024): 169. http://dx.doi.org/10.3390/mi15020169.
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This paper presents a highly integrated C-band RF transceiver front-end design consisting of two Single Pole Double Throw (SPDT) transmit/receive (T/R) switches, a Low Noise Amplifier (LNA), and a Power Amplifier (PA) for Ultra-Wideband (UWB) positioning system applications. When fabricated using a 0.25 μm GaAs pseudomorphic high electron mobility transistor (pHEMT) process, the switch is optimized for system isolation and stability using inductive resonance techniques. The transceiver front-end achieves overall bandwidth expansion as well as the flat noise in receive mode using the bandwidth expansion technique. The results show that the front-end modules (FEM) have a typical gain of 22 dB in transmit mode, 18 dB in receive mode, and 2 dB noise in the 4.5–8 GHz band, with a chip area of 1.56 × 1.46 mm2. Based on the available literature, it is known that the proposed circuit is the most highly integrated C-band RF transceiver front-end design for UWB applications in the same process.
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Ren, Zhong, Qiu Lin Tan, Chen Li, Tao Luo, Ting Cai, and Ji Jun Xiong. "The Design and Simulation of Wide Range Pressure Sensor Based on HTCC for High-Temperature Applications." Key Engineering Materials 609-610 (April 2014): 1053–59. http://dx.doi.org/10.4028/www.scientific.net/kem.609-610.1053.
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A wide range pressure sensor is designed based on the theoretical basis of LC series resonance circuit model to realize the wireless passive measurement in the harsh environment, such as high temperature and high pressure. The capacitive pressure sensitive device is devised by the technology of high-temperature co-fired ceramics (HTCC) to form nine density cavities in zirconia ceramic substrates, and thick film technology to print capacitance plates and planar spiral inductors. The theoretical calculation and simulation analysis of the designed sensor are made respectively under high pressure (10MPa) and temperature (600 °C), the results of which verify the feasibility of the design in a wide range of pressure for high-temperature applications, and provide the reliable theory basis for the fabrication of wide range pressure sensor.
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Büyüktas, Kevni, Klaus Koller, Karl-Heinz Müller, and Angelika Geiselbrechtinger. "A New Process for On-Chip Inductors with High Q-Factor Performance." International Journal of Microwave Science and Technology 2010 (October 5, 2010): 1–9. http://dx.doi.org/10.1155/2010/517187.
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A novel technological method to improve the quality factor (Q) of RF-integrated inductors for wireless applications is presented in this paper. A serious reduction of substrate losses caused by capacitive coupling is provided. This is realised by removing the oxide layers below the coils with optimized underetching techniques. This special etching procedure is used to establish an environment in the inductor substructure with very low permittivity. A set of solid oxide-metal-columns placed below the metal windings stabilize the coil and prevent the hollowed out structure from mechanical collapse. The oxide capacitance is lowered significantly by the reduction of the permittivity from values around 4 to nearly 1. Capacitive coupling losses into substrate are decreasing in the same ratio. The resulting maximum Q-factors of the new designs are up to 100% higher compared to the same devices including the oxide layers but shifted significantly to higher frequencies. Improvements of Q from 10 up to 15 have been obtained at a frequency of 3 GHz for a 2.2 nH inductor with an outer diameter of 213 m. The resonance frequency () and frequency at maximum Q () are shifted to higher frequencies, caused by the shrunk total capacitance of the structure. This enables the circuit designer to use the inductors for applications working at higher frequencies. Coils with different layouts and values for inductance (L) were verified and showed similar results.
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Zhu, Bao-Hua, Nam-Young Kim, Zhi-Ji Wang, and Eun-Seong Kim. "On-Chip Miniaturized Bandpass Filter Using GaAs-Based Integrated Passive Device Technology For L-Band Application." Materials 12, no. 18 (2019): 3045. http://dx.doi.org/10.3390/ma12183045.
