一种计算波导耦合缝隙有源阻抗的方法

 针对耦合波导缝隙馈电时波导内电磁场复杂且不利于工程应用的问题,提出一种耦合波导缝隙有源阻抗计算方法.根据耦合波导端口处S矩阵与端口处输入阻抗矩阵的关系建立关于耦合波导缝隙有源阻抗方程,且采用牛顿法求解此非线性高阶分式方程,得到计及缝隙间互耦的耦合波导缝隙有源阻抗值.通过提取HFSS软件中耦合缝隙馈电的裂缝天线S矩阵进行仿真计算,结果表明该计算耦合缝隙有源阻抗的方法是有效的且适合大型裂缝天线耦合裂缝设计.     

复杂缝隙结构耦合特性数值仿真的等效方法

针对缝隙结构建模在计算精度与求解时间之间的矛盾,提出了一种基于转移阻抗的复杂缝隙等效建模方法,采用传输线矩阵法对大型方舱复杂缝隙结构的电磁耦合特性进行了仿真研究。仿真结果表明,该方法可大幅减少网格数量,有效缓解仿真精度和计算时间之间的矛盾。     

空间电磁辐射的缝隙仿真建模技术研究

缝隙是电子设备产生电磁场泄漏的主要途径,要正确预测电子设备的电磁兼容性能,就必须考虑缝隙引起的电磁场泄漏.因此,本文提出了一种空间电磁辐射的缝隙仿真建模技术,同时提出了等效缝隙模型中结构尺寸及材料属性的确定规则;最后通过仿真案例验证了该方法的准确性.     

缩短微机械圆盘谐振器缝隙的电极移动法

针对现有微机械(Micromechanical,也称MEMS)圆盘谐振器串联动态电阻过大的问题,该文提出了电极移动法,将其它MEMS器件的可调性能引入MEMS圆盘谐振器,在现有最窄缝隙工艺条件下实现了电极-圆盘缝隙的进一步缩减,降低了串联动态电阻。该文给出了悬置电极的设计方法,推导了电极移动后有效缝隙宽度的表达式,提出了可防电极接触短路的微小圆孔状凹陷设计,并给出了加入凹陷后的有效缝隙宽度表达式。通过ANSYS仿真结果可知,分别加载2.10 V和66.38 V偏置电压后,0.1 m和1 m电极-圆盘缝隙缩小为0.0016 m和0.01 m。对于0.1~1.1 m缝隙谐振器,串联动态电阻变为原来的10-8倍以下。     

波导缝隙阵天线的快速优化设计

本文利用Elliott设计方程考虑波导缝隙阵天线中单元间的耦合效应,提出"电流分布逼近"作为目标函数,利用遗传优化算法对谐振式波导缝隙阵天线进行方向图优化设计.本文设计了一个4元波导缝隙阵,证明了这种方法是有效的,并完成了一个8元缝隙阵的设计实例.数值结果表明,本文方法相比于传统"方向图逼近"优化方法更加快速有效,并且可以应用到大型的波导缝隙阵的设计之中.     

波导窄边缝隙阵天线的缝隙导纳的简易测量方法

正 (一)引言 串馈波导窄边缝隙阵天线是一种广泛应用的天线。波导缝隙电导与缝隙几何尺寸的关系是设计这种天线的基础,而缝隙导纳的频率特性则是分析天线频率特性所必不可少的依据。设计波导缝隙阵天线,虽有理论分析公式可以应用,但所得结果与实际情况还有出入;因此,设计之前,先测得波导缝隙的电导值。由于单个缝隙的电导值相当小,难以测准,加之缝隙之间又存在相互耦合,因此,人们都是测量多个(至少20个)缝隙的阵中的缝隙电导值。一般是采用测量S参量的方法,即测量波节点的移动,通过作图求得电导值。这种测量方法非常繁琐,而且精度也难保证。也有人采用行波功率法,但只能得到谐振频率上的电导值。至今尚未见到关于测量缝隙导纳的频率特性的简捷方     

新型Ku波段基片集成波导缝隙阵列天线设计

介绍了基片集成波导缝隙天线的相关理论,以及宽边基片集成波导缝隙驻波阵的设计方法。首先,根据指标要求,利用HFSS电磁仿真软件来获取缝隙初始导纳参数;然后,使用Matlab软件进行数据拟合;最终,得到缝隙电导与缝隙偏置的数学函数。采用该方法设计了中心频率为15. 9 GHz 的4 元等幅同相的驻波直线阵,仿真得到在15. 8 GHz ~16 GHz 频段内驻波比小于1. 88。     

任意镜像阻抗平行耦合线滤波器的设计

任意镜像阻抗平行耦合线滤波器与传统的平行耦合线滤波器相比,通过选择合理的镜像阻抗,可以得到合适的耦合线的宽度与缝隙,因而使滤波器更容易加工。首先从理论上推导了任意镜像阻抗平行耦合线滤波器的设计公式。根据此理论,设计了80Ω的任意镜像阻抗平行耦合线滤波器。通过EM仿真验证了设计公式的正确性与准确性。     

频扫单脉冲天线技术研究

为了提高采用频扫天线的雷达系统在频扫维的测角能力,本文重点讨论了频扫单脉冲天线的实现技术,分析了三种不同实现方法,并以带状线形式、脊波导宽边缝隙形式和窄边波导缝隙形式为具体实现形式,设计了三种基于不同实现原理的频扫单脉冲天线实例,仿真及实测结果表明,三种实现方法都的有效性和正确性,可以应用于实际工程中.     

大型波导纵缝阵列天线的分析与设计

本文利用矩量法和等效网络法对矩形波导宽边纵缝阵列进行了精确的理论分析，严格计算阵中缝隙的内部和外部互耦，并利用等效网络法提取阵中缝隙的等效导纳特性。在此基础上，提出模型阵列和模型缝隙的大型波导缝隙阵的设计方法．理论结果与实验比较吻合。     

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.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

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.