Thermally aware performance analysis of single-walled carbon nanotube bundle as VLSI interconnects

A comparative performance analysis in terms of delay, power dissipation, power delay product (PDP), and crosstalk noise between SWCNT bundle interconnects with resistance estimated using conventionally (temperature independent model), and thermally aware model is investigated. The results are also compared with those of currently used copper interconnects at 22 nm technology node. It is observed that, with rise in temperature from 300 to 500 K, SWCNT bundles have a lower delay than that of copper interconnect at different lengths from 100 to \(1000\,\upmu \hbox {m}\) whereas reverse is true for power dissipation. The SPICE simulation results further reveal that for temperature variations ranging from 300 to 500 K, compared to conventional metal (copper) conductors, crosstalk noise voltage levels (positive peaks) in capacitively coupled SWCNT bundle, at the far end of victim line, are significantly low. Moreover, a relative average improvement in delay, power, and PDP using a thermally aware model in comparison with a temperature independent model is about 22.44, 7.59 and 31.96 %, respectively, with length variations from 100 to \(1000\,\upmu \hbox {m}\), whereas for varied tube diameter is about 16.6, 5.6 and 19.72 %, respectively. The average relative improvement in the time duration reduction of victim output, for varied tube diameters, is about 21.7 % by using a thermally-aware model instead of a temperature-independent model of an SWCNT bundle resistance.     

Electromigration modeling for integrated circuit interconnectreliability analysis

A simple one-dimensional continuum model for electromigration transport has been fairly successful as a tool for understanding many empirical observations of electromigration phenomena in encapsulated interconnect lines on integrated circuits. In this paper, the development of the one-dimensional continuum electromigration model is reviewed, Comparisons are made with previous models, emphasizing the important similarities and differences,     

基于电路分块方法的超大规模集成电路测试技术

随着集成电路工艺和规模的飞速发展,使得VLSI测试变得日益困难,因此测试技术成为VLSI领域的一个重要研究课题。在分析VLSI测试的瓶颈问题基础上,介绍了几种电路分块算法,分析了分块算法对于VLSI测试的必要性。利用分块算法将原始电路划分为若干子块有利于采用不同BIST结构对子块进行测试,使得一定时间内电路翻转次数降低,而功耗也随之降低;通过比较并行BIST和扫描BIST的实验结果,发现并行BIST获得的系统故障覆盖率高于扫描BIST。     

负极添加碳纳米管的铅酸电池的性能

研究添加不同含量碳纳米管(CNT)和炭黑对铅酸电池负极板电化学性能的影响。添加适量的CNT会增大负极内孔体积,改善活性材料的颗粒形态,使颗粒大小更均匀,提高电化学反应动力学性能。添加0.5%CNT时,1 C首次放电容量提高3%,并将极板2 C、60 s放电循环的寿命延长接近一倍,电池在SBA S 0101测试中的循环寿命也超过普通电池一倍。     

异向旋转双机械口永磁电机磁路建模与场分析

为研究单电口输入、双机械口输出异向旋转永磁同步电机的设计方法,对定子铁心中异向旋转磁场的耦合问题进行分析.介绍该电机的特殊结构和运行原理,针对双场耦合的特点,通过引入可变径向磁阻,建立等效磁网络图并化简得到等效磁路模型,并推导了磁阻计算方法,最后利用有限元分析方法验证等效磁路模型的正确性.等效磁路模型将双耦合磁场引起的并联磁路和串联磁路共同问题简化为单一的并联磁路问题.研究结果表明:转子异向旋转对气隙磁场影响小于5%,可以降低定子轭部的平均磁密.因此,设计该类电机时可在满足机械强度的情况下,尽可能地减小定子铁心的厚度.     

A fast and stable Poisson-Schrödinger solver for the analysis of carbon nanotube transistors

When the coupled Schrödinger-Poisson system is solved iteratively with appropriate numerical damping, convergence problems are likely to occur. We show that these problems are due to inappropriate energy discretization for evaluating the carrier concentration. By using an adaptive method the self-consistent loop becomes stable, and most of the simulations converge in a few iterations. We applied this approach to investigate the behavior of carbon nanotube field effect transistors.     