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In this work, a miniaturized bandpass filter (BPF) constructed of two spiral intertwined inductors and a central capacitor, with several interdigital structures, was designed and fabricated using integrated passive device (IPD) technology on a GaAs wafer. Five air-bridge structures were introduced to enhance the mutual inductive effect and form the differential geometry of the outer inductors. In addition, the design of the differential inductor combined with the centrally embedded capacitor results in a compact construction with the overall size of 0.037λ0 × 0.019λ0 (1537.7 × 800 μm2) where λ0 is the wavelength of the central frequency. For the accuracy evolution of the equivalent circuit, the frequency-dependent lumped elements of the proposed BPF was analyzed and modeled through the segment method, mutual inductance approach, and simulated scattering parameters (S-parameters). Afterward, the BPF was fabricated using GaAs-based IPD technology and a 16-step manufacture flow was accounted for in detail. Finally, the fabricated BPF was wire-bonded with Au wires and packaged onto a printed circuit board for radio-frequency performance measurements. The measured results indicate that the implemented BPF possesses a center frequency operating at 2 GHz with the insertion losses of 0.38 dB and the return losses of 40 dB, respectively, and an ultrawide passband was achieved with a 3-dB fraction bandwidth of 72.53%, as well. In addition, a transmission zero is located at 5.32 GHz. Moreover, the variation of the resonant frequency with different inductor turns and metal thicknesses was analyzed through the simulation results, demonstrating good controllability of the proposed BPF.
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Bukhari, Syed Ali Raza, Muhammad Mubasher Saleem, Umar Shahbaz Khan, Amir Hamza, Javaid Iqbal, and Rana Iqtidar Shakoor. "Microfabrication Process-Driven Design, FEM Analysis and System Modeling of 3-DoF Drive Mode and 2-DoF Sense Mode Thermally Stable Non-Resonant MEMS Gyroscope." Micromachines 11, no. 9 (2020): 862. http://dx.doi.org/10.3390/mi11090862.
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This paper presents microfabrication process-driven design of a multi-degree of freedom (multi-DoF) non-resonant electrostatic microelectromechanical systems (MEMS) gyroscope by considering the design constraints of commercially available low-cost and widely-used silicon-on-insulator multi-user MEMS processes (SOIMUMPs), with silicon as a structural material. The proposed design consists of a 3-DoF drive mode oscillator with the concept of addition of a collider mass which transmits energy from the drive mass to the passive sense mass. In the sense direction, 2-DoF sense mode oscillator is used to achieve dynamically-amplified displacement in the sense mass. A detailed analytical model for the dynamic response of MEMS gyroscope is presented and performance characteristics are validated through finite element method (FEM)-based simulations. The effect of operating air pressure and temperature variations on the air damping and resulting dynamic response is analyzed. The thermal stability of the design and corresponding effect on the mechanical and capacitive sensitivity, for an operating temperature range of −40 °C to 100 °C, is presented. The results showed that the proposed design is thermally stable, robust to environmental variations, and process tolerances with a wide operational bandwidth and high sensitivity. Moreover, a system-level model of the proposed gyroscope and its integration with the sensor electronics is presented to estimate the voltage sensitivity under the constraints of the readout electronic circuit.
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Stoecklin, Sebastian, Adnan Yousaf, Gunnar Gidion, Leonhard Reindl, and Stefan J. Rupitsch. "Simultaneous Power Feedback and Maximum Efficiency Point Tracking for Miniaturized RF Wireless Power Transfer Systems." Sensors 21, no. 6 (2021): 2023. http://dx.doi.org/10.3390/s21062023.
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Near-field interfaces with miniaturized coil systems and low output power levels, such as applied in biomedical sensor systems, can suffer from severe efficiency degradation due to dynamic impedance mismatches, reducing battery life of the power transmitter unit and requiring to increase the level of electromagnetic emission. Moreover, the stability of weakly-coupled power transfer systems is generally limited by transient changes in coil alignment and load power consumption. Hence, a central research question in the domain of wireless power transfer is how to realize an adaptive impedance matching system under the constraints of a simultaneous power feedback to increase the system’s efficiency and stability, while maintaining circuit characteristics such as small size, low power consumption and fast reaction times. This paper presents a novel approach based on a two-stage control loop implemented in the primary-side reader unit, which uses a digital PI controller to maintain the rectifier output voltage for power feedback and an on-top perturb-and-observe controller configuring the setpoint of the voltage controller to maximize efficiency. The paper mathematically analyzes the AC and DC transfer characteristics of a resonant inductive link to design the reactive AC matching network, the digital voltage controller and ultimately the DC-domain impedance matching algorithm. It was found that static reactive L networks result in suitable efficiency levels for coils with sufficiently high quality factor even without adaptive tuning of operational frequency or reactive components. Furthermore, the regulated output voltage of the rectifier is a direct measure of the DC load impedance when using a regular DC/DC converter to supply the load circuits, so that this quantity can be tuned to maximize efficiency. A prototype implementation demonstrates the algorithms in a 40.68 MHz inductive link with load power levels from 10 to 100 mW and tuning time constants of 300 ms, while allowing for a simplified receiver with a footprint smaller than 200 mm2 and a self-consumption below 1 mW. Hence, the presented concepts enable adaptive impedance matching with favorable characteristics for low-energy sensor systems, i.e., minimized footprint, power level and reaction time.
