直角坐标下正弦分布面电流元近场分析

本文从并矢格林函数的场方程出发,研究直角坐标下长方形电流元的场分布,分别给出考虑线电荷影响及不考虑线电荷影响两种情况下用指数积分表示的严格近场表达式,指出该表达式同时适用于求解面元表面近场。     

正弦电流单极子近场公式的一点注解

正弦电流单极子两端存在端电荷,电荷密度存在奇异点。论文针对Riemann积分意义下,无法对电荷密度分布函数积分获得正确的标势函数的问题,通过引入电荷分布函数,将Riemann积分改写为Stieltjes积分,在Lebegue-Stieltjes积分意义下,重新推导出相应的标量势和矢量势函数,并得到考虑端电荷影响时,正弦电流单极子近场的正确表达式,该计算式在忽略端电荷场影响下与已有结果相同。     

时域物理光学后向散射近场线积分表达式

提出了一种计算偶极子源照射时理想导体平板后向散射近场的时域物理光学（Time-Domain Physical-Optics,TDPO）线积分表达式.利用并矢分析中的面梯度定理和面散度定理,将TDPO面积分表达式化为线积分表达式.该表达式消除了积分中的奇异性,适用于偶极子天线处在任意位置处的情形.计算了导体平板和复杂目标的瞬态后向散射场,与其他方法结果吻合良好.数值结果表明,该方法在保证计算精度的前提下,可以大大提高计算效率.     

电流元近场照射下球体目标散射的解析解

得到了目标坐标系中电流元辐射近场的表达式,验证了该函数的正确性。在目标坐标系中将电流元的辐射近场、散射场等用球矢量波函数展开,利用球矢量波函数的正交性得到了展开系数并给出了其数值结果及物理分析。在天线近场照射下,得到了目标散射场的解析解,对所得结果进行了数值仿真,利用矩量法验证了结果的正确性。结果表明,天线近场照射目标时,目标上的电磁波为TE波和纵波,纵波是目标散射的主要因素,测量角θ对散射的影响较大。该方法可用于其他天线如相控阵天线等照射下目标散射以及目标电磁相互作用等领域的研究。     

考虑空间电荷场的Orotron的大信号理论研究

本文讨论了Orotron的大讯号计算中空间电荷的影响。首先推导出直角坐标系统中,当一个边界为无限大时的空间电荷场的近似表达式,然后利用这一空间电荷场模型,计算了Orotron的自洽的大信号相互作用,讨论了空间电荷参量对器件性能的影响。     

非对称电偶极在地层中的热效应解析解

用近似法分析了有耗媒质中非对称电偶极的激励场,得到一个场和焦耳热的简单的解析表达式。与传统的对称型半波振子公式相比较,其下端导体的电流分布表达式相同,当下端导体为四分之一波长时激励近场表达式相近。结合典型储油层给出一些计算结果,对电磁波采油技术有参考价值。     

单场限环结构击穿电压的表面电荷效应分析

本文利用计及表面电荷的柱面结电场分布表达式，并根据场限环优化条件，首次建立了单场限环表面电荷效应优化模型，得到了考虑表面电荷效应后，优化单场限环结构击穿电压以及优化环间距的归一化计算公式．分析了表面电荷密度对场限环结构耐压和优化环间距的影响，计算结果与文献中的数值模拟结果相符合，推得的公式可应用于场限环结构的实际设计     

表面电荷效应对场限环优化设计的影响

本文利用计及表面电荷的柱面结电场分布表达式，并根据场限环优化条件，首次建立了单场限环表面电荷效应优化模型，得到了考虑表面电荷效应后，优化单场限环洁构击穿电压以及优化环间距的归一化计算公式。分析了表面电荷密度对场限环结构耐压和优化环间距的影响，计算结果与文献中的数值模拟结果相符合，推得的公式可应用于场限环结构的实际设计。     

不同初始分布向列相液晶电容特性的相场法研究

液晶盒内的液晶分子在不同的外加电场作用下重新排布,其极化指向发生改变,从而影响液晶盒整体的电学特性。本文考虑液晶材料的挠曲电效应,分析液晶盒的整体自由能表达式,包含弹性形变自由能密度、介电自由能密度和挠曲电自由能密度。基于液晶弹性理论和相场方法,构建描述液晶核指向矢分布及演化的相场方程,并运用离散方法推导出液晶盒约化电容的表达式。讨论边界强锚定的混合液晶盒(HAN)和平行液晶盒(PAN)表面电荷密度对液晶核指向矢偏转角的影响。进一步分析了挠曲电系数、表面电荷密度以及液晶盒厚度对两种不同初始指向分布液晶盒电容性能的影响。数值分析结果表明,表面电荷密度越大、挠曲电系数越小,液晶核指向矢偏角越大。在混合液晶盒中,约化电容随着表面电荷或液晶厚度的增加而增加,最终趋于饱和;而在平行液晶盒中,当表面电荷密度或液晶盒厚度达到某个临界值时,液晶核的指向矢才发生改变,液晶的约化电容才有明显的变化。随着表面电荷密度增加,液晶核指向矢发生偏转的临界厚度减小。     

基于图形电磁学的近场角闪烁预估方法研究

角闪烁的研究大多基于远场条件的假设,但是近场条件下,角闪烁对雷达的跟踪误差产生更大影响,近场角闪烁的研究更加具有学术和实际工程应用意义。该文推导了近场条件下角闪烁线偏差的解析计算方法,并将图形电磁学(GRECO)应用到近场角闪烁的预估中,使其具有实时性强、电大目标计算的能力且不需要散射中心的提取过程。雷达波束不完全覆盖目标的情况被首次考虑,使得全程估计目标的雷达跟踪误差成为可能。通过不同模型的仿真计算结果与理论计算结果比较,验证了计算方法的正确性。     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

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.     

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.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.