Magic as a PC layout tool for small budget VLSI circuit design

The authors briefly describe the use of Magic, a CAD layout tool for VLSI circuits developed by the University of California, and how the program has been modified to operate on personal computers     

Issues in the modeling of carbon nanotube FETs: Structure, gate thickness, and azimuthal asymmetry

Factors affecting the modeling of practical carbon nanotube field-effect transistors are addressed, namely: non-coaxial geometries such as the double-planar gate, and the semi-cylindrical gate; the thickness of the gate metalization; the azimuthal variation of the potential and the current. The p-i-n device is used to illustrate the importance of these factors.     

碳纳米管场效应晶体管设计与应用

碳纳米管具有一些独特的电学性质,在纳米电子学有很好的应用前景。随着纳米技术的发展,新的工艺技术也随之产生。纳米器件的＂由下至上＂制作工艺,是在纳米技术和纳米材料的基础之上发展起来的,在新工艺基础之上,可以利用纳米管、纳米线的性质制作成各种新的电子器件。由于碳纳米管可以和硅在电子电路中扮演同样的角色,随着基于碳纳米管的纳米电路研究的深入发展,电子学将在真正意义上从微电子时代进入纳电子时代。从分析碳纳米管分立场效应晶体管典型结构特点入手,分析阐述了碳纳米管构建的典型纳米逻辑电路结构特征及碳纳米管在柔性纳米集成电路方面的应用。     

Fault arcs effects in cable bundles for space applications invacuum

A multitude of `arc tracking' tests on cables for space applications has been performed to improve the basic understanding of the phenomena responsible for the fault arc behavior. The damage in a cable bundle develops in a complex system consisting of metallic conductors, insulation materials and arc plasma. Considering the degradation effects, vacuum as one of the applied test parameters, has turned out to be an important test environment. The investigations are based on a new test method, developed to assess arc tracking properties of cables for space applications. Tests were conducted with different insulation materials at cables with different AWG at 125 V dc and nominal currents. The tests were focused on the vacuum environment, using air only for the purpose of comparison. For some cable types, vacuum has turned out to be a worst-case environmental condition with respect to fault arc effects, such as the conductor burn-off, degradation of the insulation of adjacent cables and the extension of the fault arc. This paper presents these worst case experiments in detail     

碳纳米管在锂离子电池中的应用

简述碳纳米管(CNT)的结构和性能;分析CNT作为导电剂可提高电池容量、比能量及循环性能的特点,以及分散困难、引起电池自放电严重等缺点。综述CNT作为导电剂在锂离子电池中的应用。     

Fast adjustable spectrum sensing circuit for cognitive radio applications

A fast and adjustable spectrum sensing method is proposed using a phase frequency detector for cognitive radio applications. Using this method, spectral sensing can be done in a very short time by a low‐cost, low‐power circuit, compared with available implemented methods. Different aspects of sensing procedure in different situations are investigated including frequency sweep time and system errors. Accurate operation of this method is verified through simulations, and comparison with other methods shows faster sweep rates. Copyright © 2013 John Wiley & Sons, Ltd.     

Emerging SiGe HBT reliability issues for mixed-signal circuit applications

We review the emerging reliability issues associated with high-performance SiGe HBT technologies which are being increasingly deployed in a wide variety of mixed-signal circuit applications. For the purposes of this work, we define the concept of device "reliability" to be broader than its standard usage in the industry, to include all possible transistor degradation mechanisms, for all possible mixed-signal circuit designs, in any of the various intended mixed-signal applications. For instance, in addition to classical device reliability mechanisms associated with reverse emitter-base and high forward current density stress, new reliability issues for SiGe HBTs, including impact-ionization induced "mixed-mode" stress, scaling-induced breakdown voltage compression and operating point instabilities, geometrical scaling-induced low-frequency noise variations, and the impact of ionizing radiation on device and circuit reliability, are also addressed.     

