- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A 200 Mb/s～3.2 Gb/s referenceless clock and data recovery circuit with bidirectional frequency detector
摘要： This paper presents a 200-Mb/s to 3.2-Gb/s half-rate referenceless clock and data recovery (CDR) circuit in 180 nm CMOS process. A bidirectional frequency detector (FD) is proposed to eliminate the harmonic locking and reduce the frequency acquisition time. A frequency band selector for wide-range the voltage-control oscillator (VCO) is also presented to select an exact frequency band of the VCO. The simulation shows the CDR achieves 11-ps peak-to-peak jitter at 3 Gb/s and the frequency acquisition time of 11.8 μs.
关键词： wide-band VCO,bidirectional frequency detector,referenceless,clock and data recovery
更新于2025-09-23 15:23:52
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Effect of Hydration Procedure of Fumed Silica Precursor on the Formation of Luminescent Carbon Centers in SiO <sub/>2</sub> :C Nanocomposites
摘要： The effect of hydration procedure of fumed silica precursor on photoluminescent properties of carbonized silica (SiO2:C) nanocomposite after chemo/thermal treatments is studied. Main structural effect is the formation of chemical bonding of phenyl groups to silica surface via multiple C─Si─O bonding bridges. Synthesized samples demonstrate very broad photoluminescence (PL) bands in near ultraviolet and visible ranges with maximum intensity dependent on temperature of thermal annealing. Two main trends in luminescence properties are: 1) hydration-induced blue shift of PL in comparison with PL of unhydrated series; 2) red shift of PL bands with increasing synthesis temperature regardless hydration procedure. Temperature dependent evolution of light emission bands is discussed in terms of surface carbon nanoclusters formation and aggregation processes. It is assumed that blue shift of PL bands in the hydrated series is associated with the decreased surface mobility of carbon atoms and clusters as a result of increased chemical bonding with silica surface that slows down carbon thermally stimulated clusterization/aggregation processes.
关键词： carbonized nanocomposite material,carbonized fumed silica,phenyltrimethoxysilane,wide-band visible photoluminescence,carbon clusters
更新于2025-09-23 15:23:52
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Improved reflection technique for the permittivity measurement of ferrites using slotted coaxial samples
摘要： This paper presents the effect of magnetic permeability on the permittivity measurement using coaxial line reflection technique. It discusses in detail about the design aspects, analysis and simulation of the slotted co-axial sample and fixture for dielectric characterization of the ferrites and garnets possessing both dielectric and magnetic properties. This technique makes use of improved coaxial fixture and APC 07 compatible slotted coaxial sample geometry to measure the complex permittivity of the ferrite material. Permittivity is calculated from the impedance of sample loaded fixture, which is independent of magnetic permeability, because of air slot cut in the coaxial hollow cylindrical sample along the length. Characterization data of dielectrics and ferrites is used in design of ferrite circulators, and pulse magnets for particle accelerator applications. This is also used in many other RF applications including design of dielectric resonator for spin wave line width measurement of ferrites. Design work is aimed at accurate measurement of complex permittivity; using reflection measurement in coaxial fixture over a wide frequency range of 20 kHz to 1 GHz. Reflection measurement technique is further explored for accurate measurement of complex permittivity.
关键词： Complex permittivity,Network analyzer,Coaxial open ended fixture,Wide band measurement technique
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) - Current-Fed Quasi Z-Source Inverter Based PV Distributed Generation Controller
摘要： Recently, the renewable photovoltaic distributed generation (PV-DG) enjoys a rapid growth globally due to the advancement in solar systems and power electronics technologies. However, the intermittent nature of solar radiation and performance of the attached power converters, inevitably poses some challenges to the power grids integrated large-scale solar-farms (SF). These challenges include frequency oscillations, voltage variation and power quality issues. To overcome these problems, this study proposes a Current-Fed quasi Z-source Inverter (CF-qZSI) as an alternative converter for distribution generation controllers to facilitate the integration of a PV energy source into a weak power system. The detailed model of the CF-qZSI-based distribution controller (CqZDC) and its control system are developed. The dynamic performance of the CqZDC device is evaluated to validate different objectives using an actual field data and RTDS simulation platform.
关键词： frequency stability,current source inverter,wide band gap devices,Accommodation of renewable energy resources,power quality improving,facilitating of distributed electricity generations
更新于2025-09-23 15:23:52
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Dual Band Antenna For Portable Consumer Devices
摘要： The article proposes the design of a circular shaped patch antenna with a circular slot at its centre and a defected ground plane. The antenna operates in two distinct frequency bands, 2.3 GHz to 5.3 GHz and 7.2 GHz to 20 GHz and hence is suitable for applications in the S-band (2 GHz to 4 GHz), the X-band (8 GHz to 12 GHz) and the Ku-band (12 GHz to 20 GHz). The overall size of the antenna is 30mm*30mm*1.5mm which makes it suitable for applications in compact portable devices such as mobile phones, smart watches, bluetooth headsets, etc. Annealed copper is used as a conductor and the substrate is made up of FR4 which has an electrical permittivity of 4.3 and a loss tangent of 0.025. The simulated re?ection coef?cients, impedance curves and radiation patterns of the proposed antenna are described in detail in this paper.
