基于FPGA的电机测速系统设计

研究的是基于FPGA的电机测速系统设计。该设计以有源晶振来产生时基信号,利用欧姆龙光电编码器E6B2-CWZ6C360P/R将转速信号转变为频率信号,采用数码管动态显示来显示测量所得的数值。FPGA模块的编写是基于Altera公司的Quartus II软件进行编写的,采用的芯片型号为EP2C5T144C8N。FPGA模块是利用VHDL语言进行编写,利用Quartus II软件自带的仿真软件进行仿真,通过观察仿真波形来验证模块是否正确。本设计可以实现小数值的方波频率测量和电机转速测量。     

灰度梯度自适应阈值二值化算法的FPGA实现

根据红外图像中目标与背景之间灰度比梯度特性,提出了一种自适应阈值二值化算法,并利用FPGA并行流水处理特点,采用模块化设计,完成了该算法的FPGA实现.算法实现由灰度比二值化模块和自适应阈值T模块两部分组成.灰度比二值化模块根据同步信号流水计算模板内灰度比梯度,并根据差值大小进行二值化.自适应阈值T模块根据背景的变化规律实时调整输出阈值大小,以实现对灰度比二值化模块作用范围的控制.实验结果表明,该算法虚警率较低,运算耗时少,满足实时处理的要求.     

一种基于FPGA的计算机层析重建的方法

提出一种基于FPGA的计算机层析重建的方法,即借助FPGA的高速数据处理能力来提高计算机层析重建的速度.采用自顶向下的方法,将FPGA依据功能划分为几个模块,并详细论述了各个模块的设计方法和控制流程.FPGA模块的设计采用VHDL语言编程和内部已有的小模块相结合的方法来实现,并利用时钟信号对模块内部以及模块之间运算和数据流程进行控制.整个软件设计和综合模拟仿真在Quartus ||开发平台中完成,同时也给出了一些模块仿真的波形.     

LTE/GSM多模基站收发信台数字中频模块故障诊断的新方法

针对LTE/GSM多模基站收发信台（BTS）开发中FPGA数字中频模块故障诊断的需求,开发 了一种基于以太网数据通信接口,利用Matlab软件直接存取FPGA内部寄存器值,并且可以连 续采集数字中频模块内部关键节点大块数据的软硬件协 处理方法,从而快速定位数字中频信号链路的调测问题并帮助排除故障。这种诊断方法无缝 集成在FPGA设计中,可以在BTS测试开发的各个阶段采用,不需要额外设备及接口。在LTE/G SM MSR（Multi-Standard Radio）项目中利用该诊断技术完成了数字中频模块上下行信号 处理链路频谱异常等故障的诊断与定位。     

基于FPGA的DDS设计及实现

针对DDS频率转换时间短,分辨率高等优点,提出了基于FPGA芯片设计DDS系统的方案。该方案利用Altera公司的QuartusⅡ开发软件,完成DDS核心部分即相位累加器和ROM查找表的设计,可得到相位连续、频率可变的信号,并通过单片机配置FPGA的E^2 PROM完成对DDS硬件的下栽,最后完成每个模块与系统的时序仿真。经过电路设计和模块仿真,验证了设计的正确性。由于FPGA的可编程性,使得修改和优化DDS的功能非常快捷。     

老式汽车加装转速表

转速表是汽车实现节油的重要仪表,遗憾的是许多老式和小型汽车却没有。加装本文介绍的自制转速表可以弥补这一缺陷,有助于节省能源。 制作汽车转速表的首要步骤是选用合适的传感器。实践证明,采用霍耳效应传感器来测量汽车引擎的转速,不仅简单易行,而且具有较高的精度。本转速表是在汽车发电机的皮带轮上安装一块小磁铁,由装在该皮带轮附近的霍耳效应传感器来检测小磁铁磁场旋转的速度。由     

基于ARM7和FPGA的风扇散热系统温控模块设计及实现

文中设计了一种基于ARM7和FPGA的风扇散热系统温控模块,定时采集散热系统温度以及风扇转速,实现了对风扇的PWM输入信号的实时控制,完成了温控模块的电路和软件设计,并对其应用功能进行了仿真测试。     

基于FPGA的信号频谱分析系统

利用FPGA实现了信号的采集与频谱分析系统,对系统进行了模块划分,并分别给出了各模块的设计要点,完成了模拟信号采集模块、快速傅里叶变换模块、存储模块以及VGA显示模块的设计。最后对设计的各模块进行了功能与时序仿真,验证了系统设计的正确性与可靠性。试验表明,该设计可以实现信号的采集、频谱分析与显示等功能,系统稳定可靠。     

基于FPGA与谐波合成信号发生器的实现

提出一种结合傅里叶级数展开和DDS原理产生任意波形信号发生器的实现方法。利用FPGA设计了15个DDS模块,将一周期正弦波的样值写入DDS模块的ROM表。对目标信号进行傅里叶变换得到信号各次谐波的频率和幅值,取其1~15次谐波的频率作为每个DDS模块的频率控制字,将各个DDS模块输出的样值与输入该模块的频率对应谐波幅值的乘积进行累加,经低通滤波器输出最终所需波形。测试表明,利用该实现方法得到的信号发生器输出波形稳定、频率转换速度快、精度在0.002 79 Hz以内。     

基于FPGA的WIM压电式车辆动态称重信号采集系统的设计

为解决汽车动态称重系统中，实现多通道称重传感器信号采集的问题，设计了一款基于“FPGA”的WIM压电式车辆动态称重传感器的多通道高速数据采集系统，该数据采集系统可实现对多车道动态称重传感器信号的同步采集、存储、传输和处理。采用FPGA作为信号采集单元，带有2片2G的高速数据存储SDRAM模块用于多通道的数据存储；采用分辨率为16位，采样率为1Msps的AD采集模块，设计可实现最多16通道的信号采集。上位机系统中搭载嵌入式操作系统，用于完成动态称重的信号处理，其通过PCIe总线可实现与FPGA的数据传输。经过实验验证，该数据采集系统可同步实现16通道，车辆以最高120Km/H时速行驶通过压电式动态称重传感器的信号采集、存储和处理。     

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.     

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.     

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.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.