10Gbit/s高速串行通道的Hspice仿真研究

随着光传输技术的飞速发展,信号传输速率已经突破Gbit/s级,高速通道的仿真分析已成为系统开发成功与否的关键一环.文章简要介绍了Hspice仿真的基本原理和基本方法,并详细讨论了基于Hspice软件的高速串行通道仿真方法,通过仿真眼图的对比结果说明影响高速通道性能的几个关键环节以及改善通道特性的方法.     

电子产品的故障分析技术

文中简单介绍电子产品的故障分析技术,着重介绍如何开展故障分析,以确保故障信息的正确性和完整性,达到改进产品质量的目的。     

半圆形半导体激光器阵列准直工艺方法研究

通过试验,分析并验证了半圆形半导体激光器阵列准直后光束指向发生偏移的原因,证明了烧结过程对准直光束指向性的影响。为避免烧结过程对准直工艺的影响,设计了一种的新的半圆形半导体激光器阵列的准直工艺方法,并设计了半圆形半导体激光器阵列准直工艺平台,实现了对半圆形半导体激光器在组装、烧结后进行阵列准直;同时采用两点一线的原理,设计了用于半圆形半导体激光器阵列准直的双屏监测方法,有效提高了准直的指向准确性和工作效率。通过一对半圆形器件对Ф3mm的固体棒进行泵浦试验,工艺改进后的泵浦增益有了明显提高,泵浦功率为2.3kW时,增益提高了大约15%。     

Mg掺杂AlGaN的特性研究

采用金属有机物化学气相淀积方法在Al2O3衬底上生长不同浓度Mg掺杂的AlxGa1-xN合金薄膜,并在750℃、N2气氛下对Mg进行热退火激活。用X射线衍射ω-2θ扫描计算确定样品的Al组分,发现Mg摩尔掺杂浓度和退火对Al组分均未产生明显影响。X射线衍射摇摆曲线与原子力显微镜扫描表明随Mg摩尔掺杂浓度增加,样品晶体质量下降,样品表面凹坑增加,但热退火对薄膜表面形貌有明显的改善。阴极射线发光测量发现带边峰强度随掺杂浓度增加而减弱,退火后样品的施主-受主对复合发射与导带受主的复合发射均有增强,验证了热退火对钝化受主杂质的激活作用,对实现高效AlGaN的p型掺杂具有重要意义。     

SLED中熔锥形透镜光纤耦合设计

文章提出一种熔锥形透镜光纤的设计方法,与常用的圆锥形保偏单模光纤相比,熔锥形透镜光纤与超辐射发光二极管(SLED)管芯的耦合效率可由原来的45%提高到60%,工作距离由7 μm达到超过15 μm,且前者的耦合容差远远大于后者.对于新设计的熔锥形透镜光纤,文章还给出了偏移和偏心与耦合效率的关系曲线图.     

Demodulated method of optical fiber stokes temperature sensors

The optical fiber temperature sensoris one of the dis-tributed measurement apparatus applied to the smartstructures of civil and military engineering.In the dis-tributedfiber Ramantemperature sensor ,the anti-Stokesand Stokes scattering radiation is sensi…     

Design and frequency/phase-noise analysis of a 10-GHz CMOS ring oscillator with coarse and fine frequency tuning

A 10-GHz CMOS ring oscillator that employs a multi-pass technique for boosting its frequency is proposed in this paper. The proposed circuit allows the tuning gain to be lowered by deploying the coarse/fine frequency tuning whilst maintaining wide frequency coverage. The small signal model of the proposed delay stage and the circuit operation are discussed in this paper. The time-variant analysis presented permits accurate prediction of the frequency tuning characteristic and the results have been verified by simulation. The phase noise analysis is also discussed in detail to provide better insight to the noise that is contributed by each transistor. The calculated results agreed well with that of the simulations. Hai Qi Liu was born in Jiangsu, China, in 1979. He received the B.S. and M.Sc. degrees, both in electrical engineering from the Tianjin University, Tianjin, China, in 2000, and Tongji University, Shanghai, China, in 2003, respectively. He is currently working toward the Ph.D. degree at the Nanyang Technological University, Singapore. His research focuses mainly on the design of fully integrated oscillators and Phase-Locked Loops for optical communication applications. His research interests also include RF frequency synthesizers and RF front-end designs for wireless applications. Wang Ling Goh obtained both her B.Eng and Ph.D. degrees from the department of Electrical and Electronic Engineering at the Queen’s University of Belfast (QUB) in United Kingdom. When working on her Ph.D., she was also engaged as a research associate at the Northern Ireland Semiconductor Research Centre (NISRC) at QUB. Dr Goh joined the School of Electrical and Electronic Engineering at the Nanyang Technological University (NTU) in Singapore as a lecturer in January 1996. She is now an Associate Professor in the Division of Circuits and Systems, School of Electrical & Electronic Engineering. Dr Goh has to-date co-authored 1 book, filed 13 patents (granted), and published about 60 research papers in international conferences and journals. Her research interests are in areas of silicon device processing technologies as well as digital and mixed-signal IC designs. Liter Siek received the B.A.Sc. degree from University of Ottawa, Ontario, Canada; the M.Eng.Sc. from University of New South Wales, Sydney, Australia; and the Ph.D. from Nanyang Technological University, Singapore. From 1981 to 1983 he was employed in several companies in the area of automation and control. From 1983 to 1985, he was with SGS, currently known as ST Microelectronics situated in Castelletto, Milan, Italy, where he worked in the central R&D Laboratories for Linear IC. From 1985 to 1987, he was with the same company situated in Singapore’s Asia Pacific Design Center. Since October 1988, he has been with Nanyang Technological University. His research interests are in the design of bipolar, CMOS and BiCMOS analog/mixed signal ICs. In addition, he has authored and co-authored 53 international journal/conference technical papers.     

几种TCP协议下F、G函数的研究

随着网络技术的不断提高,一些新型的高速网络投入使用,产生了一系列如TCP拥塞控制算法,其中Reno协议、Vegas协议、RED协议以不同的方式解决了网络拥塞的问题。通过在以上3种协议模型下对F、G函数进行推导,用对偶方程求解的方法,比较3种协议的优劣,为网络模型的建立打下基础。     

云台山地质的激光诱导击穿光谱研究

利用高能量Nd:YAG脉冲激光器1064nm光束聚焦待测样品表面产生等离子体,并用光谱仪和ICCD来探测其光谱信号.采用激光击穿光谱(LIBS)技术对云台山的泉水、岩石和土壤进行了定性研究.对比分析泉水和纯净水的光谱图,得出泉水中含有Ca和Mg元素.通过比较茱萸峰岩石和潭瀑峡岩石的实验结果,可知两种岩石的成分存在较大差异,潭瀑峡岩石所含成分相对较多.同时还对云台山茱萸峰土壤和中南民族大学附近的土壤进行了对比分析,发现中南民族大学电信学院附近的土壤中含有Zn、Cu、Hg,而在茱萸峰的土壤中发现一种植物生长必需的微量矿质元素Ni.     

High‐Performance Organic Transistor Memory Elements with Steep Flanks of Hysteresis

High‐performance organic transistor memory elements with donor‐polymer blends as buffer layers are presented. These organic memory transistors have steep flanks of hysteresis with an ON/OFF memory ratio of up to 2 × 10⁴, and a retention time in excess of 24 h. Inexpensive materials such as poly(methyl methacrylate), ferrocene and copper phthalocyanine are used for the device fabrication, providing a convenient approach of producing organic memory transistors at low cost and high efficiency.