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- 摘要
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- 实验方案
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai, China (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - Dynamic Metasurface for Synthetic Apeture Radar Imaging
摘要： In this paper, a PIN dioded loaded programmable metasurface element and dynamic apeture has been proposed. The programmable element-a complementary electric LC (cELC) resonator is patterned into the microstrip transmission line. Two PIN diodes are integrated across the capacitive gap of the cELC element, The digital states of each coding element can be controlled in real time by changing the states of PIN diodes . The proposed dynamic aperture has potential applications in dynamic beamforming, electromagnetic imaging, and security check.
关键词： PIN diode,cELC,dynamic aperture
更新于2025-09-23 15:23:52
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Measurement and Determination of the Unified Glare Rating of Indoor Lighting Systems
摘要： The paper presents a results of software calculation and experimental measurement determination of unified glare rating (UGR) for two teacher rooms in an educational building. Three-dimensional computer modeling and multivariate UGR software calculation with light-emitting diode luminaires having different lighting distributions and taking into account the actual position and the line of sight of the observer are performed. A methodology for experimental measurement and determination of UGR has been proposed and demonstrated for the same two rooms. The results are presented in tabular and graphical form. A comparative analysis of the results obtained from the software calculations and the experimental determination of UGR is carried out. Conclusions have been made about the influence on the accuracy of the URG values obtained of the light distribution type of the luminaires, the location and orientation of the line of sight of the observer, and the choice of the background luminance surface.
关键词： indoor lighting,Unified Glare Rating,unified glare rating measurement,light-emitting diode luminaire
更新于2025-09-23 15:23:52
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Direct Imaging of Surface Plasmon-Driven Hot Electron Flux on the Au Nanoprism/TiO <sub/>2</sub>
摘要： Direct measurement of hot electron flux from a plasmonic Schottky nanodiode is important for obtaining fundamental insights explaining the mechanism for electronic excitation on a surface. Here, we report the measurement of photo-induced hot electrons on a triangular Au nanoprism on TiO2 under incident light with photoconductive atomic force microscopy (pc-AFM), which is direct proof of the intrinsic relation between hot electrons and localized surface plasmon resonance. We find that the local photocurrent measured on the boundary of the Au nanoprism is higher than that inside the Au nanoprism, indicating that field confinement at the boundary of the Au nanoprism acts as a hot spot, leading to the enhancement of hot electron flow at the boundary. Under incident illumination with a wavelength near the absorption peak (645 nm) of a single Au nanoprism, localized surface plasmon resonance resulted in the generation of a higher photo-induced hot electron flow for the Au nanoprism/TiO2, compared with that at a wavelength of 532 nm. We show that the application of a reverse bias results in a higher photocurrent for the Au nanoprism/TiO2, which is associated with a lowering of the Schottky barrier height caused by the image force. These nanoscale measurements of hot electron flux with pc-AFM indicate efficient photon energy transfer mediated by surface plasmons in hot electron-based energy conversion.
关键词： hot electron,Photoconductive atomic force microscopy,localized surface plasmon resonance,Schottky diode,field confinement,Au nanoprism
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Comparison Study of Surge Current Capability of Body Diode of SiC MOSFET and SiC Schottky Diode
摘要： The superior performance of the SiC MOSFETs operating in synchronous mode converter without external antiparallel SiC Schottky diodes have been demonstrated recently. However, there are few studies of the surge current capability of the SiC MOSFET's body diode, leading severe concern for its ruggedness in practical power converter applications. The purpose of this paper is to experimentally compare the non-repetitive surge current capability of the SiC MOSFET's intrinsic body diode and SiC Schottky diode, and analyze the physical mechanisms of their degradation after surge current stress. Their surge current capability and electrical characteristics before and after surge current stress are measured and analyzed. Experimental study shows that the non-repetitive peak surge current of the SiC MOSFET’s body diode is slightly larger than that of the SiC Schottky diodes. The degradation of the SiC Schottky diode after surge current stress is accompanied with the increase of drain leakage current, while the degradation of the SiC MOSFET after the body diode’s surge current stress is accompanied with the variation of the threshold voltage and input capacitance of the SiC MOSFET. The analysis shows that the degradation of the SiC MOSFET after the surge current stress may be correlated with the interface traps of SiC/SiO2 interface.
关键词： Body diode,SiC Schottky Diode,SiC MOSFET,Surge current
更新于2025-09-23 15:22:29
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High-gain optical injection locking amplifier in phase-coherent optical frequency transmission
摘要： Optical amplification, which is necessary for extending the distance of optical frequency transfer, has significant impact on the transmission performance. In this paper, we propose a high gain optical injection locking amplifier (OILA) with low phase noise based on optical injection phase-locked loop for the phase-coherent optical frequency transmission. The high gain OILA can provide more than 75 dB gain and ensure that the input carrier frequency fractional stability can reach 8.2 × 10-20 at an averaging time of over 100 s. We then transfer a commercial narrow-linewidth laser over 220 km fiber link with only one amplification step placed at the remote end. After eliminating the noise induced in fiber link, the fractional frequency instability of transferred frequency can reach 9.0 × 10?16 at 1 s and 7.1 × 10?20 at 20000 s.
