雷达频率合成器的快速捕获设计

现代雷达要求频率合成器的频率捷变时间很短,为达此目的,文章对间接式频率合成器的捷变频时间进行了分析,讨论了频率-数字变换辅助捕获法的设计过程及数学表达式,给出了设计流程图。     

磁控管的铁氧体电调捷变频技术研究

本文论述了磁控管铁氧体电调谐的原理,介绍了调谐输出耦合器的设计及铁氧体电调谐器的结构。最后给出了采用此种捷变频技术的实验研究结果。     

PIN管腔外电调频率捷变磁控管

引言随着捷变频技术的发展,对捷变频管频率捷变速度的要求越来越高。机械调谐速度慢,只能实现脉间变频,而电调管的调频速度可以大大提高,可实现脉内变频。本文介绍了在普通磁控管上附加一个PIN管调谐器来实现频率捷变的技术。在上灯及长风机器厂的协作下,制成了腔外PIN管电调频率捷变磁控管(401管),捷变带宽40～50兆赫、>10千瓦、跳频时间<30微秒,并进行了装机实验。测试结果表明,在捷变状态下工作稳定、频谱良好。这种管子与机调捷变频磁控管相比,没有     

捷变频中红外光参量振荡器实验研究

介绍一种快速调谐非共线光参量振荡器(OPO)。通过快速改变泵浦光与OPO中非线性光学晶体光轴的夹角,实现OPO的波长精确和快速调谐,光束入射时间、角度、速度和方向均由计算机控制,保证OPO的快速精确调谐。输出中红外激光波长3.1～4.2μm,最大输出能量9.8mJ。捷变频速率可达3.5×1012Hz/ms。     

L波段细步进捷变频频率综合器设计

介绍一种模块化的L波段细步进捷变频频率综合器,采用直接数字频率合成器实现细步进,采用上变频器＋倍频器来提高并扩展带宽。讨论其频率规划及功能模块划分,论述了关键指标设计、分析及实现,最后给出了测试结果。该方法可以在实现100Hz细步进的同时,杂散抑制大于65dBc,跳频时间小于1μs。     

S波段DDS频率源的研制

本文在简述直接数字频率合成（DDS）工作原理的基础上．介绍了一种基于DDS的全相参、捷变频、低相噪S波段雷达频率源的设计方法．并给出了测试结果。     

旋转调谐捷变频磁控管

我国近十年发展起来的旋转调谐捷变频磁控管,已成功地应用于海、陆、空多种捷变频雷达,通过多次试飞、试航、导弹打靶证明,这种新型磁控管的研制是成功的,器件工作稳定,性能良好。本文阐述了该管在研制中遇到的几个特殊技术问题。还简要叙述了旋转调谐捷变频磁控管的基本工作原理、真空驱动方法、谐振系统的计算方法、冷测、热测等。     

采用超导器件的数字直接合成器

对于像Link16多网络系统以及捷变频战术通信系统来说，快速频综转换器是非常关键的。传统的基于锁相环的频综器采用的是可调振荡器，例如一个锁向稳定频率时钟的压控振荡器（VCO），它的封锁时间和稳定时间就限制了频综器的转换速度。Hypres公司开发的直接数字合成器（DDS）采用了超导技术，克服了常温模拟频综器的转换速度限制。     

某机载抗振捷变频频综器设计

设计了1种用于某机载电子设备上的捷变频频率综合器。该合成器采用快捕、隔振技术以及数字锁相和谐波混频技术,在很小的体积内实现了合成器的低相噪、捷变频和抗振等性能指标。测试结果为:输出频率Ku波段,带宽480 MHz,跳频点数49点,相噪优于-96dBc/Hz/1kHz,杂波抑制优于-70 dBc,捷变频时间小于50μs。     

基于IP核的数字控制振荡器的设计

数字控制振荡器是数字变频与通讯系统的核心组成部分。本文研究了使用IP核设计数字控制振荡器的方法,对CORDIC波形生成算法行了分析,分析了波形信号中噪声产生的原因,通过添加相位加抖功能来实现降噪。为数字变频与通讯系统的设计提供了参考方法。     

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.     

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.     

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.     

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.     

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