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1.
5类电缆性能测试的基本指标   总被引:2,自引:0,他引:2  
马宏斌  谭斌  杨波 《信息技术》2005,29(5):98-99
结构化布线工程的最后一步是对布线系统的测试和评估,电缆的性能测试经常被忽视,基本指标有:近端串扰,综合近端串扰,衰减串扰比,等效远端串扰,综合等效远端串扰,回波损耗,延迟抖动等。  相似文献   

2.
TP—Link首次推出数字通信用增强型五类非屏蔽水平对绞电缆。目前,全线产品通过信息产业部质量检验中心的测试,数据不仅合格,并且其性能远远超出标准要求。TP—Link对线缆的传输上也有非常细腻的考虑,使衰减、阻抗、远端串扰方面的性能达到优秀,并且全面超越ANSI/TIA/EIA-468-B.2标准对超五类电缆的要求。TP—Link电缆温度控制在-20~70℃。  相似文献   

3.
在电子装联工艺中,互连线间的电磁耦合(串扰)是电子整机内各模块间互连线缆及模块内PCB印制迹线布线的主要考虑因素,本文通过对互连线的串扰分析,提出以有限元计算及电路仿真软件为工具,对布线的串扰进行预测。  相似文献   

4.
信道带宽是评判通讯布线性能的一项最重要的参数指标。下一代标准如6类或7类标准与原有的较低类别标准的不同之处就在于有效带宽的不同。一般而言,在布线系统中更高的带宽意味着更高的数据传输速率。1带宽的概念什么是带宽?在铜介质布线系统中,每百米双绞线信道的带宽通常用MHz来表示。信道带宽是指在信噪比确定不变的情况下的信道频率范围。今天,大多数的LAN系统所要控制的噪音来源是产生于传输线对与接收线对间的近端串扰(NEXT)。当所有的近端串扰源都被考虑到了,那么以分贝计量的信噪比与累加功率衰减串扰比(PSA…  相似文献   

5.
串扰是机载设备间互联线缆干扰耦合的重要因素。以混合模S参数为基础,建立单线-双绞线模型以模拟机载设备之间的动力线缆对信号线产生的串扰耦合。在此模型基础上提出串扰耦合测试方案,搭建串扰耦合测试系统,并根据测试获得的耦合系数评估单线-双绞线线间串扰耦合强弱。通过测试比较,对影响因素进行分析,结果表明,距地高度对线间串扰影响不大,线间距对线间串扰耦合影响显著,因此在条件允许下尽可能增加设备间互联线缆的间距可有效抑制串扰耦合。  相似文献   

6.
设计了一种基于串扰理论的线缆护套屏蔽效能的测试方法,根据测试结果分析了屏蔽护套不同接地方式对线缆间感性耦合、容性耦合的影响,试验结果可为在实际工程中抑制线缆串扰提供依据。  相似文献   

7.
新能源汽车主要依靠电力驱动,其电力线缆传输高电压、大功率的瞬变信号,加之线缆本身的天线效应,使其成为电动汽车中最主要的电磁干扰发射源。因此电力线缆极易对周围线缆产生串扰。通过分析电力线缆辐射电磁干扰的来源,利用FEKO仿真工具建立了电力线缆和相邻线缆的简化模型。通过改变仿真模型中线缆屏蔽层及金属线槽的设置,对比分析了这些因素对抑制串扰和干扰发射的影响。根据仿真结果,得出了降低线缆屏蔽层阻抗和增加金属线槽的使用,有助于抑制线缆串扰的结论。  相似文献   

8.
DWDM系统信道串扰因素的研究   总被引:1,自引:1,他引:0  
张颖  葛春风 《光电子.激光》1999,10(6):525-527,539
本文提出一种串扰模型,通过理论分析和数值计算,定量地描述了密集型波分复用(DWDM)通信系统中串扰与光源有效信号带宽,接受滤波器带宽有波长漂移的关系。所得结论对有效地控制信道串扰及在保证系统性能可靠的前提下降低通信成本方面具有指导性意义。  相似文献   

9.
用矩量法求解多导体传输线的分布参数,采用多导体传输线理论,建立了串扰模型,并用CST电缆工作室对线缆建模,验证了传输线模型的正确性,并利用所构建模型分析了城际列车上电源线NHWL1-3.5与信号线NH-WL1-1.25的线缆间距、线缆长度以及线缆端接负载对串扰的影响。  相似文献   

10.
王全永  吴兆华  何飞 《电子质量》2009,(11):71-73,78
电子设备中线缆所处工作环境越来越复杂,线缆之间的电磁串扰以及电磁损耗带来的热效应日益严重。针对这一问题,在电磁场、温度场和多场耦合相关理论的基础上,具体分析了线缆的电磁场和温度场相互影响的显著程度,基于在温度变化较小的情况下线缆的材料属性变化不明显,为了简化研究手段,只关注了从电磁场到温度场的单方向耦合。建立了线缆电磁-热耦合三维有限元仿真分析模型,采用Ansoft HFSS进行电磁场分析,同时将其分析所得电磁损耗作为发热源加载到Ansofte Physics中进行温度场分析。采用这种协同仿真方案,最终得到了不同线缆间距、绝缘层厚度和传输信号频率对电磁串扰及热效应带来的影响。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

18.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

20.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

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