一种高稳定性压电驱动电源设计

作为电压控制型器件,压电陶瓷驱动电源的稳定性受负载电容量变化的影响严重。针对负载等效电容在驱动电压变化下的动态特性,首次提出了一种基于容性负载的压电驱动电源。该电源采用RC前置滤波与电容超前反馈相结合,提高了系统稳定性与驱动电源的鲁棒性。分析结果表明,额定负载为1.5μF的驱动电源优化后在0～3μF内具有良好的动态性能,且输出电压精度达0.7 mV。     

一种大容性负载的压电陶瓷驱动电源设计

压电陶瓷作为微定位系统的动能器件,可达到纳米级的位移精度。针对位移驱动型压电陶瓷的大容性负载特点,基于PA92设计了一种高精度、大电流的动态驱动电源。通过电容超前反馈、隔离电阻结合反馈及相位补偿等方式提高了电源的稳定性。分析结果表明,该电源能有效应用于纳米级定位系统中,在大容性负载时具有良好的动态性能,输出电压精度可达0.5 mV。     

一种宽频带压电陶瓷驱动电源补偿方法研究

压电陶瓷驱动电源工作于容性负载时,恰当的环路补偿是电源稳定工作的必要条件。为提高压电陶瓷驱动器的响应速度,同时改善传统补偿方法仅补偿单极点的缺点,在分析传统压电陶瓷驱动电源补偿方法的情况下,该文提出一种高精度宽频带压电陶瓷驱动电源补偿法,实现了对极点频率低及多极点的大容值负载驱动电路的环路补偿。等效电容6.4μF的压电陶瓷为负载时,样机带宽可达5 kHz,上升沿和下降沿时间为200μs,纹波电压小于80 mV。实验结果表明,所提方法具有较优异的带宽及良好的稳定性,可应用于机器人、微位移运动平台及航空航天等压电应用领域。     

高精度大功率压电陶瓷驱动关键技术

压电陶瓷驱动电源是压电陶瓷微位移系统中的关键部件。以高压功率放大器PA93为核心,提出了一种新型高精度、大功率压电陶瓷驱动电源,适合驱动大行程、大推力压电陶瓷致动器。重点阐述了电路的设计方案,对复合放大电路进行了特性分析。实验结果表明,该驱动电源具有精度高,输出电压高,电流大,稳定性好的特点。当驱动等效负载电容为24 μF的压电陶瓷时,在0~100 Hz频率范围内实现了0~10 V信号到0~100 V信号的动态放大,输出电压精度优于3×10-5,最大输出电流350 mA。     

一种数控电位器调节的压电陶瓷驱动电源

设计了一种用于驱动数字共焦显微仪压电陶瓷物镜驱动器,实现数控电位器调节的压电陶瓷驱动电源,由单片机系统、前级高压稳压电路、数控电位器、功率放大电路、高压稳压电源和放电回路组成。采用前级高压稳压代替电压放大级作为输入,通过高分辨率的数控电位器调节,经功率放大和放电回路后驱动压电陶瓷驱动器。该驱动电源输出电压稳定,数控可调且随输入电压呈线性变化,可实现对电压精密控制,适用于驱动压电陶瓷等容性负载。     

基于恒流源的改进型压电陶瓷高压驱动电源

恒流源压电陶瓷驱动电源具有结构简单及频响好等优点,但静态功耗高是其突出缺点。该文提出了一种改进的恒流源压电陶瓷驱动电源,在静态功耗一定的情况下,提高了其动态输出能力及竞争能力。该改进型压电陶瓷驱动电源的样机具有2.4~300V的输出电压范围,在静态恒定电流为0.1A时,动态输出电流最大可达0.44A。基于恒流源的高压驱动电源,驱动电压主要由驱动管的耐压决定,原理上可得到远高于现有高压运放的水平,在高压压电陶瓷驱动方面有广阔的前景。     

一种高压压电陶瓷驱动电源的设计

为了满足压电陶瓷在振动平台微位移测试系统中输出更大范围的微位移及保持更高精度的条件,设计了一种高压大电流、带有直流偏置可连续调频调幅的正弦波输出压电陶瓷驱动电源。该文介绍了该驱动电源的设计方案、关键电路设计、控制系统软件设计及实验测试。该驱动电源以全桥逆变电路、隔离直流-直流抬压电路为核心,采用电压、电流双闭环比例-积分控制正弦脉宽调制(SPWM)波的基波来调节输出电压。通过搭建实验平台,验证了当压电陶瓷电容为5μF时,该驱动电源能实现在5 Hz～1 kHz频响内电压100倍增益放大,输出0～1 000 V的动态正弦电压,最大输出功率达到7 kW。结果表明,设计的压电陶瓷驱动电源具有输出电压高,输出功率大,频率响应快,且减小了电源整机体积和质量。     

一种压电陶瓷执行器动态驱动电源

针对压电陶瓷执行器呈现强容性负载的特性,该文研究了基于误差放大原理的压电陶瓷执行器动态驱动电源,提出采用高压运算放大器结合准互补对称功率放大电路构成的输出级以提高驱动电源的输出电压范围的方法和采用多组准互补对称功率放大电路构成的输出级并联以提高输出峰值功率的方法。通过对实际电路的测试表明,采用上述方法开发的压电陶瓷执行器动态驱动电源不仅输出功率达270 W,且具有良好的静态性能。     

压电式点胶机驱动电源研究

为满足压电陶瓷对驱动电源连续可调和快速响应的要求,同时改善传统驱动电源效率低、输出波纹大等缺点,该文采用一种直流逆变原理和电压控制驱动方案,并进行了理论分析和实际的电路实验。结合主功率电路和控制电路,采用交流直流变换、功率转换、整流滤波输出直流电压,结合脉宽调制控制芯片,经采样反馈调节高频逆变器的占空比,从而调节输出电压的大小,采用半桥驱动方式实现负载的驱动。当驱动等效负载电容为6.4μF的压电陶瓷时,在0~1kHz频率范围内实现输出电压0~200V连续可调,波纹电压小于10mV,上升沿的时间只有75μs,能满足点胶机的工作要求。     

压电陶瓷驱动电源研制及其在打印机中的应用

针对压电喷墨打印机的工作特点研制了一种压电陶瓷驱动电源。它能提供正、负输出,并能对压电陶瓷进行双向快速放电。输出电压可达±100 V(峰-峰值)。单路输出电流大于20 mA,驱动脉宽在5~200μs内连续可调,可实现多个串联的压电陶瓷致动器并行驱动。实验结果表明,该电源可满足压电喷墨打印机的驱动要求。     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.