一种实用的相控阵近场诊断新方法

提出了一种相控阵天线近场诊断的新方法.传统的方法要诊断出相控阵天线单元的激励,必须已知阵列单元的方向图和探头的方向图.文中基于相控阵天线的激励、单元方向图、探头方向图和近场测量数据之间的关系,得到了相控阵天线的激励和近场测量数据之间的耦合方程.利用多项式插值,在不必已知单元方向图和探头方向图的情况下,求解出相控阵天线的单元激励.     

基于粒子群算法的天线阵方向图优化

雷达阵列天线常涉及方向图综合,而天线阵综合常常是利用优化算法优化单元幅相及间距等参数的过程。粒子群算法具有理论简单、参数少和易于实现等特点,文中基于这一简单易行的优化算法,给出一种阵列天线赋形波束综合方法。通过优化阵列天线中各单元的馈电幅度和相位同时实现主瓣的赋形和副瓣电平的抑制,或通过仅相位加权实现主瓣波束赋形,得到优良的余割平方赋形。通过实例设计验证了粒子群算法优化天线阵方向图的有效性。     

基于自适应遗传算法的星载SAR天线方向图与模糊综合

该文针对改善星载合成孔径雷达(SAR)的模糊特性,提出了一种自适应遗传算法。该算法同时对模糊和方向图进行优化。首先确定模糊区域,然后以天线方向图的主瓣宽度和副瓣电平(包括星载SAR模糊区域的副瓣电平)为目标函数,应用自适应遗传算法对天线方向图进行综合。为了避免早熟的现象,在该算法中,交叉概率、变异概率和变异范围同时进行了自适应的变化。和非自适应遗传算法相比较,该算法迭代步骤少,收敛速度快。仿真结果表明,模糊度得到了很好的抑制,对星载SAR系统设计具有实际意义。     

考虑互耦影响的阵列综合

阵列天线综合一般是基于理想的单元天线方向图，而不考虑阵元间的互耦。本文提出了一种考虑互耦的基于遗传算法的阵列天线综合方法。该方法首先利用商用仿真软件分别计算阵列中各个阵元在阵列中的方向图，再通过遗传算法优化出目标方向图。通过实例比较可以看出，这种方法能够比较精确的仿真计算阵列的方向图，易于在工程上实现高性能的天线阵列系统。     

二维阵列天线方向图综合算法研究

在阵列天线的应用中,需要控制阵列天线的方向图达到合适的副瓣电平要求。本文在对已有的一维阵列方向图综合算法进行研究的基础上,给出了一种基于自适应阵列信号处理理论的二维阵列天线方向图的综合算法,将待综合阵列假想为自适应阵列,通过不断调节对阵列施加的干扰,再由自适应算法调节阵列权值,最终得到合适的方向图。     

低副瓣任意波束直接合成算法研究

在传统阵列天线波束赋形设计中，通过对阵元天线辐射方向图进行幅度相位加权，获得阵列合成方向图.通常阵元激励幅度相位权值的获取，取决于优化算法对目标方向图和阵列合成方向图的对比，通过对阵元激励幅度相位进行大量随机选参后，获得优化结果.由于算法通常是基于相关的阵元方向图，且算法中缺乏副瓣抑制机制，使得方向图合成效率不高且副瓣效果通常不理想.该文设计了一种任意波束直接合成算法.该方法首先在阵元方向图的基础上获得一组互相独立的高增益窄波束（自由基波束），然后基于此波束进行方向图的直接合成，使波束赋形问题统一到基于自由基波束权值运算的范畴内，对波束赋形问题进行了统一，避免了未知参量的随机优选过程，极大提升了阵列天线波束赋形设计的效率.同时在自由基设计的过程中结合了副瓣抑制机制，且这种副瓣抑制机制与波束赋形过程互相独立，使合成波束的副瓣天然地具备了低副瓣的特征.     

无线电设备、电信设备

TN802 2007011063粒子群优化算法用于阵列天线方向图综合设计/焦永昌,杨科,陈胜兵,张福顺(西安电子科技大学天线与微波技术国家重点实验室)//电波科学学报.―2006,21(1).―16～20,25.粒子群优化算法是基于一群粒子的智能运动而产生的一类随机进化算法,其优点是算法非常利于理解和应用。该文介绍了粒子群算法的原理和流程,研究了如何将该方法运用于天线阵的方向图综合上,给出了PSO算法在综合阵列方向图的应用实例,表明粒子群算法在天线阵列综合中具有广泛的应用前景。图6表3参13     

一种基于遗传算法的阵列天线方向图综合

基于排序的实数码遗传算法实现对阵列天线方向图综合,并对遗传参数作了一些改进.该算法使得搜索效率有很大的提高,有效避免了早期收敛.通过计算机仿真实验,该算法成功地实现了阵列天线的方向图综合.通过对阵列天线的阵元电流幅值进行优化,同样可以达到传统方法所能实现的效果.良好的仿真结果体现了遗传算法在阵列天线方向图综合中的优越性能.     

一种基于双正交模的新型天线阵方向图综合方法

本文提出一种新型综合阵列天线方向图的模式方法。该方法基于双正交模式理论,考虑了阵元之间的耦合作用的影响,可以对任意形状的阵列天线进行方向图综合。利用双正交模式综合方法可以快速有效地获得每个阵元的特定激励,以期阵列天线的方向图满足特定的需求。模式组之间的双正交特性保证了该方法所得天线阵列方向图与期望方向图之间良好的一致性。通过对所需电场的加权,可以将整个球面上的二维曲面积分运算转化为一维线积分运算,使得方向图综合过程的计算量大为减少。若干阵列天线方向图综合实例验证了该方法的正确性和有效性。     

数字波束方向图综合技术

数字波束形成技术充分利用了阵列天线所检测到的空间信息,可以获得超分辨率和低副瓣的性能、实现波束扫描和波束赋形等。提出一种基于线性约束最小方差波束形成算法的方向图综合算法,算法通过迭代运算,能够获得需要的方向图形状。算法仿真以降低由24个天线单元组成的均匀圆阵的方向图副瓣为例,通过3次迭代运算,将副瓣电平降至-40dB左右,满足了工程需要,说明算法是有效、可行的。     

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.     

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.     

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.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first