LRC基带单元SDM(A)和SDM(B)相互切换失败的分析

LRC系统模块是4G基站的重要组成单元,它由LCP,LSP,LCA,LBR,LNI五大模块组成,主区SDM(A)和备区SDM(B)的切换是基于板卡LCA来完成的.在测试中按照制定的测试步骤进行对应的命令操作,发现SDM(A)切换SDM(B)失败,通过不同的测试分析,找到了引起失败的最终原因.     

信道的复用技术与多址技术

主要介绍了信道的复用技术和多址接入技术 ,并讨论了它们之间的联系与区别     

变频芯片的吞吐率测试方法

吞吐率作为衡量网络系统性能的重要指标,其重要意义毋庸置疑,掌握其正确的测试方法及分析手段尤为重要。对于XN277(三网融合变频芯片)而言,其射频指标诸如通道增益、噪声系数、本振相位噪声等对吞吐率均有不同程度的影响。文章通过实际的测试工作,重点阐述了不同的通道增益对吞吐率的影响,同时结合IxChariot的应用,对吞吐率的测试方法进行了详细的验证与分析。     

我国集成电路IP市场博弈之道

随着知识经济的蓬勃发展,知识产权(IP)这个名词已经为人们越来越熟悉,而知识产权的授权使用则一方面成为知识形态的产品进入商品交易的主要形式,同时也成为知识产权保护的主要手段;另一方面,它也成为知识产权(IP)供应商构筑技术壁垒,实现技术垄断乃至市场垄断谋取高额利润的必要手段,本文以作者在知识产权(IP)起关键作用的集成电路设计行业的亲身实践经验,通过对国际IP巨头的业务运作模式的分析,探讨我国正在迅速发展的集成电路设计业如何应对国外(IP)供应商构筑的技术壁垒,争取以合理的成本合法地获取国外知识产权(IP)从而实现跨越式发展,以及建立我国自身的IP产业的必要性及其面临的挑战和机遇,而在其过程中,对于急需获得IP授权完成芯片设计的Fabless设计公司而言,相信本文披露的一些IP厂商经营之道一定能帮助您把握市场先机,获得在IP授权交易中的主动权.……     

使用FIFO完成数据传输与同步(上)

将数据从一个时钟域同步至另一个时钟域,常用的两个方法为:1、使用握手(handshake)信号;2、使用FIF0.使用握手方法的缺点是传递及辩识用于数据传输的所有握手信号所需的潜伏时间(1atency)会增加延迟并降低传输效率.因此时钟域之间传递数据最常用的方法是使用FIF0.异步FIF0的运作(operation)方法是:数据从一个时钟域写入FIF0,该数据从另一个时钟域自FIF0读出.本文讨论两种异步FIF0的设计技巧:1、比较同步指针;2、比较异步指针.     

电路板级的电磁兼容设计

本文从元件的选择,元件的布局,电源布线,信号布线,地线设计等方面讨论了电路板级的电磁兼容(EMC)设计。     

导光板注塑成型技术的研究

导光板注塑成型技术是一种通过光学网点转移的方法成型导光板的技术,即将融熔树脂注入带光学网点的模具型腔,经过保压、冷却后脱模得到导光板,注塑成型得到的导光板具有模具型腔(stamper部分)所赋予的光学网点,这些网点的凹凸性和模具型腔网点的凹凸性互补。介绍了该技术的基本原理,通过工艺试验优化了相关工艺参数,证明了该技术用于导光板生产具有较高的精度和效率。     

