基于时域弹跳射线法的海面复合目标近场回波仿真

雷达回波信号的获取对研究动态目标识别和雷达成像具有十分重要的意义。提出了一种基于时域弹跳射线法(Time Domain Shooting and Bouncing Ray, TDSBR)的动态目标回波仿真模型,用于模拟海上电大目标的近场雷达回波。该模型采用TDSBR方法直接在时域计算弹载雷达照射下的目标与海面近场复合散射特性,并结合“stop-go”方法模拟雷达与目标之间的相对运动,实现了弹载雷达照射下海上运动舰船目标的回波信号仿真。仿真结果表明,该模型可以有效呈现海面与海上目标的耦合效应,实现对目标速度和距离的预测,具有良好的精度和较高的效率,在海洋环境中弹载雷达的回波预测和目标检测中具有广阔的应用前景。     

空间进动目标的宽带雷达特征信号研究

 本文将空间目标进动模型、宽带电磁散射计算模型以及线性调频(LFM)雷达回波信号模型相结合,提出了一种空间进动目标宽带雷达特征信号预测与高逼真度仿真的方法.利用进动目标的微波暗室测量数据,从雷达散射截面(RCS)和高分辨一维距离像时间序列两方面对模型的逼真度进行了验证,并在此基础上仿真了空间目标的动态宽带LFM雷达回波,分析了理想点散射体仿真进动目标特征信号的局限性和成对回波对雷达成像的影响.     

基于GRECO的复杂目标ISAR图像仿真

提出一种与图形电磁计算方法相结合的1SAR图像实时仿真方法.利用图形电磁计算(GRECO)方法得到运动目标的电磁散射数据,通过发射线性调频信号得到运动目标的雷达回波,并对仿真回波进行ISAR成像处理.与传统采用点目标仿真不同,该文是对实际三维目标直接仿真成像,更加接近实际,更加适合应用与成像效果分析、算法改进和抗干扰方面的研究.对于目标表面散射场的分析,是基于高频预估理论:采用物理光学(PO)法与物理绕射理论(PTD)来进行计算.从对复杂目标的仿真结果来看,该方法是准确有效且具有实时性的.     

基于实采数据的雷达目标回波模拟

对雷达操作人员的培训必须基于接近真实的模拟训练环境才能达到较好的训练效果。通过真实采集的雷达回波信号来模拟产生目标回波,利用目标数据库的生成,目标在不同统计模型下信号强度的计算,得到了一种逼真的雷达目标回波信号。模拟仿真试验验证了实际回波效果,结果表明该方法生成的回波能构建真实的模拟训练环境,使受训人员得到身临其境的模拟效果。     

高速运动目标宽带雷达回波频域模拟及分析

该文提出了一种高速运动目标宽带雷达回波频域模拟方法。根据雷达波与运动目标相互作用的物理过程建立了运动目标宽带雷达回波的频谱模型,提出了一种雷达回波的频域建模流程,分析了目标径向距离和径向速度对LFM 信号匹配滤波结果的影响,推导了高分辨率距离像(HRRP)平移和扩展的定量结论。仿真结果验证了该方法的正确性和有效性。      

基于MIMO噪声雷达的高速运动目标检测

针对传统体制雷达对高速运动目标不能进行长时间有效相参积累检测问题,该文提出了一种基于MIMO噪声雷达的高速运动目标检测方法。该方法利用MIMO噪声雷达在短时间内输出的多路回波数据进行相参并行处理来取代回波数据的长时间相参积累检测,以避免距离走动,径向速度变化以及反射截面积(RCS)快起伏等非平稳因素对目标检测的影响,有效实现了多个高速运动目标的无模糊检测。仿真结果验证了MIMO噪声雷达在高速运动目标检测方面的优越性。     

动态雷达目标仿真中目标姿态角的计算

为了对动态雷达目标建立合适的数学模型,逼真地复现目标的运动特性和回波特性,从而实现动目标仿真,提出了利用野外真实试验中实际测得的目标RCS数据建立动目标仿真模型,实现动态雷达目标仿真的一种新方法.文章首先探讨了采用该方法对动态雷达目标RCS仿真的具体步骤,然后对实现仿真的一项关键技术--运动目标姿态角的求解进行了公式推导,并列举了应用实例,为进行良好的动态雷达目标仿真提出了一个新思路.要实现仿真还需要做许多工作,如对动态目标RCS起伏规律进行分析,计算统计参数,应用常见RCS起伏模型对目标动态RCS统计分布进行拟合等.     

基于场景定义的弹道目标雷达回波仿真方法

回波仿真是开展系统论证和算法研究的基础。传统的弹道目标雷达回波仿真研究侧重对弹道目标和干扰信号各自特性的建模,缺乏系统级联合仿真途径。文中介绍了一种基于场景定义的弹道目标动态雷达回波仿真方法。该方法基于统一的人工场景定义平台,结合弹道轨道运动模型、摆动模型和电磁干扰模型,模拟产生高逼真度的摆动弹道目标雷达回波。该方法还可灵活接入暗室或靶场实测的目标雷达散射截面数据和干扰样本数据,为复杂电磁环境下的导弹目标探测和识别算法研究提供数据支撑。     

基于一维距离像的抗干扰方法研究

雷达探测领域,各种虚假目标的主动干扰对单体雷达目标探测带来了极大挑战。为了提高单体雷达的抗干扰性能,文中基于宽带雷达目标回波数据,计算了多角度一维距离像,并作为标签训练数据,引进成熟的卷积神经映射网络,通过大量虚假目标与真实目标回波的训练调参,成功构建雷达目标识别网络,可以从雷达接收机大量各类型中频回波数据中提取真实雷达目标。文中的雷达特征数据是通过CST软件进行三维目标建模仿真计算得到的,为了提高网络识别的鲁棒性,在仿真雷达目标回波样本的基础上增加了微小的扰动,雷达目标提取网络可以依据训练数据的增大而使得雷达目标探测更加准确。     

一种用于雷达资源管理的目标雷达截面积预测算法

在管理与优化雷达有限资源的应用中,目标的雷达截面积的起伏会对资源分配后的效果产生巨大的影响。针对该问题,该文提出一种对目标的雷达截面积进行预测的方法。该方法首先对回波进行处理以获取目标雷达截面积的测量值,进而通过概率密度转移的方法对目标在下一个时刻的雷达截面积进行预测。通过对来自3种飞机的雷达实测数据的计算,验证了该预测方法能够得到较为准确的预测值。最后,建立功率分配的优化方程,并通过仿真验证了对雷达截面积准确的预测能够提高功率分配后的测量精度。     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

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