- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Characterization of Graphite/ZnO Schottky Barriers Formed on Polar and Nonpolar ZnO Surfaces
摘要： The authors demonstrate that the electrical properties of Schottky junctions fabricated by the deposition of colloidal graphite strongly depend on the crystallographic orientation of the ZnO substrate. The current-voltage, capacitance-voltage, and impedance measurements indicate that near-ideal Schottky junctions form on c-plane, while on a- and m-plane the junctions are laterally inhomogeneous. This behavior is assigned to higher concentration of native point defects in the near-surface region of nonpolar ZnO substrates. The authors further present an extended equivalent circuit model, which corresponds to actual structure of the junctions, and sheds light on their electrical transport properties.
关键词： impedance spectroscopy,graphite,equivalent circuit,ZnO,crystal polarity,Schottky contact
更新于2025-09-23 15:21:01
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A Stretchable Metamaterial Absorber with Deformation Compensation Design at Microwave Frequencies
摘要： A stretchable microwave metamaterial absorber with specific pattern design is proposed and fabricated in this paper to improve the stability of microwave absorption for deformation. Compensation mechanism is revealed by the electrical current loop for resonance absorption excitation in equivalent circuit model. The proposed metamaterial absorber with slotted cross pattern is compared with the conventional cross pattern absorber. A stretchable silver conductive ink validates the silk screen printing of resistive patterns on flexible polydimethylsiloxane (PDMS) substrate and hence realizes the stretching experiments. In a 25% stretch, the resonant frequency of the compensated absorber shifts only 0.5% for TM polarization, comparing to the 8% shifting of the conventional structure.
关键词： Stretchable,compensation mechanism,metamaterial absorber,resistive patterns,equivalent circuit model
更新于2025-09-23 15:21:01
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Machine Learning Based Approaches for Modeling the Output Power of Photovoltaic Array in Real Outdoor Conditions
摘要： It is important to investigate the long‐term performances of an accurate modeling of photovoltaic (PV) systems, especially in the prediction of output power, with single and double diode models as the configurations mainly applied for this purpose. However, the use of one configuration to model PV panel limits the accuracy of its predicted performances. This paper proposes a new hybrid approach based on classification algorithms in the machine learning framework that combines both single and double models in accordance with the climatic condition in order to predict the output PV power with higher accuracy. Classification trees, k‐nearest neighbor, discriminant analysis, Na?ve Bayes, support vector machines (SVMs), and classification ensembles algorithms are investigated to estimate the PV power under different conditions of the Mediterranean climate. The examined classification algorithms demonstrate that the double diode model seems more relevant for low and medium levels of solar irradiance and temperature. Accuracy between 86% and 87.5% demonstrates the high potential of the classification techniques in the PV power predicting. The normalized mean absolute error up to 1.5% ensures errors less than those obtained from both single‐diode and double‐diode equivalent‐circuit models with a reduction up to 0.15%. The proposed hybrid approach using machine learning (ML) algorithms could be a key solution for photovoltaic and industrial software to predict more accurate performances.
关键词： prediction of performances,PV modules modeling,classification algorithms,equivalent‐circuit models,machine learning
更新于2025-09-23 15:19:57
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DEVELOPMENT OF AN EQUIVALENT CIRCUIT MODEL OF A FINITE GROUND COPLANAR WAVEGUIDE INTERCONNECT IN MIS SYSTEM FOR ULTRA-BROADBAND MONOLITHIC ICS
摘要： An equivalent circuit model of a ?nite ground plane coplanar waveguide (FGCPW) interconnect in a metal-insulator-semiconductor (MIS) system for an ultra-broadband monolithic IC is proposed and illustrated. An e?ective substrate considering Maxwell-Wagner Polarization is suggested and demonstrated. The method of modeling the weak skin e?ect of the conductor is presented. The accuracy of the equivalent circuit model is evaluated. This proposed FGCPW interconnect equivalent circuit model enables a quick and e?cient time domain simulation to estimate the time delay and bandwidth of ultra-broadband ICs.
关键词： FGCPW interconnect,MIS system,equivalent circuit model,weak skin effect,Maxwell-Wagner Polarization,ultra-broadband monolithic IC
更新于2025-09-23 15:19:57
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Design and equivalent circuit model extraction of a third-order band-pass frequency selective surface filter for terahertz applications
摘要： In this paper, a third-order band-pass frequency selective surface (FSS) filter is proposed for terahertz applications. The presented FSS filter is designed based on miniaturized unit cells and a fractional bandwidth of 72% around 0.775 THz is achieved. In addition, a high transmission magnitude is obtained with an acceptable flatness in comparison to previous reports. In order to verify the numerical results, an equivalent circuit model of the proposed spatial filter is introduced considering both normal and oblique incident angles. The sensitivity of the filter with respect to the incident wave angle is investigated in the range of 0–60° whereas the obtained performance is acceptable for various incident angles in the mentioned range. Moreover, the effects of altering different geometrical parameters are studied and justified based on the extracted equivalent circuit model.
