针对双基地雷达的分布式干扰研究

接收站位置未知使得传统的干扰手段很难对双基地雷达形成理想的干扰效果.针对这种情况,文中从战术角度出发,对双基地雷达的分布式干扰问题进行研究.以发射站、接收站联合发现概率为效能指标,对不同布站方式下的双基地雷达分布式干扰效能进行评估.计算机仿真试验表明,空域分布特性是分布式干扰对抗双基地雷达的优势;通过战术设计,提高分布式干扰机的作战效能,可以在一定程度上削弱接收站未知带来的不利影响.     

双基地高频地波雷达系统布站研究

由发射机(T)和接收机(Rm)共站的单基地高频地波雷达增设分置的接收系统(Rb)构成的T/Rm-Rb双基地高频地波雷达系统用于海洋环境监测时,既可测得矢量流速度,又可消除风向模糊性,是目前高频地波雷达的发展趋势之一。该文首次从T/Rm-Rb系统的探测能力与海流测量误差两方面分析最佳基线长度和最佳双基地角范围,从而确定其布站原则,即:在确定T/Rm单基地雷达的位置后,先根据T-Rb双基地雷达设计指标中的最大探测距离和确定基线长度,然后根据T/Rm-Rb系统海流测量误差最小的原则确定最佳双基地角范围,从而确定T-Rb双基地雷达接收站Rb的位置。该布站原则可为双(多)基地高频地波雷达的海洋环境监测应用提供参考和依据。     

GPS在运动平台上双/多基地雷达中的应用

利用全球定位系统(GPS)对运动平台上双/多基地雷达的接收站进行定位,根据GPS提供的接收站经纬度信息,推导了接收站相对于发射站的距离和方位角的计算公式。再根据对目标的测量结果,通过坐标变换得到目标的位置信息。定量分析了GPS定位误差对接收站定位和目标定位精度的影响,结果表明GPS可以满足该雷达系统的要求。     

T/R-R双基地雷达进动目标参数估计与ISAR成像

以锥体目标为研究对象,建立了双基地雷达进动目标宽带回波模型,提出了基于两个接收站观测的1维距离像序列和扩展Hough变换的进动参数联合估计方法;建立了进动目标双基地ISAR成像模型,推导了双基地IS-AR成像最佳时间,并通过前述参数估计结果选择对应的1维距离像,采用FFT实现横向压缩获得了进动目标双基地ISAR像;采用FEKO软件计算了一个锥体模型的单/双基地散射系数并进行动态仿真,仿真结果验证了本文方法的有效性.     

分布式压制性干扰下的双基地雷达探测能力研究

双基地雷达由于其收、发站分置具有较好的抗干扰性能。从双基地雷达方程和压制性干扰带来的热噪声的变化出发,推导出了对双基地雷达进行分布式压制性干扰的数学模型。分析了分布式干扰下各种干扰情况对双基地雷达探测能力的影响,并与自卫式干扰和远距离支援式干扰进行了比较。仿真结果表明,对双基地雷达实施分布式压制性干扰可以达到较好效果。     

数字化频率分集的脉冲雷达补盲方法研究与实现

针对某型脉冲雷达对最小探测距离的要求，本文介绍了一种利用双频双脉冲形式进行近区补盲的方法，并且针对该方法设计了在接收机的单通道内实现数字化频率分集的工作方式。 首先，为解决脉冲雷达探测距离存在近区盲区的问题，给出了宽、窄相结合的双频双脉冲的补盲方法，以达到雷达最小探测距离的要求。然后，利用数字化频率分集的思想在接收机单通道内完成双频双脉冲的频率分离，既实现了补盲效果，也突破了传统补盲方法下接收机通道必须完全或部分复制的固有方式，减小了接收系统的体积和复杂度，从而促进脉冲雷达系统实现小型化、轻量化。最后，在某型雷达接收系统中进行了性能测试，验证了本文方法的有效性和实用性。并且该型雷达已经完成了外场试验，最小探测距离符合要求，表明利用数字化频率分集的方式实现脉冲雷达接收机单通道的双频双脉冲补盲方法应用可行。     

T-R型双基地跟踪雷达有关问题及仿真分析

雷达在电子对抗中起着极其重要的作用。本文针对T-R型双基地跟踪雷达,分析了系统的特殊性及要解决的关键技术问题,介绍了发射站和接收站之间的时间同步、频率同步和空间同步技术,分析了传统的单基距解算方法的不足,讨论了基于调整发射站触发脉冲和接收站测距同步脉冲两种距离解算方法,对双基地雷达测量值的校准方法进行了描述,最后对双基地雷达的定位准确度及采用联网多基地雷达系统提高距离的定位准确度进行了研究。仿真结果表明,联网双（多）基地雷达的数据融合,可明显改善基线附近的单基距准确度。     

双基地雷达试验系统

双/多基地雷达是对抗隐身、低空突防、反辐射导弹和综合性电子干扰等雷达四大威胁的一种有效体制。 该系统是以JY-9和××4雷达为主站的混合式脉冲追赶式双基地雷达。接收站综合运用了微带阵列天线、MMIC接收机、中频采样     

靶场测量中双基地雷达目标角度定位与定位精度分析

通过为靶场测量中的远程预警相控阵雷达配备接收站,组成合作式T/R-R双基地雷达系统,可提高其测量精度。本文通过靶场T/R-R双基地雷达几何关系分布,对观测目标建立三种角度定位及定位精度模型,并进行仿真分析,仿真结果表明该T/R-R双基地模型可大大提高角度定位精度,为靶场远程预警相控阵雷达增加接收机是有意义的。     

不同干扰决策准则下的双基地雷达探测能力研究

针对双基地雷达具有的四抗优势,本文基于决策准则研究了不同干扰方式下双基地雷达的探测能力.从能量角度出发推导了双基地雷达方程和干扰方程,建立了双基地雷达探测区的计算模型,探论了悲观准则和乐观准则下双基地雷达探测能力的变化规律,研究了自卫干扰和远距离支援干扰对双基地雷达干扰暴露区的影响,给出了几种典型情况下的计算机仿真结果,并通过分析得出了一些有益的结论,为双基地雷达的布站和抗干扰能力分析提供了重要的理论价值,也验证了双基地雷达比单基地雷达具有更强的抗干扰能力.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

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.