Equivalent circuit model for electric double layer capacitors and its applications

For a better understanding and detailed analysis of the electric behavior of EDLCs, we present one dynamic equivalent circuit model and two static ones, each of which consists of a resistance and a capacitance varying with voltage. A dynamic model based on the differential capacity is used to simulate the discharging curves. Also, two static models based on the integral and the effective capacity are used to estimate the energy efficiency and constant current charging–discharging time. Owing to the same energy‐oriented approach as is used in defining the effective capacity, the static model based on this capacity shows its superiority in estimating the efficiency and capacitance over another static model based on the integral capacity. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(4): 29–37, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21300     

Multiple coupled circuit modeling of induction machines

A new multiple coupled circuit model is presented for simulation of induction machines with both arbitrary winding layout and/or unbalanced operating conditions. The model is derived by means of winding functions. No symmetry is assumed. The parameters of the model are calculated directly from the geometry and winding layout of the machine. The behavior of an induction machine during starting is simulated using this model. The results are shown to be in good agreement with the solution obtained by a conventional d-q model for symmetric conditions. The new model is then extended to the solution of a wide variety of fault conditions such as broken bars and end rings and open or short circuited motor coils     

Capacitor modeling at high frequencies-a pedagogical example of theapplication of distributed circuit analysis for introductoryelectromagnetics or microwave courses

A structure consisting of two parallel plates, ordinarily identified as a plane capacitor, is analyzed from the viewpoint of a distributed parameter system. The results presented are not intended to be innovative, but may prove to be helpful to electrical engineering students in the process of understanding the issues involved in the modeling of circuit components, especially when high frequency regimes are considered     

Performance analysis and circuit design of high-frequency resonant inverter using a single reverse-conducting device

This paper is concerned mainly with a performance analysis and a design method of a newly developed zero-current switching quasi-resonant high-frequency inverter (ZCS-QRI) using a single reverse-blocking power device (high-frequency GATT). As a matter of fact, GATT is replaced by the latest MOS-gate power semiconductor devices, MOSFET, IGBT, MCT and Bi-MOS · GTO thyristor. The frequency-modulated single-ended inverter circuit, which incorporates an auxiliary diode and large reactor cascade branch in parallel with a resonant capacitor connected into the transformer-link series-resonant tuned tank load circuit can stably and efficiently operate in the frequency range from 20 kHz up to 50 kHz or so. It is proved that the ZCS-QRI is more suitable for several kilowatt induction-heating and melting power supplies and high-intensity ultrasonic generator, and switched-mode dc-dc converters. This simple high-frequency ZCS-QRI for induction-heating load model is analyzed introducing normalized resonant and load circuit parameters and control variable on the basis of computer-aided simulation. The load and frequency regulation characteristics of ZCS-QRI and ZCS operating range are illustrated with a normalized expression in addition to voltage and current peak values and stresses of the power semiconductor device. The practical computer-aided design procedure using the inverter characteristics in steady-state expressed in the normalized technique is demonstrated and discussed including a design example. The simulation results of ZCS-QRI are illustrated and compared with the experimental results in trial-produced breadboard.     

锂离子电池碳纳米管复合负极材料的进展

综述了碳纳米管(CNT)及复合材料在锂离子电池负极中的研究进展,重点论述了合金/CNT复合负极材料结构设计与制备方法的进展.CNT不仅缓冲该复合材料在嵌脱锂时的体积变化,形成的三维导电网络还可提高材料的倍率性能和循环寿命.展望了CNT复合负极材料的研究前景.     

Integrated coordination and short circuit analysis for systemprotection

A coordinated set of data management and analysis programs, already in use at several major utilities in the USA, is presented. The programs are known as the computer-aided protection engineering (CAPE) system. CAPE consists of an integrated set of ten data management and analysis programs designed to assist protection engineers with their day-to-day activities of selecting, setting, and coordinating protective relays. Underlying all the CAPE programs is a comprehensive (and general-purpose) relational database of both system and protective service data. The practical of two of CAPE's modules, Coordination Graphics and Short Circuit, for readily identifying and correcting miscoordinations is discussed. Both distance and overcurrent protective devices are treated. Realistic examples illustrate the detection of miscoordination. Corrective actions are taken using graphical manipulations (curve dragging) and direct specification of taps, test points, or desired reach     

电容器用金属氧化物/碳纳米管复合材料进展

电化学电容器电极材料中,金属(如Ru、Mn、Ni、Co和V)氧化物电极材料可进行快速法拉第反应,具有较高比能量,但其电化学可逆性差,功率性能差;碳纳米管(CNT)电导率高且表面利用率高,具有较高的比功率,但由于依靠双电层储能,比能量难以提高.将金属氧化物与碳纳米管复合制备复合电极,可综合利用二者的优点,同时获得较高的比能量和比功率,综述了金属氧化物/碳纳米管复合电极的研究现状及进展.