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Oskolkov, Alexander A., Igor I. Bezukladnikov, and Dmitriy N. Trushnikov. "Rapid Temperature Control in Melt Extrusion Additive Manufacturing Using Induction Heated Lightweight Nozzle." Applied Sciences 12, no. 16 (2022): 8064. http://dx.doi.org/10.3390/app12168064.
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An approach for improving and maintaining consistent fusion quality of the deposited material during FDM 3d-printing is proposed. This approach is based on the nozzle temperature control during the printing process to adjust the polymer extrusion temperature with a speed and accuracy adequate to the FDM process. High frequency induction heating of the lightweight nozzle (<1 g) was used. To control the temperature of a lightweight nozzle, the resonant temperature measurement method based on the analysis of the high frequency eddy currents is proposed. To determine the parameters of the nozzle and the inductor as a plant, a FEM model of the inductive heating of the nozzle and a simulated model of a serial-parallel resonant circuit containing inductor were developed. Linearization of the automatic control system was performed to ensure the equal quality of regulation when operating in a wide temperature range. The quality of regulation, stability of the system, and coefficients of the PID controller were evaluated using a simulated model of the control system. A number of test samples were printed from various materials, and tensile stress testing was carried out. The developed control method reduces the nozzle temperature control error from 20 to 0.2 °C and decreases control delay by more than six times.
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Yung, Kaung-Ti. "A Birdcage Model for the Chinese Meridian System Part I: A Channel as a Transmission Line." American Journal of Chinese Medicine 32, no. 05 (2004): 815–28. http://dx.doi.org/10.1142/s0192415x04002417.
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The concept of Qi and the concept of channel are so closely related that they must be defined and comprehended simultaneously in a coordinated fashion. Once the nature of Qi is established in terms of physics, we may be able to explain the functional role that the channels play, as well as explain other Chinese medical terminology with a language of modern science. Based on the low electrical impedance characteristics of acupoints, we propose that the meridian channel is equivalent to an electromagnetic transmission line and the Qi is the electromagnetic (EM) standing wave riding on the line, with acupoints as its nodes. The standing wave within each segment of the channel separated by acupoints is in natural oscillation thus the segment may be analyzed as a λ/4 open circuit that behaves like a series RLC resonator. Acupuncture until De Qi is effectively equivalent to charging the capacitor C eq of the RLC resonator in the transmission line. The mechanism of bu and xie are charging or discharging the capacitor to bring the capacititive (or inductive) behavior of the segment back to that of the resonant state. Kirlian photograph may serve as a visual observation of the EM waves on channels.
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Rodriguez, Rogie I., and Yi Jia. "A wireless inductive-capacitive (L-C) sensor for rotating component temperature monitoring." International Journal on Smart Sensing and Intelligent Systems 4, no. 2 (2011). https://doi.org/10.21307/ijssis-2017-442.
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Temperature monitoring is critical in almost every type of machinery and application, especially in rotating components such as jet turbines, engines, and power plants, etc. These components involve harsh environments and where the physical connections for monitoring systems are impossible. This paper presents a resonant inductive-capacitive (L-C) circuit based wireless temperature sensor suitable for working in these harsh environments to monitor the temperature of rotating components. Design and performance analysis of the wireless temperature sensor has been conducted and the sensor prototype was successfully fabricated and calibrated up to 200ºC with sensitivity of 30 kHz/ºC. As a result it is confirmed that temperature monitoring of a rotating component can be carried out without requiring physical connection, power supplies or active elements in the sensor circuit.
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"FPGA based Hybrid Resonant Switching DC/DC converter for Electric Vehicles." International Journal of Innovative Technology and Exploring Engineering 8, no. 9 (2019): 334–40. http://dx.doi.org/10.35940/ijitee.e3135.078919.
