C波段小型化低相噪全相参频率综合器

提出了一种小型低相噪、低杂散的C波段全相参频率综合器设计方案。基带信号由DDS芯片产生,通过对环路滤波器和电路印制板的优化设计改善相噪和杂散性能,并与PLL输出的C波段点频信号进行上变频,得到所需信号。介绍了实现原理、相位噪声模型及设计方法。测试结果表明,在7.8GHz处,频综相位噪声≤-103dBc/Hz@100kHz,杂波抑制≤-61dBc。     

X频段高频谱纯度频率合成器设计

针对高灵敏度接收机对频率合成器的高技术指标要求,构建了一种融合了直接模拟、直接数字以及间接数字的频率合成技术方案,根据该方案,成功实现了频率合成器的工程研制。通过测试,频率合成器相位噪声达-112 dBc/Hz@5 kHz,杂散抑制优于-75 dBc,频率分辨率小于1 kHz,10 MHz跳频时间约为13 μs,满足了高灵敏度接收机对频率合成器的高技术指标要求,为高纯度频率合成器的实现提供了一条新途径。     

一种超宽带捷变频源的研制

本文介绍了一种超宽带捷变频源的设计与实现过程，该频率源采用直接模拟合成方式，通过合理的频率划分和高性能的开关滤波组件技术实现了超宽带、捷变频、低相噪、低杂散的优异性能，并给出了最终测试结果。实测结果表明该频率源在 Ku 波段 6GHz 带宽范围内具有杂散抑制优于-70dBc，相位噪声优于-103dBc/Hz@1kHz，跳频时间小于 200ns 等的性能。     

一种S波段跳频源的设计

为了某项目设计一款频率在2-3GHz宽带跳频源,频率间隔为1MHz,跳频点数为1001点。该跳频源要求相位噪声小于-100dBc @1kHz,杂散优于60dB。分析指标和软件仿真计算,采用HITTITE公司的HMC830锁相芯片来实现该设计方案。采用HITTITE公司的PLL仿真设计软件对环路滤波器进行优化设计后应用到实际电路中,使得该芯片在-55℃到+85℃均可稳定工作。通过外接串口通信控制模块,实现频率的跳变。最终该设计的实物测试相位噪声、杂散指标均优于目标值。测试得到该频率源相位噪声可达到-100dBc/Hz@1kHz,杂散指标能够达到-70dB,具有工程应用价值     

深空测控系统1 Hz低相噪频率合成技术

针对深空测控系统高精度测量对于信道附加相噪的要求,采用直接数字频率合成（DDS）正交调制方法设计频率综合器。通过巧妙的试验和外推方法,择优选取电压型鉴相器,在锁相环相噪模型的基础上,全面分析各部分相噪的贡献,综合设计环路带宽,有效控制附加相噪,实现低相噪频综器最理想的目标,即环路带内的相噪完全由参考决定,带外的相噪由压控振荡器（VCO）决定,并采用两源互比的方法完成1 Hz极低相位噪声的测试,测试结果为-73 dBc/Hz,与设计结果完全一致。该方法对于测控站极低相噪的设计具有一定参考价值。     

基于DDS与PLL的C波段全相参雷达频综设计

提出了一种直接数字频率合成(DDS)与锁相环(PLL)相结合的全相参频率合成方案。运用HMC704控制压控振荡器(VCO)设计高性能锁相本振源,将AD9910在基带产生的线性调频(LFM)脉冲调制信号经二次变频搬移到C波段,改善了输出信号的相噪和杂散,降低了系统的复杂性。实现了低相噪,低杂散,窄步进的C波段全相参雷达频综。结果表明,该频综在C波段输出LFM信号的幅度大于10dBm,频率步进为1kHz,相位噪声优于-103dBc/Hz@1kHz,各项指标均满足实际工程要求。     

X波段锁相混频频率合成器设计

提出了一种低相噪、低杂散的X波段捷变频频合器的设计方案.首先利用P波段数字锁相环产生跳频基准信号,并通过精心选择器件和优化设计环路滤波器改善相噪和杂散性能,再与X波段频标信号上变频,产生所需信号.测试结果为相位噪声≤-91 dBc/Hz@10 kHz,杂波抑制≤-72 dBc,捷变频时间≤90μs.     

高频谱纯度小步进频率合成器的设计与实现

讨论了一种杂散抑制高,频率步进小及相位噪声低的频率合成器的设计方法。设计采用混合式频率合成技术,研制实现了S波段频率合成器,实验结果表明,该频率合成器输出信号频率步进100 Hz,相位噪声优于-115dBc/Hz@10kHz,杂散抑制大于80dBc,跳频时间140μs。     

DDS激励PLL高性能频率合成器设计

为适用CDMA各类收发机的射频本振的应用要求,研制了一种低杂散低相噪高分辨率的P波段频率合成器。利用DDS输出信号具有高分辨率和PLL具有窄带跟踪滤波特性,通过有效的频率规划和参数配置,规避了DDS由于相位截断近端杂散无法消除的缺陷,有效抑制了DDS中DAC非线性和幅度量化误差引起的宽带杂散。通过仿真分析了方案的可行性,设计了样品并进行了测试。结果显示,所设计的频率合成器输出频率范围为755～765MHz,频率分辨率为100.5 kHz,杂散优于-71 dBc,相位噪声优于-105 dBc/Hz@1 kHz。     

低相噪捷变频毫米波频率源的研制

基于整数和小数分频锁相原理,采用双锁相源+混频方案,实现了一种可用于毫米波雷达系统的低相噪、小步进、捷变频毫米波频率源。实测结果表明:该频率源产品在31.0~32.5GHz频带范围内,相位噪声可达-90dBc/Hz@1kHz,跳频时间小于10μs,跳频步进100kHz,最低杂散抑制低于-60dBc。     

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.