一种小型化移动终端全网通天线

提出一款适用于移动终端设备的小型化全网通天线, 天线由参考地和平面天线构成, 采用同轴馈电.该天线的高频通带响应通过高频单元基模与低频单元分支的高次模实现, 天线的低频通带响应通过低频单元基模实现, 并采用展宽低频单元枝节的方法实现所需低频通带带宽.天线总尺寸为30 mm×67 mm, 其中辐射单元为33 mm×30 mm, 参考地大小为34 mm×30 mm.使用微波仿真软件HFSS对天线的尺寸进行了设计优化, 并对回波损耗、天线表面电流和天线的辐射方向图进行研究.天线样品的实测-6 dB阻抗带宽为820~968 MHz, 1 695 ~3 020 MHz, 覆盖了工信部所颁布的国内移动通信运营商所用的2G、3G、4G网络的全部频段.天线结构简单、覆盖频率广、体积小, 具有一定的工程应用价值.     

共面波导馈电的WLAN和WiMAX小型化三频段天线设计

本文给出了一款小型化多频段平面印刷单极子天线的设计和分析过程.该天线由一个矩形主辐射贴片和两个附属辐射枝节组成.主辐射贴片和两个附属枝节分别产生三个通带覆盖2.4/5.2/5.8GHz的WLAN工作频段和2.5/3.5/5.5GHz的WiMAX工作频段.天线的仿真结果表明,在WLAN频段以及WiMAX频段天线具有良好的阻抗带宽和辐射效率,天线的总尺寸为20mm×30mm×1.6 mm,结构紧凑,易于制作,适用于WLAN和WiMAX系统.     

超小型设备上的双频带天线设计

研究了一种超小型设备上的双频带天线.该超小型设备的尺寸为30mm×30mm×15mm,其最大边长不到低频所对应波长的十分之一.通过在低频激励地板辐射,在高频激励天线单元辐射的方案,实现了双谐振.同时还采用立体折叠地面方案进一步改进天线的低频性能.结合使用匹配电路,最终实现了GSM900(880～960MHz)和GSMl800(1710～1880 MHz)双频带覆盖.在仿真设计的基础上实际制作了原型天线并进行测量,仿真和测试结果吻合良好.     

一种新型三频天线的设计与分析

设计了一种新型的基于多枝节结构的三频天线。该天线由共面波导馈电,天线整体尺寸为30 mm×35mm×1.5 mm,基板选用FR4,其相对介电常数为4.4。天线由三个贴片构成,通过调整三个贴片的长宽,可以使得三个贴片产生低频到高频三个中心频点,从而形成了三个工作频段。天线通过在贴片和共面波导的地平面中加入渐变结构,改善了三个频段上的阻抗匹配。采用仿真软件HFSS对天线进行了分析和优化。仿真结果表明,天线的–10d B工作频段分别为:2.33~2.75 GHz,3.15~3.75 GHz,4.35~6.07 GHz,能够较好地覆盖WLAN和Wi MAX的通信频段。天线的结构简单,尺寸较小,具有较好的辐射特性。     

一种宽带多网组合卫星导航终端天线

为了满足多系统兼容、高集成度卫星定位终端对天线的需求,提出了一种宽带多网组合卫星导航终端天线。天线采用宽带交叉偶极子结构实现全球卫星导航系统全频段(1 164 MHz～1 278 MHz&1 557 MHz～1 612 MHz)覆盖,采用平面倒F天线结构实现蓝牙/WLAN频段(2 400 MHz～2 483.5 MHz)覆盖,采用缺陷地单极子结构实现移动通信宽频(824 MHz～960 MHz&1 710 MHz～2 690 MHz)覆盖,通过微带枝节匹配和去耦结构等手段实现多组天线的融合,天线整体尺寸为120 mm×120 mm×45 mm。实测结果表明：天线电压驻波比优于目标带宽,方向图增益实测结果与仿真结果吻合。该天线具有频带宽、增益高、易调谐等优点,可较好地应用于全频段全网通测量型卫星定位终端设备中。     

小型化窄条形宽带柔性天线

设计了一款小型化窄条形宽带柔性天线,该天线由辐射片和带有短路枝节的共面波导金属地构成,整体尺寸为24.5 mm×5.0 mm×0.1 mm。通过采用带有短路枝节的共面波导金属地、新共面波导结构、两个U型缝隙、馈线倾斜焊接等方法,有效增加了阻抗带宽,且与常规柔性天线相比尺寸减小70%。测试结果表明,天线用于超宽带定位系统中的智能手表时,工作频段覆盖3.27～4.55 GHz,带宽内增益大于2.4 dBi,不圆度小于0.95 dB。     

应用于蓝牙/TD-LTE/WiMAX的多频段平面天线

提出了一种具有新颖缺陷地结构的多频段新型平面天线,该天线采用微带馈电方式进行馈电,改进的接地板通过延伸两段倒T字形枝节,得到了蓝牙、TD-LTE和X波段卫星通信频段;Wi MAX通信频段则通过左右对称的倒钩形结构辐射贴片获得。该天线实际测量带宽为2.42~2.78 GHz、3.02~3.62 GHz和7.25~7.88 GHz,能完整覆盖蓝牙、TD-LTE、Wi MAX和X波段卫星通信下行频段,尺寸为20 mm×30 mm。天线结构简单、尺寸小及全向性辐射特性表明该天线能很好地满足便携式多频段移动设备的需求。     

一种集总元件加载极端电小折叠单极子天线设计

针对无线通信等领域对电小天线的应用需求，设计了一种基于加载集总元件技术的极端电小折叠单极子天线结构。该天线在平面单极子天线的基础上，增加短路枝节拓展电流路径扩展带宽，采用集总元件加载技术，在辐射贴片上串联电阻元件增加输入电阻，并联电抗元件以改善输入电抗，实现了天线的极端电小特性。仿真表明，这种结构可以达到0.053λ×0.022λ×0.000 8λ(94 mm×40 mm×1.5 mm,λ为低频170 MHz处的波长)的极端电小尺寸，电压驻波比(Voltage Standing Wave Ratio, VSWR)在170～910 MHz时小于2,具有超宽带特性，并在工作频带内天线都具有良好的全向辐射特性。仿真分析了350 MHz、550 MHz、750 MHz三个频点处的方向图，且对应增益分别能达到-28.8 dBi、-16.7 dBi、-10.4 dBi。加工制作了该极端电小天线模型，实验测试验证了该天线的电小特性和超宽带特性，且方向图和增益测试结果均与仿真结果吻合良好。     

背面寄生单元形成双陷波超宽带天线

提出并制作了能避免来自WLAN和X波段卫星通信系统干扰,具有双陷波特性的超宽带天线.该天线印制在介电常数为4.4的FR4材料上,整个天线的尺寸为22 mm×31 mm×1.6 mm.通过在辐射贴片背面和地面之间添加由L形结构结合调谐枝节形成的新颖背面寄生单元使天线具有两个陷波.该设计使用HFSS软件仿真,仿真与测试结果表明所提出天线结构实现了双陷波功能.     

应用于无线USB的小型超宽带阻带天线

设计了一种用于超宽带无线通信系统的小型化天线.该天线贴片尺寸为20 mm×15 mm×3mm,采用U形折叠结构和渐变结构相结合,可使天线具有超宽带特性.为了减小对无线局域网(WLAN)系统5GHz频带的干扰,天线采取了叉形谐振结构来实现对相应频带的抑制.采用仿真软件分析了该天线阻抗带宽和不同频点处的辐射方向图.仿真和实...     

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.