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The cerebrum tumors are the most well-known and forceful sickness, prompting an extremely short future in their most noteworthy evaluation. Accordingly, treatment arranging is a key stage to improve the personal satisfaction of patients. Generally, various medical image modalities like Magnetic Resonance Imaging (MRI), Computed Tomography (CT) and ultrasound image are used to evaluate the cerebrum tumor in a brain, lung, liver, breast, prostate etc. MRI images are very much useful for different types of brain tumor exposure and segmentation. A plethora of methods like k-means clustering, Fuzzy C-Means, SOM clustering, Deep Convolution Neural Networks (DNN), SVM, Convolutional Neural Networks (CNN) for cerebrum brain tumor detection from MRI images. This paper concentrated on mind cerebrum tumor recognition calculations that have been planned so distant to recognize the area of the cerebrum tumor.A hybrid switching DC-DC converter for Hybrid Electric Vehicle with reduced on state conduction losses, voltage stress and switching losses of the power semiconductor devices is presented in this paper. Zero current switching and zero voltage switching is achieved for the leading and lagging legs of the inverter by using bipolar switching method. This reduces the circulatory losses in the transformer primary. Additionally it aids in exploiting the leakage inductance of the transformer to resonate with the output capacitor. Consequently this reduces the components count and the converter size. This results in efficient energy transfer as the inductive energy and capacitive energy acquired by the output inductor and resonant capacitor are simultaneously transferred to the load during the freewheeling interval. This boosts the converter efficiency when compared to the conventional converter. During active intervals, inductor is charged and the increased capacitor voltage is offered to the load. The bipolar circuit voltage is clamped during the freewheeling interval and reduces the peak voltage overshoots that crop up during the diode reverse bias period. Simulation for the DC-DC converter is rendered with PSpice software and the experimental results shows the desired output is achieved with reduced losses under variable load conditions.
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Yue, Yonghui, Zhenao Sun, and Mingyu Lu. "Power stabilization control of wireless charging system based on LCL‐P compensation structure." International Journal of Circuit Theory and Applications, August 27, 2024. http://dx.doi.org/10.1002/cta.4250.
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AbstractTo enhance the stabilizing function and boost the output power of the inductive coupling power transfer (ICPT) system, a power stabilization control method based on LCL‐P resonance compensation for a wireless energy transmission system is proposed. “L” represents inductance, “C” represents capacitance, “LCL” refers to the primary‐side compensation structure, and “P” indicates that the secondary side is compensated in parallel . Firstly, this paper synthesizes the modeling principle of the gyrator equivalent model of the resonant circuit and coupled inductor, graphically analyzes the resonant compensation structure, and derives the circuit characteristics of the LCL‐P compensation structure. Then, this paper proposes an improved control strategy for the Maximum Power Point Tracking (MPPT) algorithm to dynamically track the output power and thus obtain the optimal operating point through frequency conversion. Lastly, using MATLAB/Simulink software to build the simulation model of the wireless charging system through parameter design, the impact of the conventional DC/DC power control method is contrasted with the algorithmic control suggested in this paper. The results demonstrate that: the device can realize power transfer of 2.7 KW level, the energy transfer efficiency reaches more than 90%, the inverter realizes soft‐switching operation, and the improved MPPT algorithmic control strategy proposed in this paper is utilized to achieve better closed‐loop control of the system. The excellent characteristics of the LCL‐P compensation structure in high‐power transmission applications, as well as the correctness and feasibility of the control algorithm proposed in this paper, are demonstrated through simulation and practical experiments. This is a significant step towards improving the wide‐range adaptation of the wireless charging system, which is based on the LCL‐P resonance compensation to the changes in the load and coupling.
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Van Kann, Frank J., and Alexey V. Veryaskin. "A Novel Capacitive Sensor Interface Based on a Simple Capacitance-to-Phase Converter." Measurement Science and Technology, July 23, 2024. http://dx.doi.org/10.1088/1361-6501/ad6681.
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Abstract A novel room temperature capacitive sensor interface circuit is proposed and successfully tested, which uses a modified All-Pass filter architecture combined with a simple series resonant tank circuit with a moderate Q-factor. It is fashioned from a discrete inductor with small dissipation resonating with a grounded capacitor acting as the sensing element to obtain a resolution of ∆C ~ 2 zF in a capacitance range of 10 – 30 pF. The circuit converts the change in capacitance to the change in the phase of a carrier signal in a frequency range with a central frequency set up by the tank circuit’s resonant frequency and is configured to act as a close approximation of the ideal All-Pass filter. This cancels out the effects of amplitude modulation when the carrier signal is imperfectly tuned to the resonance. The proposed capacitive sensor interface has been specifically developed for use as a front-end constituent in ultra-precision mechanical displacement measurement systems, such as accelerometers, seismometers, gravimeters and gravity gradiometers, where moving plate grounded air gap capacitors are frequently used. Some other applications of the proposed circuit are possible including the measurement of the electric field, where the sensing capacitor depends on the applied electric field, and cost effective capacitive gas sensors. In addition, the circuit can be easily adapted to function with very small capacitance values (1 - 2 pF) as is typical in MEMS-based transducers.
