低功耗跨导-电容滤波器及其调谐电路的设计

设计了一种以Nauta跨导为单元结构的5阶切比雪夫跨导-电容带通滤波器及其调谐电路.该电路应用于低中频结构的北斗卫星导航接收机射频前端.滤波器的中心频率为4.092MHz,带宽设计为±2.046 MHz.该滤波器采用锁相环结构的片上自动频率调谐电路,用TSMC0.13 μm RF CMOS工艺实现,芯片面积仅为0.24 mm2,可以在低电压下工作,电路总功耗仅为1.68 mW.     

GNSS多频通用射频模块设计与实现

多个全球导航卫星系统（GNSS）已经投入使用,卫星导航接收机的研发呈现出多频多模融合的特点。多系统多频点的设计对射频前端的设计提出了挑战。为了能让射频模块可以利用软件控制且满足多系统多频点的系统需求,采用AD8347与SI4133设计出灵活设置频点的多频通用射频前端模块。根据SI4133的要求设计外部电感,完成通用射频模块的设计。多频通用模块通过与接收机基带处理平台的搭配,实现多系统多频点的卫星信号处理;通过合理设置中频滤波器参数与本振频率,L1,B1这两个相近的频点可以实现同时变频处理。经过验证,该多频通用射频模块可满足GPS L1、北斗B1/B3、GLONASS L1单点定位的需求,并可应用于RTK接收机中实现厘米级的定位。     

一种北斗接收机基带处理设计方案

基带信号处理部分是北斗接收机重要的组成部分,主要是对射频通道输出的中频模拟信号数字采样后,实现数字正交下变频、捕获、跟踪,最终完成导航观测量的输出。文章采用基于分段匹配滤波+FFT频率估计的捕获方式;采用非相干锁定环实现码的跟踪,采用相干跟踪环+非相干跟踪环结合的方式实现载波跟踪环路;为北斗接收机基带信号处理提供了一种设计方案。     

基于GP2010的移动GPS射频前端设计

对GPS射频前端进行了研究与设计,实现了GPS信号射频到数字中频的转化过程。应用GP2010芯片设计出了符合要求的GPS射频前端,包括前端滤波器、低噪声放大器,以及中频滤波器。介绍测试系统的搭建,对实际制作的电路板进行调试,并得出测试结果,为后期基于FPGA实现GPS基带数字信号处理提供GPS数字中频信号,为自主设计GPS接收机奠定了基础。     

一款低噪声卫星导航接收机射频前端的设计

基于0.18tm RF CMOS工艺,采用低中频系统结构,设计了一款可应用于全球定位导航系统(GPS) L1频段和北斗二代(BD2) B1频段的低噪声卫星导航接收机的射频模拟前端芯片.该前端包括低噪声放大器、无源混频器、中频放大器、复数带通滤波器和数控可变增益放大器.其中低噪声放大器采用电流舵技术,与无源混频器一起,提高了射频前端的1 dB压缩点输入功率(Pi(1dB)),有效地改善了系统的线性度.测试结果显示,在GPS L1频点,系统的最大增益107.2 dB,噪声系数达到1.8 dB,动态增益66 dB,镜像抑制比约为39.54 dB,Pi(1dB)为-41 dBm,电源为1.8V时,消耗电流16 mA,芯片面积1.7 mm×0.8 mm.     

GPS软件接收机基带信号处理研究

GPS软件接收机相对传统硬件接收机,设计灵活,能够迅速分析、仿真、实现各类算法.本文主要针对GPS L1频率的C/A码信号,设计并实现了GPS软件接收机的基带处理部分,阐述了射频前端原理、并行码相位搜索捕获策略以及鉴频辅助跟踪环路,并推导了适应动态环境的三阶数字环路滤波器.仿真数据和实际中频数据测试表明:算法性能优越,能迅速捕获并锁定信号,获取导航数据.     

模拟中频滤波幅相特性对微波着陆相位信号解算的影响分析

在微波着陆机载接收机中,射频通道将 C 波段信号变换为中频信号,中频信号通过模拟中频滤波器送入到后级处理,模拟中频滤波器的幅相特性特别是相位特性的好坏对后级解算相位信息影响较大,合理的认识评价模拟中频滤波器特性对整机相位信号的影响,是设计与考核模拟中频滤波器的基础。本文介绍了微波着陆机载设备相位信号解算处理通路及原理,并从系统角度给出了模拟中频滤波器特性对与系统相位信号解算的影响,为模拟中频滤波器的设计及系统评价模拟滤波器的性能做出参考。     

价格便宜的家用卫星电视接收机

日本有几家公司研制出了可供家庭使用的卫星电视接收机,这种接收机使得象直播卫星那样的服务更接近现实。东芝公司声称,这种接收机用的波导、射频和中频放大器以及带通滤波器取得了成本和性能两项突破。     

一种抑制数字接收机镜像干扰的方法

现代脉冲多普勒体制雷达常规数字中频接收机大多采用带通采样方式。由于雷达信号一般采用脉冲波形,数字接收机在对射频回波下变频数字化后,对A/D数据进行时频谱分析时往往在脉冲边沿处会产生较大的镜像干扰。本文分析了脉冲多普勒雷达常规数字中频接收机在处理脉冲信号时脉冲边沿镜像干扰产生的机理,指出了中频带通滤波器在数字中频接收机链路中的主要作用,着重对中频带通滤波器的指标体系设计需求提出了新的关注点,以此达到抑制数字接收机脉冲边沿镜像干扰的目的。     

北斗RDSS L腔体滤波器的应用设计

文章论述了基于北斗RDSS L腔体滤波器的应用设计,腔体滤波器用于抑制RDSS L功率放大器输出的带外杂散信号,避免带外杂散泄露到卫星导航接收通道工作带内导致导航接收机灵敏度恶化甚至不能正常工作。文章论述设计的三种腔体滤波器,可满足不同导航通信定位设备使用。     

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