关键词： Laser injection-locked,Optical standards and testing.,Metrology,Diode lasers
更新于2025-09-23 15:22:29
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Compact Real-Time Inter-Frame Histogram Builder for 15Bits High-Speed ToF-Imagers based on Single-Photon Detection
摘要： Time-of-flight image sensors based on single-photon detection, i.e. SPADs, require some filtering of pixel readings. Accurate depth measurements are only possible if the jitter of the detector is mitigated. Moreover, the time stamp needs to be effectively separated from uncorrelated noise such as dark counts and background illumination. A powerful tool for this is building a histogram of a number of pixel readings. Future generation of ToF imagers are seeking to increase spatial and temporal resolution along with the dynamic range and frame rate. Under these circumstances, storing the complete histogram for every pixel becomes practically impossible. Considering that most of the information contained by the histogram represents noise, we propose a highly efficient method to store just the relevant data required for ToF computation. This method makes use of the shifted inter-frame histogram (SifH). It requires a memory as low as 128 times smaller than storing the complete histogram if the pixel values are coded on up to 15 bits. Moreover, a fixed 28 words memory is enough to process histograms containing up to 215 bins. In exchange, the overall frame rate only decreases to one half. The hardware implementation of this algorithm is presented. Its remarkable robustness for a low SNR of the ToF estimation is demonstrated by Matlab simulations and FPGA implementation using input data from a SPAD camera prototype.
关键词： shifted inter-frame histogram (SifH),single-photon avalanche-diode (SPAD),real-time time-of-flight (ToF) estimation,ToF image sensor
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Students' Conference on Electrical, Electronics and Computer Science (SCEECS) - Bhopal (2018.2.24-2018.2.25)] 2018 IEEE International Students' Conference on Electrical, Electronics and Computer Science (SCEECS) - Solar Power Based Three-Level Neutral Clamped Inverter Fed DTFC-SVM of an IM Drive
摘要： This paper presents a solar power based three-level neutral clamped inverter (3LNCI) fed induction motor drive (IMD) with space vector modulation based direct torque and flux control (DTFC-SVM) for the water pumping applications. Due to the robustness and the flexible operating characteristics, induction motor is most suitable for water pump system. A DC/DC boost converter along with perturb and observe method of maximum power point tracking (MPPT) control technique is employed to draw sophisticated power from the solar photovoltaic (PV) array. The DTFC-SVM of an IMD using 3LNCI is proposed for improving performance and reducing the ripple contents of torque, flux and stator currents. The proposed method is simulated in MATLAB/SIMULINK environment and simulated results are presented under various operating conditions.
关键词： photovoltaic array,space vector modulation,induction motor drive,three-level diode clamped inverter,Direct torque and flux control
更新于2025-09-23 15:22:29
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Reverse annealing studies of irradiated silicon by use of current–voltage measurements
摘要： The annealing behaviour of irradiated silicon p-i-n diodes has been investigated by use of I–V measurements. The radiation-induced damage is achieved by the use of 1 MeV neutrons. The results have been analysed and a striking feature is easily noticeable where defects that do not anneal out alter their activity and behave more as generation centres. This means that they are situated in the upper half of the band gap where they act to increase the carrier density and the measured current. The increase in current starts to occur at around 100 days and a change in trap activity at around 180 days after irradiation. The device behaviour, however, remains ohmic throughout indicating that a defect level that is responsible for relaxation behaviour is stable. This study would assist in demonstrating stability of silicon radiation detectors during their operational time.
关键词： Diode,Current,Radiation,Semiconductor,Silicon,Annealing
更新于2025-09-23 15:22:29
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[IEEE 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Bangkok, Thailand (2018.9.26-2018.9.29)] 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Design of Voltage Reference Comparator Circuit for Receiver Circuit in VLC System
摘要： Visible light communication (VLC) system is a wireless communication from light of the light emitting diode (LED). In this work, we design the voltage reference comparator circuit method for the receiver circuit with data communication via white LED. In this experiment, we evaluate the VLC system of the transmitter circuit and receiver circuit by using bits data communication with the distance 50 to 100 cm. We measure the frequency of the white LED signal detection between the transmitter circuit and the receiver circuit, which the frequency uses about 9.615 kHz. This comparator circuit method can be used to refer the voltage signals of the receiver circuit in VLC system.
关键词： Photodiode,Amplify circuit,Light emitting diode,Visible light communication,Comparator circuit
更新于2025-09-23 15:22:29
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High Speed Wireless Internet Using LiFi
摘要： The internet has become a basic necessity, so with the advancement in technology, people are demanding something faster than WI-FI. Since light is the only medium that can travel fastest than any other source of data transmission else so if we use this medium for internet, it will be the best utilization of medium with a higher data transmission rate. This technology was implemented over and came out with concept of LI-FI Technology. Li-Fi in known for Light-Fidelity, Li-Fi uses an idea of visible light communication (VLC) technology that uses light as a medium to convey fast high-speed communication in a manner like Wi-Fi. Since visible light is present everywhere, the main idea of our review paper is how LI-FI technology can help in security, speed and reliability of internet and even can change our life style. This innovation is actualized utilizing white LED bulbs matched with the Downlink transmitter that can give a higher information transmission rate up to 10Gbps. The main prospective of this paper demonstrates the forthcoming routine of Li-Fi technology innovation and its highlights to expand the execution of information transmission and different applications where Li-Fi has been put to utilize.
关键词： Data utilization,Visible Light communication,Wi-Fi,server,Light-emitting diode (LED),Light-Fidelity (Li-Fi),Video LAN Client (VLC)
更新于2025-09-23 15:22:29