Ku波段收发组件设计分析

该Ku波段收发组件包括发射双通道上变频和接收下变频两部分内容。双通道上变频模块包括本振、上变频器、滤波器、放大器、耦合器、隔离器、开关等。双通道上变频模块的发射通路具有耦合输出,可以接到接收通道耦合输入,用来形成发射通道与接收通道的自闭环,完成系统自检测试功能。下变频通道前端主要由低噪声放大器、耦合器、混频器以及中频滤波和放大器组成。     

新产品：东方联星公司多模兼容芯片抱眼年会

受大会邀请,东方联星公司张峻林总经理对“多模兼容芯片技术”作了特别报告。报告充分向大家展示了该公司已经批量生产和应用的北斗多模卫星导航芯片,以该款芯片为核心的卫星导航接收机,可以同时接收北斗二号、GPS、GLONASS卫星信号,具有北斗、GPS或GLONASS单星座定位、北斗／GPS双星座联合定位、北斗／GLONASS双星座联合定位、北斗／GPS／GLONASS三星座联合定位的能力。     

北斗RDSS芯片在北斗终端的应用

广嘉电子针对北斗射频单元开发的BG—DB-2416CX射频芯片（北斗RDSS射频芯片）,通过片外少许的元件即实现北斗一代射频信号的接收和发射功能。芯片实现了集成接收通道和发射通道,并集成了接收发射频率综合器,接收通道采用两次变频结构,首先把射频信号下变频到第一中频,然后再通过正交混频器产生最终的正交中频信号12．24MHZ。发射通道采用直接调制结构,可直接处理TTL电平输入信号,调制到所需载波频率处,完成发射功能。     

合众思壮 构建中国位置，北斗无所不在

日前．北京合众思壮科技股份有限公司携系列北斗产品亮“相第三届中国卫星导航学术年会”．中国科学院院士、国际宇航科学院院士孙家栋等嘉宾到合众思壮展台参观。合众思壮参展主题为：“构建中国位置,北斗无所不在”,展示的产品包括双系统（北斗／GPS）定位模块、三系统（北斗／GPS／GLONASS）芯片、双系统板卡（包括卫星接收及高精度授时）、三系统卫星接收板卡、双系统车载导航终端、双系统手持机、北斗车载行驶记录仪、高精度测姿终端、北斗信号模拟与功率检测一体机、北斗航空型多频天线等十余款北斗核心部件与终端产品。     

英飞凌全新接收前端模块系列现已问世

面向GPS和GLONASS应用 英飞凌科技近日宣布推出确保智能手机和其他移动终端实现全球导航卫星系统（GNSS）功能的全新接收前端模块系列。新型BGM103xN7系列器件是首批支持全球定位系统（GPS）和全球导航卫星系统（GLONASS）信号的独立或同步接收的模块。     

GPS射频信号源的设计与实现

在研究GPS信号结构的基础上,给出了GPS射频信号源的设计方案,并分模块进行了设计与实现.实验结果表明,基带/中频模块实现了GPS信号的BPSK调制和扩频调制,输出数字中频信号;射频模块实现了上变频功能,完成了信号的射频调制.     

浅析ECM微波通道信号质量在设计和生产中的控制要素

目前ECM系统中,大多采用先将输入的射频信号下变频,再将中频存储后上变频并放大发射的体制。从ECM系统微波通道原理出发,定性分析了影响整个通道信号质量的主要因素变频本振、变频器隔离度、发射装置输入信号与发射装置之间的信号强度匹配以及通道的寄生信号,在此基础上提出了在ECM系统设计和生产过程中需要控制的要素。     

新型北斗用户机射频模块设计

为减小北斗用户机的体积,降低终端成本,缩短终端系统调试时间,文中采用北斗卫星导航系统专用射频芯片,设计了一款新型的北斗用户机模块。该模块体积仅为27mm×19mm。调试后的测试结果为：接收通道噪声系数小于4．5dB,AGC（自动增益控制）范围大于55dB,中频输出幅度为峰峰值1V,输入驻波比小于1．5;发射通道功率调整范围达到-10dBm～5dBm,输出1dB压缩点大于10dBm,本振抑制大于30dB,本振相位噪声误差小于0．9°。测试结果表明射频模块性能全部满足整机要求。     

一种UHF波段8通道数字阵列模块设计

介绍了采用高精度数字延时补偿和一次有源混频方式的UHF波段8通道数字阵列模块,其内部集成8个相互独立的模拟收发通道、8通道数字接收、8通道数字波形产生,以及本振功分器、时钟分配器、分布式电源、数据传输和光电转换等部分,其单通道发射输出脉冲峰值功率大于180W,脉内信噪比大于55d B,脉冲顶降小于1d B,接收噪声系数小于2.0d B,接收信噪比大于55d B,通道间隔离度大于30d B。该数字阵列模块集成度高、接口简洁、性能稳定、环境适应能力强、可靠性高,现已批量应用于某远程预警相控阵雷达。     