Design and simulation of nanoscale double-gate TFET/tunnel CNTFET

A double-gate tunnel field-effect transistor (DG tunnel FET) has been designed and investigated for various channel materials such as silicon (Si),gallium arsenide (GaAs),alminium gallium arsenide (AlxGa1xAs) and CNT using a nano ViDES Device and TCAD SILVACO ATLAS simulator.The proposed devices are compared on the basis of inverse subthreshold slope (SS),ION/IoFF current ratio and leakage current.Using Si as the channel material limits the property to reduce leakage current with scaling of channel,whereas the AlxGalxAs based DG tunnel FET provides a better ION/IoFF current ratio (2.51 × 106) as compared to other devices keeping the leakage current within permissible limits.The performed silmulation of the CNT based channel in the double-gate tunnel field-effect transistor using the nano ViDES shows better performace for a sub-threshold slope of 29.4 mV/dec as the channel is scaled down.The proposed work shows the potential of the CNT channel based DG tunnel FET as a futuristic device for better switching and high retention time,which makes it suitable for memory based circuits.     

TD-SCDMA标准的CDMA/TDMA改革方案

文章证明了TD-SCDMA标准所定义的智能天线在TD-SCDMA标准中的不可用性,因此必须对该标准进行大规模改造。文章给出一种在上/下行信道分别使用码分多址/时分多址(CDMA/TDMA)的TD-SCDMA标准的改革方案。该方案在下行信道中可以继续使用TD-SCDMA标准所定义的智能天线,使中国唯一具有自主知识产权的移动通信标准获得新生。在下行信道中还可以使用八相相移键控(8PSK)、16进制正交调幅(16QAM)等高频谱利用率的调制方法,能将富裕的下行功率变换为频谱利用率。改革后的TD-SCDMA标准将能满足移动因特网的应用要求。     

聚乙烯阻燃光缆护套料的制备工艺研究

在低密度聚乙烯(PE)中添加了纳米氢氧化镁(Mg(OH2))和磷酸三苯酯(TPP)组成的协同阻燃剂,采用共混挤出的方法制备了纳米Mg(OH2)/PE阻燃光缆护套料.对制得的样品进行了氧指数(OI)、示差扫描量热(DSC)法和力学性能的测试,实验结果表明,样品的OI大幅度提高,力学性能和玻璃化温度均满足阻燃光缆护套的要求.     

Interfacial reaction and shear strength of SnAgCu-xNi/Ni solder joints during aging at 150 °C

The interfacial microstructure and shear strength of Sn3.8Ag0.7Cu-xNi (SAC-xNi, x = 0.5, 1, and 2) composite solders on Ni/Au finished Cu pads were investigated in detail after aging at 150 °C for up to 1000 h. The interfacial characteristics of composite solder joints were affected significantly by the weight percentages of added Ni micro-particles and aging time. After aging for 200 h, the solder joints of SAC, SAC-0.5Ni and -1Ni presented duplex intermetallic compound (IMC) layers regardless of the initial interfacial structure on as-reflowed joints, whose upper and lower IMC layers were comprised of (CuNi)₆Sn₅ and (NiCu)₃Sn₄, respectively. Only a single (NiCu)₃Sn₄ IMC layer was ever observed at the SAC-2Ni/Ni interface on whole aging process. Based on the compositional analysis, the amount of Ni within the IMC regions increased as the proportion of Ni addition increased. The IMC (NiCu)₃Sn₄ layer thickness on the interface of SAC and SAC-0.5Ni grew more slowly when compared to that of SAC-1Ni and -2Ni, while for the (CuNi)₆Sn₅ layer the reverse is true. Except the IMCs sizes are increased with increased aging time, the interfacial IMCs tended to transfer their morphologies to polyhedra. In all composite joints testing, the shear strengths were approximately equal to non-composite joints. The fracturing observed during shear testing of composite joints occurred in the bulk solder, indicating that the SAC-xNi/Ni solder joints had a desirable joint reliability.     

