一种适用于射频电子标签的低电压低功耗振荡器

提出了一种适合射频电子标签应用的振荡器设计方法．针对低电压低功耗的要求，选择了比较简单的振荡器结构，通过调节电流的方法来调节振荡器的输出频率．输出电流与电源无关的偏置电路设计保证了振荡器输出频率的稳定，低功耗的二进制权电流电路提供了很小的寄生参数、较高的电流精度和很小的芯片面积．芯片在Chartered 0.35μm CMOS工艺流片，电源电压为1.2～2V，环形振荡器消耗的平均电流约为6.5μA．     

以混频器作为信号处理单􀀂 元的环振式压力传感器

提出了一种新的环振式数字压力传感器，它采用做在硅梁上的MOS环形振荡器作为敏感元件，两个反方向变化的环形振荡器的输出信号通过集成在片内的混频器实现频率相减，分析了环形振荡器的频率特性，以及环形振荡器的谐振频率和压力的关系，分析并设计了压力传感器的环形振荡器电路、混频器电路、物理结构以及制作工艺，并制作了样品，其灵敏度为1．52kHz／kPa。     

RTD-HBT高速低功耗环形振荡器的分析

RTD与HBT是高频高速器件,共振隧穿二极管-异质结晶体管(RTD-HBT)环形振荡器有很好的应用前景.详细介绍了RTD-HBT高速低功耗环形振荡器的工作原理,建立了RTD,HBT及RTD-HBT环形振荡器的等效电路模型,并对RTD-HBT环形振荡器用Pspice模拟软件进行了电路模拟.模拟结果与预期结果一致,有助于指导该电路的设计.     

环形压控振荡器的噪声分析

在振荡器的设计中,为了得到更高性能,分析其相位噪声是十分重要的.利用Razavi对具有普遍意义的品质因数的定义将Leeson针对LC振荡器提出的相位噪声模型应用到环形振荡器上对其进行噪声分析.文中以一个2 GHz环形振荡器为例,采用TSMC 0.25 μm CMOS工艺参数,用Cadence的spectre仿真器进行仿真.电源电压为2.5 V,偏离中心频率1 MHz处的相位噪声为-86.6 dBc/Hz.仿真的结果与噪声模型所的结果基本吻合.     

一种频率稳定的集成CMOS环形振荡器

在分析传统的环形振荡器和一种改进型CMOS环形振荡器的基础上，提出了一种线路简单的环形振荡器。它的振荡频率随电源电压的变化很小，线路简单，具有很强的实用性。通过仿真，得到了电源电压和振荡频率的对应关系，取得了满意的结果。     

耦合式光电振荡器的理论与实验研究

为了研究耦合式光电振荡器,阐述了耦合式光电振荡器的模式选择理论,给出了维持最佳锁模状态的相位匹配条件,分析了影响射频信号相位噪声的因素,进行了基于保偏机制的耦合式光电振荡器的实验研究。采用分别调节光环形腔和光电微波振荡环路中的保偏可变光纤延迟线可改变腔长的方法,获得了腔长与振荡频率的关系。同时,采用鉴频法测量了不同条件下5GHz射频信号的相位噪声,研究了影响射频信号相位噪声的因素。结果表明,耦合式光电振荡器的振荡模式取决于光环形腔的腔长,射频信号相位噪声受到光信号偏振态、相位匹配、环路长度等因素的影响。实验中获得了偏移频率10kHz处相位噪声达到-136dBc/Hz的5GHz射频信号,是目前国内已知的相位噪声最低的耦合式光电振荡器。     

一种伪差分两级环形振荡器的设计

设计了一种伪差分两级环形振荡器,可为锁相环提供8 GHz四相位正交时钟。通过分析耦合两级环形振荡线性模型,对四级环形振荡结构进行优化,提出了伪差分两级环形振荡结构。基于单级缓冲器的开环分析,可对振荡器的输出频率进行精准估算,并判断振荡情况。采用65 nm CMOS工艺进行设计与仿真。结果表明,在1.2 V电压下,振荡器的功耗为6.9 mW,1 MHz频率处的相位噪声为－82.104 5 dB,满足高速SerDes接口的设计要求。     

门电路环形振荡器仿真研究

在测量门电路的传输延迟时间时,通常用门电路环形振荡器,但门电路环形振荡器振荡频率较高,对实验仪器设备的要求也较高,用仿真实验的方法有直观明了的优点,所以在数字电路教学中常用仿真的方法来进行实验.然而,在用仿真方法进行实验分析时,实验结果和实物实验或理论分析会存在一些差异.分别用EWB的2种版本仿真软件EWB 5和Multisim 9对门电路环形振荡器进行仿真,分析出现差异的原因,指出在用仿真方法进行数字电路仿真分析和设计时要注意的问题.     

一种适用于射频电子标签的低电压低功耗振荡器

提出了一种适合射频电子标签应用的振荡器设计方法.针对低电压低功耗的要求,选择了比较简单的振荡器结构,通过调节电流的方法来调节振荡器的输出频率.输出电流与电源无关的偏置电路设计保证了振荡器输出频率的稳定,低功耗的二进制权电流电路提供了很小的寄生参数、较高的电流精度和很小的芯片面积.芯片在Chartered 0.35μm CMOS工艺流片,电源电压为1.2～2V,环形振荡器消耗的平均电流约为6.5μA.     

一种实用的电压控制环形振荡器

本文介绍了两种在集成电路中得到广泛应用的，作为内部时钟源的环形振荡器，RC环形振荡器和电压控制环形振荡器，并对引起振荡频率变化的关键因素进行了分析。     

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.