利用Visual C++开发Pro/ENGINEER三维标准库

从提高产品设计效率和质量出发,探讨了参数化设计功能和Pro/ENGINEER Wildfire环境下三维模型参数化设计的实现策略和途径,分析了基于Pro/TOOLKIT二次开发的三维标准件库参数化设计的过程,并给出了应用实例。     

皮秒光参量振荡放大器用于指纹印迹识别的研究

对不同载体上不同沾染物的指纹印迹特征用410～710nm可调谐激光进行荧光再现,再用滤色片将激光滤除,从而摄取清晰的指纹印迹荧光照片。     

周期极化掺镁铌酸锂光参量振荡器的输出光谱特性

实验研究了基于多周期的掺镁铌酸锂晶体光参量振荡器(OPO),分析了光学参量振荡器的输出光谱特性.实验中,采用激光二极管(LD)端面抽运的声光调Q Nd:YVO4激光器作为光参量振荡器的抽运源,谐振腔采用双凹腔结构.在调Q开关重复频率为10 kHz,周期极化掺镁铌酸锂(PPMgLN)晶体的温度为25.4℃的条件下,实验测得光学参量振荡器的振荡阈值为110 mW.当输入的抽运光的平均功率为325 mW时,获得了平均功率为84 mW的信号光输出,其光-光转换效率为25.8%.通过改变周期极化掺镁铌酸锂晶体的温度(25.4～120℃)和极化周期(28.5～30.5 μm),实现了信号光在1449.6～1635 nm范围内的可调谐输出.在室温25.4℃时,观测到了抽运光与信号光的和频光的光谱.实验结果表明.光参量振荡器输出光谱的半峰全宽(FWHM)小于0.5 nm.     

An Integrated CAD Methodology for Yield Enhancement of VLSI CMOS Circuits Including Statistical Device Variations

In this paper a novel CAD methodology for yield enhancement of VLSI CMOS circuits including random device variations is presented. The methodology is based on a preliminary characterization of the technological process by means of specific test chips for accurate mismatch modeling. To this purpose, a very accurate position-dependent parameter mismatch model has been formulated and extracted. Finally a CAD tool implementing this model has been developed. The tool is fully integrated in an environment of existing commercial tools and it has been experimented in the STMicroelectronics Flash Memory CAD Group.As an example of application, a bandgap reference circuit has been considered and the results obtained from simulations have been compared with experimental data. Furthermore, the methodology has been applied to the read path of a complex Flash Memory produced by STMicroelectronics, consisting of about 16,000 MOSFETs. Measurements of electrical performances have confirmed the validity of the methodology, and the accuracy of both the mismatch model and the simulation flow.     

超短中红外激光脉冲的产生及其发展状况

超短中红外脉冲对研究物理、化学、生物学和半导体内的超快过程等有非常重要的作用。介绍了参量振荡、差频产生、参量放大产生超短中红外激光脉冲的方法,及国内外相关研究的最新进展。     

基于三维参数随机L系统的虚拟植物生成算法

提出了一种基于三维参数随机L系统的虚拟植物生成算法.针对简单L系统生成植物形状单一的缺点,采用曲线论的Frenet标架作为三维基本框架,在对植物产生字符串进行递推迭代的同时,对其规则加入随机概率,使生成的字符串在具有随机性的同时又保留了自相似性.此外,对转角与步长均加入了随机扰动,使生成的植物形态在保持生物性状稳定性的同时又兼具了个体差异性,提高了生成植物的真实感.     

微石英音叉陀螺精度受参数变化影响的研究

电子元件的参数变化是影响微石英音叉陀螺精度的重要原因之一,该文论述了模拟开关参数变化对陀螺精度的影响,提出了一种新的相敏解调法及相敏解调电路,进行了与常规方法的对比试验,列举了两种方法的陀螺的零位偏置变化、零位稳定性、标度因数温度灵敏度及非线性度等指标的测量数据。试验结果表明,采用新方法的陀螺性能优于常规方法,可消除模拟开关参数变化对陀螺精度的影响。     

Test‐Generation‐Based Fault Detection in Analog VLSI Circuits Using Neural Networks

In this paper, we propose a novel test methodology for the detection of catastrophic and parametric faults present in analog very large scale integration circuits. An automatic test pattern generation algorithm is proposed to generate piece‐wise linear (PWL) stimulus using wavelets and a genetic algorithm. The PWL stimulus generated by the test algorithm is used as a test stimulus to the circuit under test. Faults are injected to the circuit under test and the wavelet coefficients obtained from the output response of the circuit. These coefficients are used to train the neural network for fault detection. The proposed method is validated with two IEEE benchmark circuits, namely, an operational amplifier and a state variable filter. This method gives 100% fault coverage for both catastrophic and parametric faults in these circuits.     

宽带、超宽带光纤放大器研究进展

目前,实现宽带、超宽带光纤放大器的技术主要有四种:宽带掺铒光纤放大(EDFA)技术、宽带拉曼放大技术、宽带混合放大技术和光纤参量放大技术.综述了宽带和超宽带光纤放大器的研究现状,并分别分析了其特点及发展趋势.     

双波长粉末倍频检测系统研究

为了测定粉末材料的倍频特性,根据Kurtz-Perry粉末倍频效应理论,采用光参量振荡技术,获取了130mJ@1064nm和20mJ@1570nm的双波长调Q激光输出,并进行了理论分析和实验验证。实现了粉末样品的1064nm和1570nm双波长倍频测试,解决了单一波长测试时晶体粉末材料对倍频信号波长的吸收而导致难以测得倍频信号的问题,有效非线性系数测试灵敏度达到0.46pm/V。结果表明,KTP粉末样品倍频信号变化趋势与理论相吻合,该系统对晶体的非线性检测运行稳定可靠,测试简单方便快捷。