有机发光二极管中ADN掺杂ErQ的1.54μm电致发光

自行设计了基于8-羟基喹啉铒(ErQ)为发射层(EMLs)和二硝酰胺铵(ADN)为蓝光主体材料的近红外有机发光二级管.器件的基本结构为(p-Si/NPB/EML/Bphen/Bphen:Cs2CO3/Sm/Au),设计并比较了三套不同发射层结构(ErQ/ADN为双层结构器件,(ErQ/ADN)×3为多层结构器件,ErQ:ADN为掺杂结构器件)的器件.三组器件在一定的偏压下,均可发出1.54μm的光,对应三价铒离子4I13/2→4I15/2的跃迁.其中,ADN:ErQ(1∶1)掺杂结构的近红外电致发光强度是ADN/ErQ双层结构中的三倍.此外,不同掺杂浓度的ADN:ErQ复合膜做了以下表征:吸收谱、光致发光谱和荧光寿命谱.实验结果证实了在近红外电致发光过程中存在从ADN主体分子到ErQ发射分子的高效率的能量转移.     

Emerging interconnects: a state-of-the-art review and emerging solutions

Aluminium was a primary material for interconnection in integrated circuits (ICs) since their inception. Later, copper was introduced as interconnect material which has better metallic conductivity and resistance to electromigration. As the aggressive technology scaling continues, the copper resistivity increased because of size effects, which causes increase in delay, power dissipation and electromigration. The need to reduce the resistor-capacitor??????? delay, dynamic power utilisation and the crosstalk commotion is as of now the fundamental main impetus behind the presentation of new materials. The purpose of this paper is to do a survey of interconnect material used in IC from introduction of ICs to till date. This paper studies and reviews new materials available for interconnect application which are optical interconnects, carbon nanotube (CNT), graphene nanoribbons (GNRs) and silicon nanowires which are alternatives to copper. While doing a survey of interconnect material, it is found that multiwalled CNTs, multilayer GNR and mixed CNT bundles are promising candidates and are ultimate choice that can strongly address the problems faced by copper but on integration basis copper would last for coming years.     

聚对苯撑苯并双(口恶)唑发光及其器件制备

采用光谱技术,研究了聚对苯撑苯并双(口恶)唑(PBO)溶液的光敏发光特性,并用相对法估算出溶液发光效率在50%范围.结合光谱技术、半导体电学和电化学等研究手段,具体研究了以PBO为发光层的单层电致发光器件,研究结果显示,电致发光与薄膜的光致发光有具有相同的发光中心,峰值位于510 nm左右.同时发现,由于存制备过程中不同处理条件使得不同厚度薄膜残留的掺杂物质浓度不同,从而引起薄膜的导电性的不同.使得器件的阈值场强随PBO厚度的减小而逐渐增加.     

人小肠粘膜免疫酶的定位研究—光镜和电镜免疫组织化学染色法

本文对免疫酶组织化学的样品制备程序和染色方法做了详细的阐述。用直接法、间接法和ABC法,对人小肠免疫酶的定位,进行了光镜和电镜的观察,染色阳性反应显著,获得了满意的效果。并对染色技巧做了分析和探讨。     

BNBST无铅压电陶瓷的制备工艺研究

设计了（Bi0.55Na0.5）1-X（BaaSrb）xTiO3（BNBST[100x-100a／100b]）无铅压电陶瓷新体系。该体系压电陶瓷具有工艺特性及压电响应好，压电常数高的特点，且有实际应用前景的新型压电陶瓷材料体系。采用传统的陶瓷工艺制备了（Bi0.55Na0.5）1-X（BaaSrb）xTiO3无铅压电陶瓷，研究了制备工艺参数对其物化结构性能的影响。生料的热重-差热（TGA-DTA）分析表明，粉料合成过程中，先是SrTiO3、BaTiO3的形成，然后是（Bi0．5Na0．5）Tio，的形成，同时三者形成固溶体；密度测试表明，陶瓷的体积密度随烧结温度的升高而增大，可较易获得理论密度94％的陶瓷；X-射线能谱分析（EDAX）研究表明，陶瓷的Bi、Na的挥发随着烧结温度的升高而加剧。研究结果表明，要制备性能优良的无铅压电陶瓷，需要精确控制制备工艺。     

