基于NUFFT方法的二维非周期阵列天线方向图计算

相控阵天线应用在有限电扫描角度时,采用大间距体制以减少有源通道数量,降低天线成本。由于单元间距大于波长,在可视空域内会出现栅瓣,常采用非周期排列方法分散栅瓣能量降低栅瓣电平。文中提出了一种变距平移错位抑制大间距阵列栅瓣的方法,并介绍了基于二维NUFFT计算该非周期排列阵列天线方向图的方法。分析了影响该算法精度的因素,并通过在拟合虚拟阵列幅相值时通过采用局部坐标系有效减小计算量。通过一个由300个单元组成的非周期阵列方向图计算,对二维NUFFT方法以及累加法进行对比。前者的计算时间仅为后者的0. 9% ,验证了算法的高效性。计算结果显示全空域方向图吻合度高,方向性系数误差仅0. 05 dB,最高副瓣误差仅0. 12 dB,验证了算法的准确性。     

采用FFT-PSO策略的多约束稀疏阵天线方向图综合

采用稀疏布阵的相控阵测控天线,阵元等幅激励时的阵列峰值副瓣电平无法满足指标要求.在考虑天线增益、半功率波束宽度等指标约束时设计了合适的适应度函数,并基于粒子群算法(PSO)对阵元激励幅度进行优化以降低天线副瓣电平.同时,分析了等间距栅格平面阵列天线方向图与离散傅里叶变换的关系,采用快速傅里叶变换(FFT)降低了阵列方向图计算复杂度.仿真结果表明,该方法可有效降低峰值副瓣电平和计算复杂度.     

混合算法在稀布阵设计中的应用

提出把混合优化算法IGA-EDSPSO(Improved Genetic Algorithm-Extremum Disturbed Simple Particle Swarm Optimization)和基于RWG基函数的MoM-PO混合算法用于最小阵元间距约束的稀布阵列设计中.通过调整阵元间距来优化辐射阵因子,改善了阵列天线的辐射性能.与以前的方法相比,该方法在处理大型阵列时,降低了对计算机资源的需求,有效地实现了考虑互耦情况下副瓣电平的抑制,真实地考虑了天线的整个结构对于方向图的影响,对低副瓣电平阵列天线的设计有一定的指导意义和参考价值.     

大摆角摆臂式干涉仪非线性干涉信号光谱反演

为快速实现大摆角摆臂式干涉仪非线性干涉信号的光谱反演,通过分析大摆角摆臂式干涉仪的工作过程和干涉信号的非线性对光谱反演的影响,提出了基于非均匀快速傅里叶变换(NUFFT)的光谱反演方法。该方法先利用核函数和卷积算法让非线性干涉信号线性化,然后对线性化的干涉信号进行快速傅立叶变换实现光谱反演。实验将光程差替换法和NUFFT算法分别应用于非线性干涉信号的光谱反演。结果表明:两者光谱反演精度相近,但NUFFT算法速度更高。     

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。     

一种唯相位加权降低天线副瓣技术研究

通过分析几种优化阵列副瓣算法的特点,提出将差分进化算法与模拟退火方法相结合的方法,实现了唯相位加权降低阵列天线副瓣。采用快速傅里叶变换法提高计算阵列天线方向图的效率。为了证明该方法的有效性,给出了40×40均匀阵列的唯相位加权低副瓣优化结果,阵列天线副瓣唯相位加权优化后达到了-22.13 d B。     

77 GHz汽车角雷达宽波束平坦增益阵列天线设计

设计了一款基于波束赋形技术的宽波束、平坦增益平面阵列天线,用于汽车角雷达系统.该阵列天线由三个1×10串馈线阵组成,串馈线阵采用单元不等间距分布的Dolph-Chebyshev天线综合法进行设计以降低副瓣.为了满足汽车角雷达宽视场角(field of view,FOV)的需求,对平面阵列天线采用波束赋形技术以展宽方位面...     

迭代傅里叶算法用于六边形稀疏阵列天线

针对迭代傅里叶技术在优化稀疏阵列天线时对阵元激励大规模截断带来的不利影响,提出了一种逐步截断的迭代傅里叶算法.该算法从满阵依次减少数个阵元,从而避免阵列大规模截断陷入局部最优解.将其应用到六边形平面天线阵列的稀疏布阵优化中,以改善最大副瓣电平为目的.为了计算六边形天线阵的方向图,通过在口径中添加虚拟阵元转化为可以实现二维傅里叶变换的矩形阵列.仿真结果表明,改进的迭代傅里叶算法对稀疏天线阵最大旁瓣电平的优化比采用遗传算法的结果更理想,且具有计算量小和速度快等优点.     

非周期阵列天线辐射性能的研究

针对非周期大间距矩形阵列,运用遗传算法对其进行优化布阵和幅度加权,得到各阵元最佳的位置和幅度分布,使得阵列扫描范围内的副瓣电平最低。研究了阵元间距、阵列扫描范围、单元天线波束宽度等3种因素对阵列副瓣电平和增益的影响,得到了各因素对阵列辐射性能影响的规律。通过遗传算法优化得到了扫描范围内副瓣电平最低时的阵元间距,可用于指导工程设计。     

基于遗传算法和模拟退火的不等间距稀布阵的设计

副瓣电平在天线阵列的设计中是很重要的指标,已经有很多方法进行这方面的改进。该文在稀布阵概念的基础上,引入了距离微扰,提出不等间距稀布阵的模型,来进一步改善天线阵的副瓣电平,并且利用遗传算法和模拟退火对这种不等间距稀布阵进行了综合设计。给出了200元线阵和4020面阵的优化结果,从仿真结果可以看到天线副瓣电平得到了改善。     

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.     

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     

JOURNAL OF ELECTRONICS(CHINA)

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NOTICE OF CHANGING JOURNAL OF ELECTRONICS （CHINA） TO MICROSYSTEMS ＆ NANOENGINEERING

正Journal of Electronics(China)(JE)was founded in 1984,sponsored by the Institute of Electronics,Chinese Academy of Sciences.JE is one of the first English academic journals in China in the field of Electronics and Information technology.The journal was published quarterly since it was launched in 1984 to 2003,then it is published bimonthly till now.During