关键词： antenna,impedance matching,simulations,ultra-wide band
更新于2025-09-23 15:23:52
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Miniaturization of Quad Port Helical Antenna for Wireless 5G Massive MIMO Application
摘要： A novel technique for the miniaturization of a quadrifilar helical antenna (QHA) with four independent ports, including for use in multiple-input multiple-output (MIMO) systems and other wireless communication systems. With the addition of one or more conductive components, a QHA may be achieved that has a more compact size, improved radiation patterns, sufficiently wide impedance bandwidth. Design is applied at 2.1-2.7 GHz.
关键词： 5G Wireless,quad antenna,Massive MIMO,wide band
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Design and Optimization of a Solar Power Conversion System for Space Applications
摘要： This manuscript details a design method for a 500kW solar power based microgrid system for space applications. The design method utilizes multi-objective optimization with the Genetic Algorithm considering four parameters that characterize solar power based microgrids (battery voltage, PV maximum power, PV maximum power point voltage, and number of panels per string). The final optimization metric is the ratio of daily average deliverable power to total system mass (W/kg) metric. The microgrid system is composed of a number of modular DC-DC micro-converters, of which four topologies (buck, boost, buck-boost and non-inverting buck-boost) are evaluated and compared. The non-inverting buck-boost converter is determined to be the best candidate, and the optimal system characteristics are provided and analyzed. The final system design achieves a specific power of 35.56W/kg, with optimized result of 743.7V battery voltage, 439.5W PV maximum power, 182.7V PV maximum voltage, and three panels per string. Based on the optimizations results, a prototype is designed, tested, and analyzed in terms of efficiency and low temperature reliability. The converter achieved a peak efficiency of 98.4%, a power density of 3.54W/cm3, a specific power of 3.76W/g, and operated for over 267 hours of 11-minute low temperature cycles from 0oC to -140oC.
关键词： wide band gap semiconductors,microgrids,non-inverting buck-boost,maximum power point trackers,space exploration,photovoltaic systems,design optimization,DC-DC power converters,system-level design,low temperature testing
更新于2025-09-23 15:23:52
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Regional Manufacturing Cost Structures and Supply Chain Considerations for SiC Power Electronics in Medium Voltage Motor Drives
摘要： With the growth in wide bandgap (WBG) semiconductors, specifically Silicon Carbide (SiC), the technology has matured enough to highlight a need to understand the drivers of manufacturing cost, regional manufacturing costs, and plant location decisions. Further, ongoing research and investment, necessitates analytical analysis to help inform development of wide bandgap technologies. The paper explores the anticipated device, module, and motor drive cost at volume manufacturing. It additionally outlines the current regional contributors to the supply chain and proposes how the base models can be used to evaluate the cost reduction potential of proposed research advances.
关键词： Wide bandgap,Supply chain,SiC,Wide-band gap,Wideband gap,Techno-economic,WBG,bottoms-up,Medium voltage,Motor drive,Wide band-gap,Analysis,Power electronics,Cost model
更新于2025-09-23 15:22:29
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Design of A Two-Dimensional “T” Shaped Metamaterial with Wideband, Low Loss
摘要： A novel two-dimensional (2D) metamaterial structure with center symmetric "T" shaped unit is designed, fabricated, and measured in this paper. The proposed metamaterial comprises of a 2 × 2 array of area 4.3 mm × 4.3 mm, etched on single side of FR4 substrate. The simulation and measurement show that the novel metamaterial has a double negative range frequency of 20.16–37.47 GHz with an absolute width of 17.31 GHz, relative width of 60.07%, small unit loss of 0.16 dB, and small size of 0.07 λ0 in 2D. Furthermore, the double negative region of the proposed metamaterial operates through K band and Ka band, it can be widely used in satellite communication and broadband digital transmission.
关键词： center symmetric "T" shaped,Two dimensions,low loss,wide band
更新于2025-09-23 15:22:29
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Remote Vital Sign Recognition through Machine Learning augmented UWB
摘要： This paper describes an experimental demonstration of machine learning (ML) techniques supplementing radar to distinguish and detect vital signs of users in a domestic environment. This work augments an intelligent location awareness system previously proposed by the authors. That research employed Ultra-Wide Band (UWB) radar complemented by supervised machine learning techniques to remotely identify a person’s room location via ?oor plan training and time stamp correlations. Here, the remote breathing and heartbeat signals are analyzed through Short Term Fourier Transformation (STFT) to determine the Micro-Doppler signature of those vital signs in different room locations. Then, Multi-Class Support Vector Machine (MC-SVM) is implemented to train the system to intelligently distinguish between vital signs during different activities. Statistical analysis of the experimental results supports the proposed algorithm. This work could be used to further understand, for example, how active older people are by engaging in typical domestic activities.
关键词： Short Term Fourier Transform (STFT),Breathing,Ultra-Wide Band (UWB),Multi-Class Support Vector Machine (MC-SVM),Heartbeat,Indoor Positioning System (IPS)
更新于2025-09-23 15:22:29