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Akhiyarov, V. V. "Analysis of two-dimensional planar gratings and metasurfaces in the quasi-static approximation." Radioengineering, July 7, 2024. http://dx.doi.org/10.18127/j00338486-202407-25.
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Currently, composite materials based on metal gratings with a period D much smaller than the wavelength l are widely used. With the use of such materials, it is possible to control the amplitude, phase and polarization of an electromagnetic wave, which opens wide possibilities for the creation of new types of antennas, radio-absorbing coatings, etc. This paper considers gratings of metallic strip or patches on the surface of a thin metal-backed dielectric slab to control the phase of the reflected wave. In the quasi-static approximation, the input impedance of such materials can be calculated using simple analytical formulas. This paper investigates the accuracy of the quasi-static approximation at different angles of incidence of the electromagnetic wave on two-dimensional gratings. Using the equivalent circuits method, analytical expressions for the input impedance of metasurfaces are obtained. The dispersion properties of composite materials “inductive or capacitive grating on the surface of a thin metal-backed dielectric slab” are investigated, and a technique for determining the resonant frequency, which corresponds to the maximum of the input impedance of the metasurface, is presented. The obtained results show that at any angle of incidence, it is possible to evaluate the condition of the quasi-static approximation applicability for two-dimensional gratings and for metasurfaces based on such gratings. If this condition is satisfied, that simple analytical expressions can be used to calculate the input impedance. The use of these expressions allows us to determine the frequency at which the input impedance reaches its maximum. It is established that for inductive and capacitive gratings the impedance boundary condition of M.A. Leontovich is equivalent to the averaged boundary condition of M.I. Kontorovich. It is obtained that for grating in free space, quasi-static approximation corresponds to the M.A. Leontovich impedance condition. The dispersion properties of composite materials “inductive or capacitive grating on a thin metal-backed dielectric slab” are investigated. It is shown that the phase transition of the reflection coefficient through zero occurs at maximum values of the input impedance. Using the considered method of equivalent circuits, the presented results can be easily generalized to any type of multilayer metasurfaces.
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Kuckla, Daniel Alexander, Julia-Sarita Brand, Bastian Czech, et al. "An efficient magnetothermal actuation setup for fast heating/cooling cycles or long-term induction heating of different magnetic nanoparticle classes." Journal of Physics D: Applied Physics, September 20, 2023. http://dx.doi.org/10.1088/1361-6463/acfb8f.
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Abstract Alternating magnetic fields (AMFs) in the ~100 kHz frequency regime cause magnetic nanoparticles (MNPs) to dissipate heat to their nanoscale environment. This mechanism is beneficial for a variety of applications in biomedicine and nanotechnology, such as localized heating of cancer tissue, actuation of drug release, or inducing conformational changes of molecules. However, engineering electromagnetic resonant circuits which generate fields to efficiently heat MNPs over long time scales, remains a challenge. In addition, many applications require fast heating/cooling cycles over ΔT = 5-10 °C to switch the sample between different states. Here, we present a home-built magnetothermal actuation setup maximized in its efficiency to deliver stable AMFs as well as to enable fast heating/cooling cycles of MNP samples. The setup satisfies various demands, such as an elaborate cooling system to control heating of the circuit components as well as of the sample due to inductive losses. Fast cycles of remote sample heating/cooling (up to ±15 °C/min) as well as long-term induction heating were monitored via contact-free thermal image recording at sub-mm resolution. Next to characterizing the improved hyperthermia setup, we demonstrate its applicability to heat different types of MNPs: ‘Nanoflower’-shaped multicore iron oxide nanoparticles, core shell magnetite MNPs, as well as Magnetosomes from magnetotactic bacteria (Magnetospirillum gryphiswaldense). MNPs are directly compared in their structure, surface charge, magnetic properties as well as heating response. Our work provides practical guidelines for AMF engineering and the monitoring of MNP heating for biomedical or nano-/biotechnological applications.&#xD;
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Osadchuk, Alexander, Neonila Osadchuk, and Jaroslav Osadchuk. "RADIOMEASURING GAS CONCENTRATION TRANSDUCER BASED ON TRANSISTOR STRUCTURE WITH NDR FOR THE DIAGNOSIS OF STRAINS OF THE BACTERIUM HELICOBACTER PYLORI." Visnyk Universytetu “Ukraina”, 2019. http://dx.doi.org/10.36994/2707-4110-2019-1-22-09.