钠离子对poly(dT).poly(dA).poly(dT)三螺旋DNA分子呼吸模式的影响

利用分子结构的螺旋对称性,建立了一个包括钠离子的三链DNA分子poly(dT)*poly(dA)*poly(dT)的晶格动力学模型,计算了poly(dT)*poly(dA)*poly(dT)的氢键呼吸模式.结果发现钠离子的加入明显地淬灭了位于较低频率的几个最为强烈的Hoogensteen氢键呼吸模式,而对Watson-Crick氢键呼吸模式影响不明显,这说明钠离子能提高poly(dT)*poly(dA)*poly(dT)三螺旋结构的稳定性.该计算结果很好地解释了poly(dT)*poly(dA)*poly(dT)的热融化实验.     

Arsenic deposition as a precursor layer on silicon (211) and (311) surfaces

We investigate the properties of arsenic (As) covered Si(211) and Si(311) surfaces by analyzing data from x-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED) images. We then create a model using total surface energy calculations. It was found that both Si(211) and Si(311) had 0.68±0.08 surface As coverage. Si(211) had 0.28±0.04 Te coverage and Si(311) had 0.24±0.04 Te coverage. The Si(211) surface replaces the terrace and trench Si atoms with As for a lower surface energy, while the Si edge atoms form dimers. The Si(311) surface replaces all terrace atoms and adsorbs an As dimer every other edge site. These configurations imply an improvement in the mean migration path from the bare silicon surface by allowing the impinging atoms for the next epitaxial layer, tellurium (Te), to bind at every other pair of edge atoms, and not the step terrace sites. This would ensure a nonpolar, B-face growth.     

系统级封装新型埋入式电源滤波结构的研究

在高密度小尺寸的系统级封装(SiP)中,对供电系统的完整性要求越来越高,多芯片共用一个电源网路所产生的电压抖动除了会影响到芯片的正常工作,还会通过供电网路干扰到临近电路和其他敏感电路,导致芯片误动作,以及信号完整性和其他电磁干扰问题.这种电压抖动所占频带相当宽,几百MHz到几个GHz的中频电源噪声普通方法很难去除.结合埋入式电容和电源分割方法的特点,提出一种新型高性能埋入式电源低通滤波结构直接替代电源/地平面.研究表明,在0.65～4GHz的频带内隔离深度可达-40～75 dB,电源阻抗均在0.25ohm以下,实现了宽频高隔离度的高性能滤波作用.分别用电磁场和广义传输线两种仿真器模拟,高频等效电路模型分析这种低通滤波器的工作原理以及结构对隔离性能的影响,并进行了实验验证.     

Joint estimation of TOA and DOA in IR-UWB system using a successive propagator method

Impulse radio ultra-wideband (IR-UWB) ranging and positioning require accurate estimation of time-of-arrival (TOA) and direction-of-arrival (DOA). With receiver of two antennas, both of the TOA and DOA parameters can be estimated via two-dimensional (2D) propagator method (PM), in which the 2D spectral peak searching, however, renders much higher computational complexity. This paper proposes a successive PM algorithm for joint TOA and DOA estimation in IR-UWB system to avoid 2D spectral peak searching. The proposed algorithm firstly gets the initial TOA estimates in the two antennas from the propagation matrix, then utilises successively one-dimensional (1D) local searches to achieve the estimation of TOAs in the two antennas, and finally obtains the DOA estimates via the difference in the TOAs between the two antennas. The proposed algorithm, which only requires 1D local searches, can avoid the high computational cost in 2D-PM algorithm. Furthermore, the proposed algorithm can obtain automatically paired parameters and has better joint TOA and DOA estimation performance than conventional PM algorithm, estimation of signal parameters via rotational invariance techniques algorithm and matrix pencil algorithm. Meanwhile, it has very close parameter estimation to that of 2D-PM algorithm. We have also derived the mean square error of TOA and DOA estimation of the proposed algorithm and the Cramer-Rao bound of TOA and DOA estimation in this paper. The simulation results verify the usefulness of the proposed algorithm.