高压大功率运算放大器PA85

1.概述 PA85是Apex公司生产的高电压、大功率宽带MOSFET运算放大器,它在安全操作区(SOA)没有二次击穿的限制,通过选择合适的限流电阻可在任何负载下选择适当的内部功耗.PA85可适应较大的电源电压范围并达到很好的电源电压抑制.MOSFET输出级可偏置成线性运放;用户通过外接补偿可轻松的使用PA85.     

非线性有源电阻网络的拓扑分析

将线性网络的拓扑分析法推广到非线性有源电阻网络,采用了非线性元件分段线性化的模型,将非线性有源电阻网络转化为分段线性有源网络。提出了非线性有源电阻网络"通解"、"特解"、"真特解"等新概念,使非线性有源电阻网络有了类似于线性网络的解析解。实验结果表明,这种方法具有良好的收敛性。     

一种适用于医学领域的频率可调滤波器

本文提出了适用于医学领域的R-MOSFET-C滤波器,采用MOSFET代替传统RC有源滤波器中的电阻,实现可调、超低截止频率。该滤波器采用UMC 0.13 m CMOS工艺,电源电压为1.2V。仿真结果显示,当外部可调电压,即MOSFET的栅电压在0.6V到0.84V之间变化时,截止频率可随之在0.2Hz到292.8Hz之间变化。     

一种用于MEMS电场传感器的CMOS可控增益前置放大电路

为了将基于MEMS技术的微型电场传感器与其信号处理电路集成在一个芯片上,设计了一种CMOS前置放大电路.该电路利用工作在线性区的长沟道MOSFET晶体管代替传统的无源器件做反馈来降低所占硅片面积,使用分流原理构建分流网络产生可编程的偏置电流来控制放大电路的增益.仿真结果表明该电路结构具有较好的线性度和很好的温度特性,长沟道晶体管的等效电阻与偏置电流相关,可以达到兆欧量级.     

一种红外探测器专用77K工作CMOS前置放大器

利用single-ehded folded-cascode结构和MOS管工作在线性区做反馈电阻,实现了一种在77K工作的高性能低功耗、低噪声前置放大器.分析了它的噪声特性,提出了减少噪声的措施.此前置放大器用1.2μm的标准CMOS工艺制造完成.经过测试,这种前置放大器在低温77K下能正常工作,反馈电阻大小为兆欧级,线性度达到了1%,等效输入噪声电流仅0.03pA/Hz,功耗小于1mW.     

一种采用SiGe HBT的新型超宽带有源可调衰减器

提出一种以SiGe HBT为有源器件的超宽带有源可调衰减器。在超宽频带内实现了宽增益调节范围和高线性度。详细分析了有源衰减器的最小插入损耗及最大衰减量,基于Jazz 0.35μm SiGe HBT工艺,通过选择合适的SiGe HBT有源器件,完成了超宽带有源可调衰减器的设计。利用安捷伦公司的ADS仿真软件,对设计的有源可调衰减器进行仿真验证。结果表明,在3.1～10.6GHz的超宽带内,当电压在0.4～1.8V的范围内变化时,该有源可调衰减器的增益动态范围大于50dB,S11在整个电压变化范围内均低于-10dB,且输入3阶交调点(IIP3)为13dBm。     

MOSFET-C连续时间滤波器原理与进展

MOSFET-C连续时间滤波器,是近十年来崛起的新型滤波器,其电路结构与传统的RC有源滤波器雷同,但MOS集成运放中所有电阻R均以MOSFET特性起始段的线性压控电阻取代,因此整个电路只含MOS管和电容器C,便于单片集成。“连续时间”一词,用来强调所处理的信号未经采样的原始模拟性质。它的出现,改变了有源滤波器在与集成化开关电容(SC)滤波器和数字滤波器竞争中陷入困境的局面.从而开辟了连续时间有源滤波器全集成化的新时代。     

700V最高启动电压的PWM控制器

高度集成的电压式PWM控制器NCP1280的有源钳位电路可提供高电压(高达700V)启动,为有源钳位电路提供了控制输出以驱动正向转换器初级MOSFET和辅助MOSFET,也可用带可编程延时二次输出来驱动次级或不对称半桥电路中的同步整流器。其他功能还包括一个700V启动电路、电压前馈、可调最长工作周期控制、高达500KHz的可调振荡器频率、线路欠压和过压监测器、双模式过电流保护和软启动,采用节省空间的SOIC-16封装。与传统的正向转换器拓扑相比,采用NCP1280的有源钳位方案提供了更低的开关和传导损耗,所需的输出感应器更小,降低了一次开关…     

一种红外探测器专用77K工作CMOS前置放大器

利用single-ended folded-cascode 结构和MOS管工作在线性区做反馈电阻，实现了一种在77K工作的高性能低功耗、低噪声前置放大器．分析了它的噪声特性，提出了减少噪声的措施．此前置放大器用1.2μm的标准CMOS工艺制造完成．经过测试，这种前置放大器在低温77K下能正常工作，反馈电阻大小为兆欧级，线性度达到了1％,等效输入噪声电流仅0.03pA/Hz，功耗小于1mW．     

642型晶体管兆欧表

642型晶体管兆欧表是上海冰箱修配厂1965年试制成功的新产品,其主要技术性能如下:1.兆欧测量:0～500兆欧,最小分度0.1兆欧,±1%(T-1型);0～1000兆欧,最小分度0.2兆欧,±1%(T-2型).2.电压测量:0～500伏直流,±1%,每伏1000欧.3.阻尼时间:不超过3秒钟.4.绝缘电阻:在温度20±5℃和相对湿度低于85%时,电路与外壳的绝缘电阻不小于20兆欧.5.     

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.