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The article discusses a radiomeasuring gas concentration transducer for the diagnosis of strains of the bacterium Helicobacter pylori. One of the promising directions in the construction of gas concentration transducers for respiratory diagnostics is the use of gas concentration frequency transducers based on the reactive properties of transistor structures with negative differential resistance (NDR). This type of transducers allows you to solve the problem of using analog-to-digital converters, because it implements the method of converting "informative signal - frequency", which is one of the best for further processing on a computer. Theoretical and practical studies have shown that using the reactive properties of semiconductor devices and transistor structures in which there is a negative differential resistance, it is possible to significantly increase the sensitivity and accuracy of measuring gas concentration, in particular NH3. The authors proposed and studied a gas concentration measuring transducer, which is built on the basis of a transistor structure with negative differential resistance and a gas-sensitive element to NH3. With a change in gas concentration, the conductivity of the sensitive element changes, which adsorbs NH3 molecules, which in turn changes the active and reactive components of the impedance of the transistors structure. The reactive component of the impedance of the transistors structure is capacitive in nature. This capacitance is part of the total capacitance that occurs at the electrodes of the drain of a double-gate MOS transistor and collector of a bipolar transistor, which together with the inductance L form a resonant oscillatory circuit. A dynamic mathematical model of the frequency transducer of gas concentration by the method of variable states is developed. The dynamic model of the self-generating secondary transducer of gas concentration allows you to determine the value of the frequency of the output signal depending on the change in gas concentration at any time. Analytical expressions of the transformation function and sensitivity equations are obtained. The sensitivity of the developed device for the diagnosis of strains of the bacterium Helicobacter pylori ranges from 2.1 kHz/ppm to 3.4 kHz/ppm.
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Moniruzzaman, Md, Mohammad Tariqul Islam, Norbahiah Misran, Md Samsuzzaman, Touhidul Alam, and Muhammad E. H. Chowdhury. "Inductively tuned modified split ring resonator based quad band epsilon negative (ENG) with near zero index (NZI) metamaterial for multiband antenna performance enhancement." Scientific Reports 11, no. 1 (2021). http://dx.doi.org/10.1038/s41598-021-91432-8.
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AbstractAn inductively tuned modified split-ring resonator-based metamaterial (MTM) is presented in this article that provides multiple resonances covering S, C, X, and Ku-bands. The MTM is designed on an FR-4 substrate with a thickness of 1.5 mm and an electrical dimension of 0.063λ × 0.063λ where wavelength, λ is calculated at 2.38 GHz. The resonator part is a combination of three squared copper rings and one circular ring in which all the square rings are modified shaped, and the inner two rings are interconnected. The resonance frequency is tuned by adding inductive metal strips in parallel two vertical splits of the outer ring that causes a significant shift of resonances towards the lower frequencies and a highly effective medium ratio (EMR) of 15.75. Numerical simulation software CST microwave studio is used for the simulation and performance analysis of the proposed unit cell. The MTM unit cell exhibits six resonances of transmission coefficient (S21) at 2.38, 4.24, 5.98, 9.55, 12.1, and 14.34 GHz covering S, C, X, and Ku-bands with epsilon negative (ENG), near-zero permeability, and near-zero refractive index (NZI). The simulated result is validated by experiment with good agreement between them. The performance of the array of the unit cells is also investigated in both simulation and measurement. The equivalent circuit modeling has been accomplished using Advanced Design Software (ADS) that shows a similar S21 response compared to CST simulation. Noteworthy to mention that with the copper backplane, the same unit cell provides multiband absorption properties with four major absorption peaks of 99.6%, 95.7%, 99.9%, 92.7% with quality factors(Q-factor) of 28.4, 34.4, 23, and 32 at 3.98, 5.5, 11.73 and 13.47 GHz, respectively which can be applied for sensing and detecting purposes. The application of an array of the unit cells is investigated using it as a superstrate of an antenna that provides a 73% (average) increase of antenna gain. Due to its simple design, compact dimension with high EMR, ENG property with near-zero permeability, this multiband NZI metamaterial can be used for microwave applications, especially for multiband antenna gain enhancement.