关键词： Miniaturized elements,Terahertz filter,Equivalent circuit model,Metamaterial,Frequency selective surface
更新于2025-09-19 17:15:36
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Frequency Comb Generation at 800 nm in Waveguide Array Quantum Well Diode Lasers
摘要： A capacitive-piezoelectric transducer combines capacitive and piezoelectric mechanisms to achieve a combination of electromechanical coupling and Q higher than otherwise attainable by either mechanism separately, has allowed demonstration of a 1.2-GHz contour-mode aluminum nitride (AlN) ring resonator with Q > 3000 on par with the highest measured d31-transduced AlN-only piezoelectric resonators past 1 GHz, and a 50-MHz disk array with an even higher Q > 12 000. Here, the key innovation is to separate the piezoelectric resonator from its metal electrodes by tiny gaps to eliminate metal material and metal-to-piezoelectric interface losses thought to limit thin-film piezoelectric resonator Q, while also maintaining high electric field strength to preserve a strong piezoelectric effect. While Q increases, electromechanical coupling decreases, but the k2 · Q product can still increase overall. More importantly, use of the capacitive-piezo transducer allows a designer to trade electromechanical coupling for Q, providing a very useful method to tailor Q and coupling for narrowband radio frequency (RF) channel-selecting filters for which Q trumps coupling. This capacitive-piezo transducer concept does not require dc-bias voltages and allows for much thicker electrodes that reduce series resistance without mass loading the resonant structure. The latter is especially important as resonators and their supports continue to scale toward even higher frequencies.
关键词： electromechanical coupling,oscillator,Micromechanical resonator,self-alignment,small gap,aluminum nitride,equivalent circuit,quality factor,filter
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Dark Pulses in a Long Ring Laser
摘要： A capacitive-piezoelectric transducer combines capacitive and piezoelectric mechanisms to achieve a combination of electromechanical coupling and Q higher than otherwise attainable by either mechanism separately, has allowed demonstration of a 1.2-GHz contour-mode aluminum nitride (AlN) ring resonator with Q > 3000 on par with the highest measured d31-transduced AlN-only piezoelectric resonators past 1 GHz, and a 50-MHz disk array with an even higher Q > 12 000. Here, the key innovation is to separate the piezoelectric resonator from its metal electrodes by tiny gaps to eliminate metal material and metal-to-piezoelectric interface losses thought to limit thin-film piezoelectric resonator Q, while also maintaining high electric field strength to preserve a strong piezoelectric effect. While Q increases, electromechanical coupling decreases, but the k2 · Q product can still increase overall. More importantly, use of the capacitive-piezo transducer allows a designer to trade electromechanical coupling for Q, providing a very useful method to tailor Q and coupling for narrowband radio frequency (RF) channel-selecting filters for which Q trumps coupling. This capacitive-piezo transducer concept does not require dc-bias voltages and allows for much thicker electrodes that reduce series resistance without mass loading the resonant structure. The latter is especially important as resonators and their supports continue to scale toward even higher frequencies.
关键词： electromechanical coupling,oscillator,Micromechanical resonator,self-alignment,small gap,aluminum nitride,equivalent circuit,quality factor,filter
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Monolayer of Plasmonic Nanolaser: a Study of Spasing Regime and Polarization Characteristics
摘要： An injection-locked magnetron with an external oscillator was investigated to obtain the parameters of the equivalent circuit model. The magnetron was locked over the ratio of the input power to output power of ?26 dB and had the resonance characteristics of a parallel LCR circuit model. Increasing the input power caused the anti-resonance frequency to become the original frequency of the magnetron; the range of the locking frequency was wider because of the lower Q value. The phase noise of the locked magnetron of ?70 dBc at a 40-kHz offset was improved in comparison with an unlocked magnetron. The results show that an injection-locked magnetron with an external oscillator has great potential for obtaining a high power output.
关键词： frequency locking,injection-locked magnetron,Equivalent circuit model of magnetron
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Ottawa, ON, Canada (2019.7.8-2019.7.12)] 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Compact transmission-line equivalent circuit model for silicon solar cell simulation
摘要： We demonstrate a compact equivalent circuit model for transmission-line representation of monocrystalline silicon solar cell. The model for solar cell characterization in terms of impedance/admittance spectroscopy. Number of coordinate partition elements necessary to adequately represent the device characteristics is reasonably comparable with the number of solar cell structure epi-layers. This makes the model convenient for transient effect simulations in external electrical circuits where fully distributed transmission-line model is too complex for direct time-domain calculations.
关键词： numerical simulation,optoelectronic devices,solar cells,equivalent circuit model,impedance spectroscopy
更新于2025-09-19 17:13:59
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[IEEE 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2019.11.25-2019.11.27)] 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Study on 3D thermal transport in micro-LEDs on GaN substrate at the level of kW/cm <sup>2</sup>
摘要： An injection-locked magnetron with an external oscillator was investigated to obtain the parameters of the equivalent circuit model. The magnetron was locked over the ratio of the input power to output power of ?26 dB and had the resonance characteristics of a parallel LCR circuit model. Increasing the input power caused the anti-resonance frequency to become the original frequency of the magnetron; the range of the locking frequency was wider because of the lower Q value. The phase noise of the locked magnetron of ?70 dBc at a 40-kHz offset was improved in comparison with an unlocked magnetron. The results show that an injection-locked magnetron with an external oscillator has great potential for obtaining a high power output.
关键词： frequency locking,injection-locked magnetron,Equivalent circuit model of magnetron
更新于2025-09-19 17:13:59