系统级封装的S频段射频收发模块研制

研制了一种小体积的S频段射频收发系统级封装( SIP)模块,内部集成了基于多种工艺的器件。模块接收通道一次变频,发射通道二次变频,内部集成中频和射频本振信号源。模块采用双腔结构,不同腔体之间通过绝缘子进行垂直互连,大大减小了模块体积,模块体积为40 mm×40 mm×10 mm。模块采用正向设计,其主要指标的测试结果为：接收通道动态范围-100~-40 dBm,输出信号0~2 dBm,噪声系数小于等于2.8 dB,带外抑制大于等于50 dBc;发射通道输出信号大于等于2 dBm,二次、三次谐波抑制大于等于60 dBc,杂波抑制大于等于55 dBc,相位噪声在1 kHz和10 kHz处分别小于等于-82 dBc/Hz和-91 dBc/Hz。实测结果与仿真结果基本一致。     

Building a in a flash supercomputer

A flash mob is a group of strangers, organized over the Internet, that comes together briefly, acts out a predetermined scenario-often something as simple as clapping for 30 seconds-and then disperses. A supercomputer is a very fast and powerful computer that outperforms most mainframes, at a cost, typically, of millions of dollars. Can a flash mob build a supercomputer? It can sure try, and so it did on 3 April at the University of San Francisco's Koret athletic center. The goal was to run the Linpack benchmark, a standard method of assessing the speed of supercomputers, to achieve a speed of at least 403 gigaflops (billion floating point operations per second). This would be fast enough to earn the system a place on the list of the world's fastest 500 supercomputers. The goal was not reached. The group reached just 180 gigaflops before it was time to pack up the computers and go home. However, even though the San Francisco effort fell short of speed goal, it did ignite imaginations.     

一年之间，物换星移

去年的这个时候,供货商们还在为生存而挣扎。如今,2009年的年报已经公布,许多供应商的年报业绩之好,就连最乐观的分析师也始料未及。这种变化的原因很简单：供应商们大幅削减成本,接下来是强劲的需求,这又导致了随后高企的设备利用率。     

On a wing and a prayer

Aircraft giants Boeing and Airbus are pinning their hopes on very different visions of how air travel will evolve in the coming decade.     

Cooperative control of a human and a robot manipulator for positioning a cart on a frictionless plane

Robots may be expected to execute some tasks in cooperation with humans. Control systems for such robots should be appropriate to adapt to human characteristics in order to successfully accomplish the task. Pushing a cart on a frictionless plane in cooperation with a human is a basic example to such a task. To control the motion of an object from one point to another on a frictionless plane is impossible by only pushing in one direction without supporting it in the opposite direction, since as soon as the force is applied, the object will move without stopping its motion. In this paper, compliant cooperative positioning of a cart on a frictionless plane by a human and a manipulator is proposed using impedance control method with the parameters obtained from human–human cooperation.     

基于智能手机压电基片上微液滴位置分析章

为了降低微流分析成本,该文提出了基于智能手机检测压电基片上目标微液滴方法,并开发出相应的应用软件,通过分析微液滴颜色信息和几何信息定位目标微液滴位置,结合分析时间获取微液滴输运速度。为验证提出方法的正确性,以5 μL黑色墨水溶液微液滴为研究对象,进行压电基片上微液滴识别和位置分析实验。结果表明,该文所提方法和开发的应用软件可识别和定位压电基片上微液滴,在功率为27.5 dBm时,第2~10 s段内微液滴输运速度为0.416 mm/s。     

Analysis of a coaxial-to-waveguide adaptor including a discendedprobe and a tuning post

A field matching analysis of a coaxial-to-waveguide adaptor incorporating a disc-ended probe and a tuning post is presented. In this analysis, the tuning post is considered as a short-circuited second probe. A computer algorithm for calculating the input impedance of this structure is developed. This algorithm is used to investigate and improve the operation of a commercially available coaxial-to-waveguide adaptor     

Transmission-Line Properties of a Strip on a Dielectric Sheet on a Plane

The subject is a strip Iine formed of a strip and a parallel ground plane separated by a dielectric sheet (commonly termed "microstrip"). Building on the author's earlier papers all the significant properties are formulated in explicit form for practical applications. This may mean synthesis and/or analysis. Each formula is a close approximation for all shape ratios, obtained by a gradual transition between theoretical forms for the extremes of narrow and wide strips. The effect of thickness is formulated to a second-order approximation. Then the result is subjected to numerical differentiation for simple evaluation of the magnetic-loss power factor from the skin depth. The transition formulas are tested against derived formulas for overlapping narrow and wide ranges of shape. Some of these formulas are restated from the earlier derivations and others are derived herein. The latter include the second-order approximation for a narrow thin strip, and a close approximation for a narrow or wide square cross section in comparison with a circular cross section. Graphs are given for practical purposes, showing the wave resistance and magnetic loss for a wide range of shape and dielectric. For numerical reading, the formulas are suited for programming on a digital pocket calculator.     

构建完整工业ADC接口的微控制器和调制器

设计师们通常使用0mA～20mA和0V～10V的隔离输入作为工业应用控制的信号.由隔离电源、Analog Devices AD7400调制器内置隔离及TexasInstruments MSP430微控制器共同为工业设计师要求的一种完整、隔离且可靠的模拟信号接口创建一种设计.