- 标题
- 摘要
- 关键词
- 实验方案
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Evaluation of the Impact of MZM Frequency Response on BER Performance of PAM-4 Modulated WDM-PON
摘要： Continuous growth of data tra?c in optical access networks is driving the increase of utilized data rates even up to 25 Gbit/s per wavelength. While due to utilization of signals with large electrical bandwidth, requirements on the bandwidth of electrical and electro-optical components increase signi?cantly. Addressing that, the feasibility of application of the minimal transmitter and receiver bandwidth has received considerable attention. In this research, via numerical simulation in VPI Photonics Design Suite software we evaluate the impact of the shape of MZM frequency response based on amplitude frequency response (S21) from commercial MZM speci?cation. Moreover, addressing the requirements on numerical simulation models that ensure simulation of MZM frequency response curve for prediction of the overall system performance, we have also evaluated several analytical frequency responses (corresponding to the responses of 1 and 4-pole, Bessel and Gaussian ?lters) with di?erent 3-dB bandwidth values. Based on the obtained results, we propose the approach for the simulation of MZM frequency response that is the most relevant for our utilized PAM-4 modulated WDM-PON system with 25 Gbit/s bitrate per channel.
关键词： MZM frequency response,PAM-4 modulated WDM-PON,numerical simulation,VPI Photonics Design Suite,BER performance
更新于2025-09-23 15:19:57
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Intelligent Spectroscopy System Used for Physicochemical Variables Estimation in Sugar Cane Soils
摘要： The current condition of soils is a major area of interest due to the lack of certainty in their physicochemical properties, which can guarantee the quality and the production of a specific crop. Additionally, methodologies to improve land management must be implemented in order to address the consequences of many environmental issues. To date, many techniques have been implemented to improve the accuracy—and more recently the speed—of analysis, in order to obtain results while in the field. Among those, Near Infrared (NIR) spectroscopy has been widely used to achieve the objectives mentioned above. Nevertheless, it requires particular knowledge, and the cost might be high for farmers who own the fields and crops. Thus, the present work uses a system that implements capacitance spectroscopy plus artificial intelligence algorithms to estimate the physicochemical variables of soil used to grow sugar cane. The device uses the frequency response of the soil to determine its magnitude and phase values, which are used by artificial intelligence algorithms that are capable of estimating the soil properties. The obtained results show errors below 8% in the estimation of the variables compared to the analysis results of the soil in laboratories. Additionally, it is a portable system, with low cost, that is easy to use and could be implemented to test other types of soils after evaluating the necessary algorithms or proposing alternatives to restore soil properties.
关键词： FPGA-based,psychochemical prediction,frequency response of soil
更新于2025-09-19 17:15:36
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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) - The Journey from Manipulating Single Quantum Systems to Quantum Information Processing
摘要： The quality factor of a resonator represents the decay of vibrational energy over time, and is directly related to the frequency response and other key parameters that determine performance of inertial sensors and oscillators. Accurate prediction of the quality factor is essential for designing high-performance microelectromechanical (MEMS) devices. Several to the quality factor. Due to computational complexity, highly simplified models for the dominant dissipation mechanism, such as Zener’s model for thermoelastic dissipation (TED), are often the intuition provided by these models employed. However, is inadequate to predict the quality factor of more complex designs and can be highly misleading. In this paper, we construct complete, quantitative, and predictive models with finite-element methods for the intrinsic energy dissipation mechanisms in MEMS resonators using full anisotropic representation of crystalline silicon and the temperature dependence of all parameters. We find that TED is often a more significant source of damping than has been assumed, because of the previously neglected role of crystalline anisotropy and small geometric features, such as etch release holes—all of which can now be included in practical models. We show that these models, along with simpler scaling models for extrinsic dissipation mechanisms, explain measurements of quality factor in diverse sets of MEMS resonators with unprecedented accuracy.
关键词： internal friction,frequency response,micromechanical resonators,microelectromechanical devices,thermal-mechanical coupling,thermoelastic dissipation,geometry,resonance,systems,Capacitive sensors,damping,energy dissipation,frequency-domain analysis
更新于2025-09-19 17:13:59
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Electro-thermal Model of Approximated Organic Tissue for Investigation of Harmful Electrosurgical Impacts
摘要： The quality factor of a resonator represents the decay of vibrational energy over time, and is directly related to the frequency response and other key parameters that determine performance of inertial sensors and oscillators. Accurate prediction of the quality factor is essential for designing high-performance microelectromechanical (MEMS) devices. Several to the quality factor. Due to computational complexity, highly simplified models for the dominant dissipation mechanism, such as Zener’s model for thermoelastic dissipation (TED), are often the intuition provided by these models employed. However, is inadequate to predict the quality factor of more complex designs and can be highly misleading. In this paper, we construct complete, quantitative, and predictive models with finite-element methods for the intrinsic energy dissipation mechanisms in MEMS resonators using full anisotropic representation of crystalline silicon and the temperature dependence of all parameters. We find that TED is often a more significant source of damping than has been assumed, because of the previously neglected role of crystalline anisotropy and small geometric features, such as etch release holes—all of which can now be included in practical models. We show that these models, along with simpler scaling models for extrinsic dissipation mechanisms, explain measurements of quality factor in diverse sets of MEMS resonators with unprecedented accuracy.
