检索结果-南通市图书馆

A low power automatic gain control loop for a receiver

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第9期31卷 108-112页

作者：李国锋耿志卿吴南健 state key laboratory for super lattices and microstructures Institute of SemiconductorsChinese Academy of Sciences

This paper proposes a new structure to lower the power consumption of a variable gain amplifier（VGA） and keep the linearity of the VGA *** structure is used in a high rate amplitude-shift keying（ASK） based *** includes an automatic gain control（AGC） loop and ASK *** AGC mainly consists of sixstage *** IF-stage is realized in 0.18μm CMOS *** measurement results show that the power consumption of the whole system is very *** system consumes 730μA while operating at 1.8 *** minimum ASK signal the system could detect is 0.7 mV（peak to peak amplitude）.

关键词： low power linearity variable gain amplifier automatic gain control loop amplitude-shift keying

A low power flexible PGA for software defined radio systems

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2012年第5期33卷 120-125页

作者：李国锋吴南健 state key laboratory of super lattices and microstructures Institute of SemiconductorsChinese Academy of Sciences

This paper proposes a new low power structure to improve the trade-off between the bandwidth and the power consumption of a programmable gain amplifier（PGA）.The PGA consists of three-stage amplifiers, which includes a variable gain amplifier and DC offset cancellation *** cutoff frequency of the DC offset cancellation circuits can be changed from 4 to 80 *** chip was fabricated in 0.13μm CMOS technology. Measurement results showed that the gain of the PGA can be programmed from -5 to 60 *** the gain setting of 60 dB,the bandwidth can be tuned from 1 to 10 MHz,while the power consumption can be programmed from 850μA to 3.2 mA at a supply voltage of 1.2 *** in-band OIP3 result is at 14 dBm.

关键词： low power DC offset programmable gain amplifier software defined radio

Fabrication of VO_2 thin film by rapid thermal annealing in oxygen atmosphere and its metal–insulator phase transition properties

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第7期23卷 617-621页

作者：梁继然吴劢君胡明刘剑朱乃伟夏晓旭陈弘达 School of Electronic Information and Engineering Tianjin University state key laboratory for super lattices and microstructures Institute of Semiconductors Chinese Academy of Sciences state key laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences

Vanadium dioxide thin films have been fabricated through sputtering vanadium thin films and rapid thermal annealing in oxygen. The microstructure and the metal-insulator transition properties of the vanadium dioxide thin films were inves- tigated by X-ray diffraction, X-ray photoelectron spectroscopy, and a spectrometer. It is found that the preferred orientation of the vanadium dioxide changes from （111） to （011 ） with increasing thickness of the vanadium thin film after rapid thermal annealing. The vanadium dioxide thin films exhibit an obvious metal-insulator transition with increasing temperature, and the phase transition temperature decreases as the film thickness increases. The transition shows hysteretic behaviors, and the hysteresis width decreases as the film thickness increases due to the higher concentration carriers resulted from the uncompleted lattice. The fabrication of vanadium dioxide thin films with higher concentration carriers will facilitate the nature study of the metal-insulator transition.

关键词： vanadium dioxide metal-insulator transition rapid thermal annealing hysteresis

An ultra-low-power area-efficient non-volatile memory in a 0.18μm single-poly CMOS process for passive RFID tags

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2013年第8期34卷 94-98页

作者：贾晓云冯鹏张胜广吴南健赵柏秦刘肃 state key laboratory for super lattices and microstructures Institute of SemiconductorsChinese Academy of Sciences Institute of Microelectronics School of Physical Science and TechnologyLanzhou University Institute of Microelectronics School of Physical Science and TechnologyLanzhou UniversityLanzhou 730000China

This paper presents an ultra-low-power area-efficient non-volatile memory（NVM） in a 0.18μm singlepoly standard CMOS process for passive radio frequency identification（RFID） *** the memory cell,a novel low-power operation method is proposed to realize bi-directional Fowler-Nordheim tunneling during write operation. Furthermore,the cell is designed with PMOS transistors and coupling capacitors to minimize its *** order to improve its reliability,the cell consists of double floating gates to store the data,and the 1 kbit NVM was implemented in a 0.18μm single-poly standard CMOS *** area of the memory cell and 1 kbit memory array is 96μm^2 and 0.12 mm^2,*** measured results indicate that the program/erase voltage ranges from 5 to 6 *** power consumption of the read/write operation is 0.19μW/0.69μW at a read/write rate of （268 kb/s）/（3.0 kb/s）.

关键词： non-volatile memory ultra-low-power area-efficient CMOS RFID

Infrared transition properties of vanadium dioxide thin films across semiconductor-metal transition

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2011年第3期30卷 247-251页

作者： LIANG Jiran HU Ming KAN Qiang LIANG Xiuqin WANG Xiaodong LI Guike CHEN Hongda School of Electronic and Information Technology Tianjin University Tianjin 300072 China state key laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Engineering Research Center for Semiconductor Integrated Technology Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China state key laboratory for super lattices and microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction （XRD）, atom force microscopy （AFM）, and Fourier transform infrared spectrum （FTIR） were employed to measure the crystalline structure, surface morphology, and infrared optical transmittance. The phase transition properties were characterized by transmittance. The results show that the annealed vanadium oxide thin film is composed of monoclinic VO2, with preferred orientation of （011）. The maximum of transmittance change is beyond 65% as the temperature increases from 20 to 80 C. The reversible changes in optical transmittance against temperature were observed. The change rate of transmittance at short wavelength is higher than that at long wavelength at the same temperature across semiconductor-metal phase transition. This phenomenon was discussed using diffraction effect.

