基于FPGA的数据采集系统设计

设计了以FPGA为核心逻辑控制模块的高速数据采集系统.设计中采用了自顶向下的方法,将FPGA依据功能划分为几个模块,详细论述了各模块的设计方法和控制流程.FPGA模块设计使用VHDL语言,在Max＋PlusⅡ中实现软件设计和完成仿真.本文给出了一些模块的仿真图形.整个采集系统可实现24路最大工作频率为100 kHz的现场模拟信号采集和4路频率信号采集,且该系统也采集8路系统内部通道信号以达到自校验功能.     

基于FPGA的多路光电信号采集存储系统设计

针对激光光幕法测试弹丸坐标时需要采集多路光电信号的问题,提出了以FPGA为采集及控制芯片,以FLASH为存储芯片的多路光电信号采集与存储系统的设计。通过将采集到的光电信号缓存在FPGA内建FIFO中,然后对该信号进行处理并存储在FLASH中,使用USB接口与上位机进行通信传输。仿真结果表明,该系统可成功将64路光电信号采集并存储,结构灵活、操作简单,数据准确且存储量大。     

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。通过实验验证,证明该系统具有良好的准确性和稳定性,可以满足光栅数据采集及传输的要求。     

基于FPGA和USB2.0的多路音频信号采集系统

本文介绍了一种基于FPGA与USB2.0的多路音频信号采集系统。采用XILINX公司的FPGA为控制芯片,以USB2.0为接口实现FPGA和PC机之间的高速数据传输。通过软硬件技术的结合实现了对多路音频模拟信号的采集。并介绍了固件(fireware)和USB设备驱动软件的开发。     

基于FPGA和USB2.0的光电探测系统研究

自由空间光通信已引起广泛注意。在工业和科研等领域生产过程中探测光电信号,对探测信号数据处理要求也日益严格。本文提出以FPGA芯片EP2C5Q208C8为主控芯片,利用TLC5510进行多路的、同步的模数转换,对光电信号进行数据采集,从而实现较高精度的多路光电数据采集系统设计。通过软硬件编程,该系统可以实现8路、8位有效数据位光电信号采集,经FPGA处理和USB2.0通信完成光电探测数据采集显示功能。     

基于FPGA和USB2．0的多路音频信号采集系统

本文介绍了一种基于FPGA与USB2．0的多路音频信号采集系统。采用XILINX公司的FPGA为控制芯片,以USB2．0为接口实现FPGA和PC机之间的高速数据传输。通过软硬件技术的结合实现了对多路音频模拟信号的采集。并介绍了固件（fireware）和USB设备驱动软件的开发。     

嵌入式多路视频采集显示系统设计

针对当前嵌入式领域中多路视频采集显示系统的问题,提出了一种基于FPGA的新方案。给出了系统的组成结构,详细分析了设计原理和关键性问题。使用状态转移机实现了I2C总线协议和TFT-LCD控制时序信号的产生,基于分时复用技术实现了对多路视频信号采集的同步,利用双SRAM切换技术解决了读写显示缓存的冲突问题,采用组帧技术完成了隔行扫描到逐行扫描的变换。经工程化验证,系统具有采集显示效果好、成本小、功耗低等优点。     

基于FPGA的数据采集系统设计

提出一种基于FPGA技术的多路模拟量、数字量采集与处理系统的设计方案,分析整个系统的结构,并讨论FPGA内部硬件资源的划分和软件的设计方案等。本设计方案外部电路结构简单可靠,特别适用于多路检测系统中,而且可以根据需要容易地对系统进行扩展,对于检测系统来讲具有一定的通用性。     

基于FPGA和DSP的多路信号采集系统的设计

描述了一种能够采集16路模拟信号并具有实时数据处理能力的多路信号采集与处理系统。该系统采用高速A/D转换器将多路模拟信号转换成数字信号,以FPGA为控制核心产生各种控制时序,利用DSP对采集后的数据进行实时地处理并用CCS3.3软件平台在计算机实时显示处理后的波形图。概述了整个系统的构成,将FPGA的外接双口RAM和DSP的EMIF接口连接,实现了FPGA和DSP的数据通信。为了消除周围电磁环境、传输线长度等因素的干扰,提出了采用自适应滤波消除噪声的设计原理。实验结果表明,该系统工作稳定,实现了对采集信号实时处理。     

基于FPGA的高速数据采集系统的设计

本设计采用了以FPGA作为主控逻辑模块,从而实现了数据的硬件采集。设计中采用了自顶向下的方法,并将FPGA依据功能划分为几个模块,详细介绍了各个模块的设计方法和功能。FPGA模块设计采用VHDL语言,在QuartusⅡ中实现了软件的设计和仿真。整个系统可以实现6路最大工作频率是40kHz的模拟信号的采集和6路内部通信信号以实现自检的功能。     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

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.