恒带宽窄带集总跳频滤波器的理论计算与实现

为了快速准确地设计并制作恒带宽窄带集总跳频滤波器,提出了一种随频率变化而变化的负载结构.通过对这种结构模型的分析,得到了其关于频率和相对带宽的精确变换公式,利用麦夸特优化法对其进行优化计算,快速得到该负载结构各部件的最优值.最后利用该方法设计并制作了一个二阶集总带通滤波器.实验结果表明,该方法实现滤波器比传统手调快几倍...     

基于有向超图的工作流资源分配均衡优化方法

为了拓展工作流资源分配均衡优化的深度和广度,提出了一种考虑过程支持资源变化与过程结构变化相互影响的优化方法.通过对过程进行扩展超图建模,利用超图的性质以及活动能力需求集与支持资源能力集之间的耦合,给出了过程结构随支持资源变化而变化的形式化处理规则;给出了由不同结构过程构成的、用于工作流资源分配均衡优化超图模型(DHM-WRAB)的建模规则,使工作流资源分配均衡优化转化为具有权因子的超图最短路径求解问题,并给出求解过程;最后,通过举例证明该方法可行、有效.     

双层EBG结构的优化设计

研究了一种新型的双层电磁带隙(EBG)结构,该结构在金属导带上刻蚀蝶形单元,在接地板上刻蚀圆环孔,并运用粒子群优化算法(PSO)与高频电磁仿真软件(HFSS)相结合的方法对接地板刻蚀圆孔进行优化,使结构的传输特性更好.在优化过程中,首先对圆孔的外径进行优化,然后在此基础上再优化内径,通过仿真计算结果可看出,优化后-10 dB的相对带宽和阻带的衰减值分别增加了22.69％和15.26％,通带波纹减小了76.76％.优化后结构的频率特性较好,优化效果理想.     

一种基于Kriging模型和受限差分进化的电磁结构快速优化算法

进化算法在各类电磁结构优化设计中有着广泛的应用，但由于需要在参数空间中进行随机搜索并仿真试探，优化效率普遍较低.针对这一问题，提出受限差分进化（Differential Evolution，DE）算法与Kriging代理模型相结合的电磁结构快速优化算法.算法根据参考设计结果建立圆柱管道空间，通过参数变换将进化区域限制在管道内部.Kriging模型学习管道内样本及其仿真数据，代替电磁仿真快速预测进化产生下一代种群的响应.相比整个参数空间，该算法DE寻优和Kriging学习的区域被显著减小，优化效率得到提升.通过一个波导双孔定向耦合器的优化设计，表明该方法的求解质量和收敛速度优于现有算法.     

△∑调制器在分数分频频率综合器中的分析与设计

提出了一种适用于分数分频锁相环频率综合器的全数字噪声整型△∑调制器电路结构新的设计方法,并将其最终实现.采用了流水线技术和新的CST算法优化多位输入加法器结构,从而降低了整体的复杂度和功耗.这种电路结构通过了Matlab的行为级仿真,ASIC全定制实现并流片,该结构也通过VHDL综合实现验证,最后给出的测试结果表明该电路具有良好的性能,可应用于单片千兆赫兹级低功耗CMOS频率综合器中.     

Analysis and Design of a ΔΣ Modulator for Fractional-N Frequency Synthesis

提出了一种适用于分数分频锁相环频率综合器的全数字噪声整型 ΔΣ调制器电路结构新的设计方法,并将其最终实现. 采用了流水线技术和新的CST算法优化多位输入加法器结构，从而降低了整体的复杂度和功耗. 这种电路结构通过了Matlab的行为级仿真，ASIC全定制实现并流片，该结构也通过VHDL综合实现验证，最后给出的测试结果表明该电路具有良好的性能，可应用于单片千兆赫兹级低功耗CMOS频率综合器中.     

ΔΣ调制器在分数分频频率综合器中的分析与设计(英文)

提出了一种适用于分数分频锁相环频率综合器的全数字噪声整型ΔΣ调制器电路结构新的设计方法,并将其最终实现.采用了流水线技术和新的CST算法优化多位输入加法器结构,从而降低了整体的复杂度和功耗.这种电路结构通过了Matlab的行为级仿真,ASIC全定制实现并流片,该结构也通过VHDL综合实现验证,最后给出的测试结果表明该电路具有良好的性能,可应用于单片千兆赫兹级低功耗CMOS频率综合器中.     

△∑调制器在分数分频频率综合器中的分析与设计

提出了一种适用于分数分频锁相环频率综合器的全数字噪声整型△∑调制器电路结构新的设计方法,并将其最终实现.采用了流水线技术和新的CST算法优化多位输入加法器结构,从而降低了整体的复杂度和功耗.这种电路结构通过了Matlab的行为级仿真,ASIC全定制实现并流片,该结构也通过VHDL综合实现验证,最后给出的测试结果表明该电路具有良好的性能,可应用于单片千兆赫兹级低功耗CMOS频率综合器中.     

MEMS压阻超声传感器的设计与优化

提出了一种新的压阻式超声传感器结构,该结构由主振梁和微传感梁组成,在声压的作用下,主振梁振动从而带动微传感梁的振动.通过有限元软件Ansys仿真分析该结构的灵敏度,并与悬臂梁结构压阻式声传感器相比,结果表明灵敏度有了一定的提高.为了实现结构的优化,仿真了结构的尺寸与共振频率的关系,对相同共振频率的结构进行了静力分析,计算并对比了不同尺寸结构的灵敏度,从而得到灵敏度最高的结构,实现了结构的优化.     

基于差集与遗传算法的同心圆阵稀疏优化方法

同心圆阵天线具有结构简单、波束旋转对称、旁瓣电平低等特点,但是阵列阵元数较多,系统实现的代价大.文中提出了一种非均匀稀疏同心圆阵的设计方法.基于差集的阵列稀疏优化方法具有解析性,运算量小,旁瓣电平低等优点.首先利用循环差集方法获得阵列初始的稀疏优化结构,并进一步将差集产生的解集作为遗传算法的初始值,通过差集与遗传算法相结合进一步优化阵列结构.仿真结果表明:该方法在保持较大稀疏率的同时获得了较理想的旁瓣电平.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.