基于ADMCF340的永磁无刷直流电机控制系统设计

随着直流无刷电机应用领域的不断扩大,对控制系统的稳定性和实时性提出了更高的要求。以DSP芯片AD-MCF340为控制核心,设计了永磁无刷直流电机的控制系统,并给出了部分硬件电路图和控制软件流程图。该系统利用DSP芯片的快速运算功能和面向电机控制的专用外围设备,实现了电流、速度的全数字双闭环控制。研究结果表明,该系统稳定可靠,实时性良好,为永磁无刷直流电机的广泛应用提供了一定的理论参考依据和工程实际方法。     

首批奥运TD手机移交中移动

7月30日,联想移动携手芯片厂商展讯通信,正式向中国移动交付首批200台支持数字电视功能的TD—SCDMA手机联想TD900。据悉,此次交付的200台TD手机主要用于赠送奥运会志愿者及相关工作人员。由于加载了广电的CMMB手机电视芯片．TD900可以免费收看7～8套电视节目和收听多套广播频道。此前,中国移动为服务奥运,进行了4万台数字电视手机的招标,联想取得其中3000台采购订单。     

TD终端销量突增 芯片已供不应求

多位TD业内重要人士证实,下半年TD终端销量突然开始放量大增,TD芯片已供不应求,预计到年底才能改观。TD产业联盟秘书长杨骅也证实,目前确实存在TD芯片供不应求的局面。他分析称,应该是前期TD市场发展不如预期,因此芯片厂商在芯片的备货上准备不够,终端厂商在器件的备货上数量也都比较小,     

GALAXY S III采用展讯TD基带芯片

展讯通信有限公司日前宣布其TD—SCDMA基带芯片——SC8803C与RF收发器——SR3200被三星选定，用于中国移动定制款最新顶级TD—SCDMA智能手机GALAXY S III（GT—19308）。     

广晟微电向TD更高处挺进

广晟微电子有限公司致力于推动中国TD射频芯片的发展，2008年成功将第一代TD—SCDMA射频芯片推入市场。广晟微电子第一代TD—SCDMA射频芯片的市场占有率超过70％，目前，广晟微电子TD—SCDMA射频芯片已被国内一大批企业采用，并得到了产业链下游企业的高度认可，在射频集成电路核心芯片领域奠定了坚实的行业基础和市场地位。采用广晟微电子射频方案的HSDPA数据卡实现大规模商用，北京奥运会TD数据卡绝大部分采用广晟微电子的射频方案。     

工信部：TD—LTE亟需发展多模芯片和终端

在日前举行的“2011TD—LTE组网技术研讨会”上,工信部科技司高技术处正处级调研员叶林表示,从全球目前TD—LTE的发展来看,多模芯片和终端依然是一种发展趋势,目前TD—LTE、FDD—LTE都需要发展多模芯片和终端,工信部将积极推动相关芯片企业抓紧开发TD—LTE的多模芯片和终端。初期已经明确,TD—LTE、TD—SCDMA、GSM为多模必选模式,后期将支持TD—LTE、FDD—LTE多模的方案。     

大唐推出首款TD—LTE双模基带芯片

针对即将开始的我国TD—LTE规模试验,大唐电信集团旗下芯片子公司联芯科技1月6日宣布,推出业界首款TD—LTE／TD—SCDMA双模基带芯片LC1760,将可实现TD-LTE和TD—SCDMA双模自动切换,为此次测试打下终端芯片基础,并将于今年年中推出TD—LTE双模数据卡。     

创毅视讯展示TD—LTE研发成果

9月16～20日,在2009中国国际信息通信展上,创毅视讯科技有限公司作为TD—LTE基带芯片核心研发企业,在TD联盟展台芯片展区设立了展位,展示了最新研发的基于TD—LTE技术的仿真平台系统。     

Allegro MicroSysstems推出新型无刷直流电机驱动芯片

Allegro MicroSystems最近推出一款用于三相无刷直流电机控制的全桥驱动芯片A4931,新产品提供最大38V输出,可直接驱动需要大电流门极驱动信号的N通道MOSFET三相全桥。该芯片还带有3路霍尔元件输入用于控制触发逻辑,并且具备转于锁定保护功能。     

联芯、联发科携手发布业内首款TD-HSUPA芯片及解决方案

目前TD终端芯片领域中最重要的供应商“联芯／联发科”组合,携手发布业内第一款支持TD—HSUPA的TD芯片Laguna—U（最高下行速率2．2Mbps）、以及基于此芯片的终端解决方案A2000＋U。相关方面称,依据目前客户的项目导入进度,支持TD—HSUPA的手机终端产品有望在2009年初推向市场。     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks