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。     

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。     

L波段细步进捷变频频率综合器设计

介绍一种模块化的L波段细步进捷变频频率综合器,采用直接数字频率合成器实现细步进,采用上变频器＋倍频器来提高并扩展带宽。讨论其频率规划及功能模块划分,论述了关键指标设计、分析及实现,最后给出了测试结果。该方法可以在实现100Hz细步进的同时,杂散抑制大于65dBc,跳频时间小于1μs。     

超宽带频率合成器的设计与实现

通过采用直接数字与直接模拟相结合的混合合成方案,实现了1～18 GHz超宽带、10 Hz小步进输出,跳频时间小于1 μs.并达到了杂散优于-50dBc、相噪优于-90dBc/Hz偏离载频1kHz处的技术要求.     

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     

Ka 波段应用的捷变频高频率分辨率频率合成器

传统基于锁相环(PLL)实现带宽信号输出的频率合成方案,常常为了获得高输出频率而降低频率分辨率和缩短跳频时间。相较而言,基于直接数字频率合成器(DDS)实现带宽信号输出的频率合成方案,其频率分辨率更高,跳频时间更快。然而,DDS 输出频率低,须经多次混频或倍频操作以提升输出频率,对频率源中的滤波器设计造成极大压力,并且这种压力随着频率源输出频率的升高而不断上升。对此,基于高性能、小型化无源滤波器的设计能力,实现了基于DDS 变频的34-35GHz 捷变频、高频率分辨率频率源。实验结果表明,其工作相位噪声优于-85dBc/Hz@1kHz,杂散和谐波抑制优于45 dBc,频率分辨率达到1.86Hz,跳频时间最快4ns。     

C波段宽带高速跳频频率源的设计与实现

针对高速跳频通信系统的需求,设计并实现了一款工作在C波段、带宽为1 GHz、步进为3 MHz的宽带频率源。该频率源采用DDS激励PLL方案,用FPGA控制DDS实现低频段的小步进跳频,再用乒乓式锁相环进行倍频得到最终输出。采用2路DDS基准时钟来保证杂散指标,并对跳频时间和相位噪声等指标进行简单预算,得到整个系统最大跳频时间小于1μs,相位噪声优于-106 d Bc/Hz/10 k Hz,杂散优于-60 d Bc。     

基于双环系统的细步进频率合成器

针对小数分频锁相的整数边带杂散问题提出了一种基于双环系统的细步进频率合成方法。根据变参考抑制小数分频整数边带杂散的工作原理,采用一级整数分频锁相环与一级小数分频锁相环级联的方法共同构成细步进频率合成系统,通过软件算法调整第一级锁相环的N分频值和M参数,最终实现全频段杂散指标最优。结果表明,根据该方法设计的宽带（带宽为4~8 GHz）、细步进（1 kHz）的频率合成器,其实测杂散优于75 dBc,相位噪声在1 kHz处优于-96 dBc/Hz,跳频时间小于47 μs     

一种雷达频率源的简易设计方法

针对传统多功能雷达频率源方案复杂、体积大、成本高的缺点,提出了一种雷达频率源的简易设计方法。该方法基于高频主振分频的频率合成方案,并通过信号频率的组合设计进一步简化了电路形式,成功实现了某型雷达所需的线性调频激励源、捷变频本振源、多普勒模拟源、采样时钟等多路信号的输出,X频段信号相位噪声达-106 dBc/Hz@1 kHz和-114 dBc/Hz@10 kHz,跳频时间小于2#s,性能指标与采用直接频率合成实现的雷达频率源相当。     

基于雷达信号模拟器的Ku波段宽带跳变源的设计

文章采用DDS驱动PLL的方式,实现了一种能完全覆盖Ku波段的宽带小步进低相位噪声低杂散频率合成器的设计,同时对DDS PLL频率合成器的输出特性进行了理论分析,并通过实验进行了验证.最终我们研制出了输出频率为12-18GHz的频综系统,步进为1MHz,相位噪声优于-90 dBc/Hz@10kHz,杂散优于-50dBc.     

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。     

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.     

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.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

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.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.