关键词： micromechanical resonators,energy dissipation,Capacitive sensors,frequency-domain analysis,damping,frequency response,geometry,thermal-mechanical coupling,resonance,thermoelastic dissipation,internal friction,microelectromechanical devices,systems
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Applying Lessons from Leaf Anatomy and Array Structure to the Development of Solar Cells Exhibiting Enhanced Electricity Production
摘要： Magnetically coupled impedance-source (MCIS) networks are recently introduced impedance networks intended for various high-boost applications. It employs coupled magnetic in the circuit to achieve higher voltage gain. Various MCIS networks have been proposed in the literature for myriad applications; however, due to effective role of system modeling in the closed-loop controller design, this paper is allocated to small-signal modeling and analysis of MCIS converters. The modeling is performed by means of the circuit averaging and averaged switch technique. A generalized small-signal derivation is demonstrated for pulse width modulation (PWM) MCIS converters and it is shown that the derived transfer functions can simply be applied to Y-source, Γ-source, and T-source impedance networks. Various transfer functions for capacitor voltage, output voltage, magnetizing current, input and output impedance are derived and have been validated through frequency and dynamic responses of computer simulation results. In addition, a comprehensive analysis has been done for all mentioned PWM MCIS converters regarding their circuit parameters. Furthermore, the effect of considering the equivalent series resistances of capacitor and inductor on the stability margin of MCIS converters is revealed in this paper. Finally, in order to validate the derived transfer functions and to consolidate the perfumed analysis, experimental results are presented for all mentioned MCIS converters.
关键词： frequency response,Circuit averaging technique,magnetically coupled impedance-source (MCIS) network,dynamic response,nonminimum phase (NMP) zero,small-signal modeling
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Theoretical and experimental study on optical fiber microseismic accelerometer based on cantilever beam structure
摘要： According to the characteristics of underground environment and microseismic signal in coal mine, a kind of optical fiber microseismic accelerometer based on cantilever beam structure is put forward in this paper, and its mechanical model is established, its sensitivity is analyzed, and tested by B&K shaking table test system. The experimental results show that the frequency response range of the sensor is 10Hz-100Hz, which meets the requirements of microseismic test.
关键词： FBG,accelerometer,microseismic,cantilever beam,frequency response
更新于2025-09-16 10:30:52
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Dispersion-enhanced tunability of the laser-frequency response to the cavity-length change
摘要： We report on the controllable response of the lasing frequency to the cavity round-trip path change. This is achieved by modifying the dispersion of the intracavity medium in the four-wave mixing regime in Rb. We can either increase the response by at least a factor of 2.7 or drastically reduce it. The former regime is useful for sensitive measurements tracking the cavity round-trip length and the latter regime is useful for precision metrology.
关键词： dispersion,laser-frequency response,cavity-length change,four-wave mixing,Rb
更新于2025-09-16 10:30:52
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Solution-processed QD-LEDs in visible range: Modulation bandwidth enhancement
摘要： Light-emitting diodes based on quantum dots (QD-LEDs) have attracted much attention not only due to their usage in lighting and display applications but also as the light sources in visible light communication (VLC). One of the most important parameters of a QD-LED as a light source is the improvement of modulation bandwidth in order to increase the data transfer rate. Here, three sets of QD-LEDs are presented for which some parameters such as frequency response are investigated, once for the devices with similar structure but different homogeneities and then for those with minor changes in the structure. It was found that by changing the homogeneity of QDs in the same structure based on CdSe/ZnS and using the ZnO shell instead of ZnS, the modulation bandwidth varied between 2 and 8 MHz. Furthermore, for the structure based on CdSe/ZnS, the modulation bandwidth of 8 MHz is achieved which is fairly a wide bandwidth for a QD-LED. The idea of manipulation in the structure of nanomaterials can be an important step toward increasing the modulation bandwidth. According to calculated results, the carrier density in different layers is calculated and then the recombination current-voltage characteristics are compared with the experimental results, indicating high conformity.
关键词： Light emitting diode,Frequency response,CdSe/ZnS,Quantum dots,Modulation bandwidth
更新于2025-09-16 10:30:52
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Equivalent Circuit of Quantum-Dot LED and Acquisition of Carrier Lifetime in Active Layer
摘要： We propose an equivalent circuit for a quantum-dot LED (QLED), where the resistances and the capacitances are expressed in terms of the physical parameters of the QLED. The validity of the equivalent circuit is verified by measurement results. From the measured frequency response of the QLED and the calculated frequency response of the equivalent circuit, we are able to deduce the carrier lifetime in the active layer of the QLED. The availability of the equivalent circuit can facilitate the analysis of the electrical characteristics of QLEDs.
关键词： Quantum-dot light-emitting diode,frequency response,carrier lifetime,equivalent circuit
更新于2025-09-12 10:27:22
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Optimization of the frequency response of a novel GaAs plasmonic terahertz detector
摘要： Previously there was reported a new type of high-speed plasmonic THz detector that can operate at room temperature. As an extension of that work, the sensitivity of the detector was investigated over a wide range of sub-THz frequencies. The measured frequency response is not purely monotonic but exhibits oscillatory behaviour with a number of maxima and minima. Our study reveals that such frequency dependence is caused by the interference of electromagnetic waves inside the detector substrate, as the frequencies of these extrema are found to be governed by the substrate thickness. We demonstrate that sensitivity of this type of detector can be optimized for the desired operating frequency within 0.06–0.7 THz spectrum by adjusting the substrate thickness. We also show that a monotonic frequency response with eliminated minima can be achieved by mounting the detector on a specially designed silicon lens.
关键词： Detection,Frequency response,Terahertz
更新于2025-09-12 10:27:22