关键词： vanadium dioxide infrared transition diffraction effect dual ion beam sputtering annealing

Localization and Steering of Light in One-Dimensional Parity-Time Symmetric Photonic lattices

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2019年第1期36卷 14-18页

作者： Xing Wei ZhenDa Xie Yan-Xiao Gong Xinjie Lv Gang Zhao ShiNing Zhu National laboratory of Solid state microstructures and School of Physics Nanjing University College of Electronic Science and Engineering National Laboratory of Solid State MicrostructuresNanjing University College of Engineering and Applied Sciences National Laboratory of Solid State MicrostructuresNanjing University

We theoretically study the propagation dynamics of input light in one-dimensional mixed linear-nonlinear photonic lattices with a complex parity-time symmetric potential. Numerical computation shows simultaneous localization and steering of the optical beam due to the asymmetric scatter and interplay between Kerr-type nonlinearity and PT symmetry. This may provide a feasible measure for manipulation light in optical communications, integrated optics and so on.

关键词： Localization Steering One-Dimensional Parity-Time Symmetric Photonic lattices

High-pressure phases of Weyl semimetals NbP, NbAs, TaP,and TaAs

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2018年第3期61卷 47-55页

作者： ZhaoPeng Guo PengChao Lu Tong Chen JueFei Wu Jian Sun DingYu Xing National laboratory of Solid state microstructures School of Physics and Collaborative Innovation Center of Advanced MicrostructuresNanjing University

In this study, we used the crystal structure search method and first-principles calculations to systematically explore the highpressure phase diagrams of the TaAs family （NbP, NbAs, TaP, and TaAs）. Our calculation results show that NbAs and TaAs have similar phase diagrams, the same structural phase transition sequence I41md→Pδm2→}P21/c→Pm3m, and slightly different transition pressures. The phase transition sequence of NbP and TaP differs somewhat from that of NbAs and TaAs, in which new structures emerge, such as the Cmcm structure in NbP and the Pmmn structure in TaP. Interestingly, we found that in the electronic structure of the high-pressure phase Pδm2-NbAs, there are coexisting Weyl points and triple degenerate points, similar to those found in high-pressure Pδm2-TaAs.

关键词： high pressure phase transition crystal structure prediction topological materials Dirac/Weyl/node-line semimetals Fermi arc

Electric-Field-Treated Ni/Co_(3)O_(4) Film as High-Performance Bifunctional Electrocatalysts for Efficient Overall Water Splitting

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第9期14卷 160-173页

作者： Junming Li Jun Li Jun Ren Hong Hong Dongxue Liu Lizhe Liu Dunhui Wang National laboratory of Solid state microstructures Collaborative Innovation Center of Advanced MicrostructuresJiangsu Provincial Key Laboratory for NanotechnologySchool of PhysicsNanjing UniversityNanjing 210093People’s Republic of China Hangzhou Dianzi University Hangzhou 310018People’s Republic of China

Rational design of bifunctional electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)with excellent activity and stability is of great significance,since overall water splitting is a promising technology for sustainable conversion of clean ***,most electrocatalysts do not simultaneously possess optimal HER/OER activities and their electrical conductivities are intrinsically low,which limit the development of overall water *** this paper,a strategy of electric field treatment is proposed and applied to Ni/Co_(3)O_(4) film to develop a novel bifunctional *** treated by electric field,the conductive channels consisting of oxygen vacancies are formed in the Co_(3)O_(4) film,which remarkably reduces the resistance of the system by almost 2×10^(4) ***,the surface Ni metal electrode is partially oxidized to nickel oxide,which enhances the catalytic *** electric-field-treated Ni/Co_(3)O_(4) material exhibits super outstanding performance of HER,OER,and overall water splitting,and the catalytic activity is significantly superior to the state-of-the-art noble metal catalysts(Pt/C,RuO_(2),and RuO_(2)‖Pt/C couple).This work provides an effective and feasible method for the development of novel and efficient bifunctional electrocatalyst,which is also promising for wide use in the field of catalysis.

关键词： Bifunctional electrocatalyst Overall water splitting Co_(3)O_(4)film Oxygen vacancies Electric field

Lieb lattices Formed by Real Atoms on Ag(111)and Their Lattice Constant-Dependent Electronic Properties

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2022年第5期39卷 71-75页

作者： Xiaoxia Li Qili Li Tongzhou Ji Ruige Yan Wenlin Fan Bingfeng Miao Liang Sun Gong Chen Weiyi Zhang Haifeng Ding National laboratory of Solid state microstructures and Department of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced microstructures Nanjing 210093China

Scanning tunneling microscopy is a powerful tool to build artificial atomic structures that do not exist in nature but possess exotic *** this study,we constructed Lieb lattices with different lattice constants by real atoms,i.e.,Fe atoms on Ag(111),and probed their electronic *** obtain a surprising long-range effective electron wavefunction overlap between Fe adatoms as it exhibits a 1/r;dependence with the interatomic distance r instead of the theoretically predicted exponential *** control experiments,tight-binding modeling,and Green’s function calculations,we attribute the observed long-range overlap to being enabled by the surface *** findings enrich the understanding of the electron wavefunction overlap and provide a convenient platform to design and explore artificial structures and future devices with real atoms.

关键词： properties overlap exponential