基于FPGA及LVDS的大尺寸测量系统设计

目前CCD成像物体尺寸测量系统中存在大物体尺寸测量精度低、抗干扰能力弱、控制复杂且成本高等问题;因此,设计了一种基于FPGA及 LVDS的具有抗干扰能力的大物体尺寸测量系统。该系统通过自扫描光电二极管列阵(SSPD)完成数据采集,经过A/D量化后经由LVDS芯片传输,完成信号噪声的滤除,然后由FPGA调用内部IP核对数据进行缓存,最后将数据传送到上位机进行实时显示。实验结果表明,该系统具有较强抗干扰能力、高速处理能力并且操作简单、成本低,同时实现了对大物体尺寸测量且具有较高精度。     

基于FPGA和DSP的瞬态测量系统的设计

为实现短暂时间的瞬态测量和信号存贮处理,为此专门设计了包含高速A/D、FPGA和DSP的瞬态测量系统,FPGA实现对瞬态信号测量控制和采集,DSP实现数据处理和传输,针对系统工作环境的干扰问题,提出了提高系统电磁兼容性的具体措施.这些措施包括感应线圈设计、电磁屏蔽、滤波技术、接地设计以及PCB设计.通过试验表明,在有干扰的情况下,该检测系统完全能够实现瞬态信号的全程检测.     

基于FPGA的超声数据采集装置的设计与实现

为了实现对某航天器在地面及飞行过程中的超声数据进行高精度、高速采集的功能,根据测量系统的技术要求,设计数据采集装置的硬件电路和时序控制逻辑。为了满足恶劣的环境测试要求,设计采用高速、高精度、宽温度范围的THS1408模数转换器。选取高速运放AD8028进行信号调理,以FPGA作为逻辑控制器,控制THS1408进行模数转换。经测试,采集精度优于0.5%,满足实际工程需要,具有很高的可靠性,已成功应用于该测量系统。     

FPGA在信号测量中的应用

在电信号测量领域,逻辑信号的测量十分重要.分析FPGA在逻辑分析仪测量高速信号中的应用.在FPGA内部实现对高速信号采样和存储,采样结束后,单片机读取数据,进行运算和显示.通过测试,用该方法制作的实物可以测量5 MHz的逻辑信号.设计利用FPGA高速运行的优势弥补单片机在测量高速信号中的不足.     

基于FPGA的多通道高速信号采集器的设计

采用FPGA技术设计的高速数据采集器可实现采集高速信号并实现实时上报的功能。利用FPGA,外部只需添加简单的电平转化电路即可灵活实现多通道、多主机、多路径实时数据传递。该系统信号采集速度快,接口类型多样,当应用到工业现场后还可以通过RS485总线进行远程升级来满足后续工程的需要而不需要对硬件做任何更改,比传统的数据采集系统有更强的竞争优势。     

基于FPGA+ARM的多路光栅数据采集系统设计

为实现对多路光栅数据进行高速采集以及远程传输,设计了基于FPGA+ARM架构的光栅数据采集系统.该系统以现场可编程逻辑门阵列(FPGA)实现对多路光栅数据同时进行高速采集、存储和传输,以ARM微处理器为核心,实现数据处理和以太网传输功能,通过对以太网协议栈的移植,实现了与PC端以TCP/IP协议完成以太网通信.通过实验...     

基于线阵CCD的精密尺寸测量系统

现有尺寸测量方式精度低,测量费时费力。为了 提高尺寸测量的精度,使测量系统便携化,操作简单, 文中实现了一种基于线阵CCD的精密尺寸测量系统。文中提出新的象元细分方法,将2个像 元间距为8μm的 线阵CCD等距错排并以60°斜放,可突破像元间距对测量精度的限制, 将最大测量误差减小为2μm,在此 基础上采用浮动阈值方法进行数据处理,实现高精度尺寸测量。利用FPGA进行硬件描述实 现线阵CCD的驱 动,对CCD的输出信号进行差分放大,采用硬件滤波方法消除曝光积分和转移过程中的电子 学噪声,采用10 位模数转换器实现数字量的并行输出,FPGA内部FIFO存储数字量结果。系统充分利用FPGA 的可编程资源, 有效降低了硬件设计复杂度,无需上位机或者ARM,节约成本,系统小型化便携化。实验表明, 该系统有效克服 光源及电子学噪声影响,可对1mm－29 mm的中型尺寸物体进行测量 ,误差小于2μm。     

基于嵌入式微处理器和FPGA的高精度测频设计

根据等精度测频原理,设计实现了基于嵌入式微处理器SEP 3203和FPGA的测频系统,给出了系统的硬件组成和软件设计流程。在一片FPGA上实现宽范围、高集成度、高速、高精度和高可靠性的频率测量和数据处理,并和嵌入式微处理器SEP 3203实现通信,达到了将嵌入式微处理器灵活的控制功能与FPGA器件的有机结合。最后给出该设计方案的实际测量结果,达到了较高的频率测量精度。该系统已经应用于一款无纸记录仪中。     

基于FPGA的时间间隔测量系统的设计

为了解决电容充放电放大电路测量时间间隔的不稳定,采用复杂可编程芯片FPGA设计实现精密时间间隔的测量。FPGA的锁相环（PLL）电路得到高频时钟,时钟管理器（DCM）实现高速时钟移相,内插时钟得到高精度时间测量。通过在光电回波脉冲时间间隔测量系统中验证,该设计可以得到200ps的时间间隔测量精度。采用FPGA芯片设计的数字化测量系统,具有集成度高,性能稳定,抗干扰强,设计方便等优点,能广泛应用于科研和生产中     

脉冲激光测距中高速精密时间间隔测量研究

在脉冲激光测距系统中,设计实现了基于FPGA和TDC-GP21的高速精密时间间隔测量系统。采用TDC-GP21的高精度测量模式,配置TDC-GP21完成了时间间隔测量,通过校准测量对测量结果进行补偿修正,提高了系统的测量精度;设计了多级嵌套状态机实现高速SPI通信,减小了系统单次测量周期;分析了影响测量精度的因素,比较分析了3种时刻鉴别方法的漂移误差,设计了高通阻容时刻鉴别模块,减小了系统的非线性误差。实验分别进行了基于FPGA脉冲信号的时间间隔测量和激光测距试验,对比验证了系统的测量误差,分析了系统在测量区间的线性度。实验结果表明,系统可以实现高速稳定测量,线性度良好,重复测量频率达1kHz,测量精度在±100ps内。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

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.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

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.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

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.     

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