实时时钟器件M41T94在配网监测终端中的应用

介绍具有SPI接口的多功能实时时钟器件M41T94,它具有精度高、功耗低等特点.提出一种M41T94在配网监测终端中的应用设计.结合单片机C8051F340的控制.给出配网监测终端实时时钟模块的软硬件设计.     

μPSD3251实时时钟的实现

引言实时时钟已被广泛应用于各种电子产品,为系统监控提供必要的时间信息。利用ST公司提供的多种类RTC芯片,用户可以在设计中方便地针对具体应用选择相应的芯片。本文讨论了实时时钟M41T0在μPSD3251系统中的应用、电路设计以及程序开发。     

配电网智能监测终端的设计与实现

随着智能配电技术的不断发展,配电网实时运行参数以及配电网电能质量已经成为众所关注的问题,为实现配电网实时运行情况的监测并对当前配电网的电能质量进行分析,本文提出了一种配电网智能监测终端的设计方法,详细介绍了智能监测终端的信号采集电路设计、数据存储设计、实时时钟设计、通信接口设计等。     

基于单片机的时钟电路设计

设计一种简易的时钟电路,电路由单片机最小系统、电平转换模块、按键输入模块,时钟模块、液晶显示模块组成.电路以STC89C52单片机为控制核心,控制串行实时时钟芯片M41ST85W进行时钟读、写、报警操作.     

μPSD3251实时时钟的实习

引言 实时时钟已被广泛应用于各种电子产品，为系统监控提供必要的时间信息。利用ST公司提供的多种类RTC芯片，用户可以在设计中方便地针对具体应用选择相应的芯片。本文讨论了实时时钟M41TO在μPSD3251系统中的应用、电路设计以及程序开发。     

配网自动化的典型解决方案

配网主站系统是整个配网自动化系统的核心，通过通信设备与终端没备联系，实现配网系统的实时监测控制、故障处理分析和管理等功能。iES—DMS1000系统是积成电子公司精心开发出来的一套集配网自动化与配网管理于一体的系统。该系统功能强大，结构清晰，技术先进成熟，运行稳定可靠，已有多家成功运行的先例。     

实时时钟芯片 M48T86 及其应用

M48T86是意法半导体公司（ST公司）生产的一种实时时钟/日历芯片。它具有精确计时、定时报警输出等功能，由于其内置128字节的非易失性RAM，因而具有功能强、使用方便等特点。文中详细介绍了M48T86的引脚功能，性能特点和主要参数，给出了其在检测系统中的应用电路和程序设计方法。     

配变终端在配网故障定位与快速复电应用研究

本文主要研究配变终端在配网故障定位与快速复电中的应用,首先对快速复电系统应用的现状进行介绍,重点分析配变监测计量终端故障定位技术,在此基础上深入研究快速复电系统系统设计实现.本文深度探索配变终端在配网故障定位与快速复电中的关键作用,也为后期更好地保障配网的供电可靠性提供参考.     

基于激光非线性成像技术的配网数字化作业安全远程红外监测系统

为准确识别配网数字化作业人员,提高配网数字化作业安全远程红外监测效果,研究基于激光非线性成像技术的配网数字化作业安全远程红外监测系统。系统的硬件设计为感知层、网络层、应用层和用户层4层,利用感知层的SF₆激光非线性摄像头采集配网数字化作业全过程红外图像,使用网络层的Internet将采集的图像传输到应用层;根据SF₆激光非线性摄像头结构和成像原理,设计配网数字化作业安全远程红外监测终端硬件结构;系统的软件部分,设计配网数字化作业安全远程红外监测流程;基于卷积神经网络算法搭建多尺度金字塔,提取作业人员特征图谱,通过快速局部拉普拉斯滤波变换增强图像的像素特征;基于Softmax函数识别配网数字化作业人员的危险区域侵入行为,实现配网数字化作业安全远程红外监测。试验结果表明：该系统的图像增强处理能力和作业人员识别效果较理想,并能及时、有效地预警作业人员的危险区侵入行为,预警用时始终低于0.06 s,且网络传输综合性能较为优异,数据丢包量最高为5 000个,提高了配网数字化作业安全远程红外监测效果。     

新型配电网故障指示器的设计

本文介绍了暂态零模电流相似性在单相接地故障定位中的应用,在此基础上设计了一种具有测量和通信功能的新型配电网故障指示器。该指示器不仅具有传统故障指示器的短路接地故障告警指示功能,还具有线路电流测量功能。测量数据以及故障告警信息通过无线射频方式传送给数据传输终端,数据传输终端通过GPRS将数据传送到配网自动化主站,从而实现配电线路的远程监测。     

基于径向波导合成技术的W波段功率放大器设计

基于径向波导合成技术,设计了一款W波段功率放大器。功放采用4路氮化镓单片微波集成电路(MMIC)单片合成设计,在90 GHz处输出功率为3.7 W,合成效率为94.3%,具有较好的工程应用价值。     

Holding State Performance Amelioration by Exploitation of NMOS Body Effect in 1T DRAM Cells

In this study curtailing of idle current in 1T1C and 1T1M DRAM cells by increasing threshold voltage during holding state is analyzed. This is attained by connecting the bulk to source in the active phases and pulling it below source potential throughout the holding phase. The proposed technique leads to body effect which affects the threshold voltage improving leakage current. The 1T1C and 1T1M discussed in this paper are volatile and non-volatile (memristor based) respectively. Memory design is fast becoming the pacemaker in the modern technology design which now requires DRAM cells with prolonged holding period and low idle power hence the need for lowering the leakage current. The dynamic nature of the 1T1C is due to charge leakage and the leakage current flowing through the 1T1M cell affects mem-resistance all this leading to state distortion. Idle current has of-late become one of the major contributors of power in large memory arrays in which in-active periods now dominates active period and by this technique idle power is reduced in both volatile and non-volatile cells. The proposed technique was implemented and simulations were done at different voltage levels at 45 nm technology. The method improved the leakage current, holding time and leakage power but at the expense of area and writing power.     

基于DSP的正弦永磁同步电机位置控制系统设计

本文介绍了以TMS320LF2407为核心的PMSM伺服控制装置设计,包括永磁同步电机的矢量控制方法,以及DSP及旋转变压器——数字转换器电路的硬件设计和积分分离PID、M／T法测速的软件设计方法。实验结果表明,该伺服装置达到了较高的速度／位置响应速度和控制精度。     

Design considerations for beamwaveguide in the NASA Deep SpaceNetwork

A generalized solution is found for retrofitting a large dual-shaped reflector antenna for a beamwaveguide. The design is termed as a bypass beamwaveguide. Both highpass design feed imaging and bandpass design feed imaging are considered. Each design was studied using geometrical optics, Gaussian wave analysis, and both low-frequency and high-frequency diffraction analysis. An important extension of the Mizusawa-Kitsuregawa criteria was discovered (M.M. Zusama and T. Kitsuregawa, ibid., vol.AP-21, pp.844-8, Nov. 1973). The principle revealed shows how a two-reflector cell, although in itself distorting, may be combined with a second cell which compensates for the first and delivers an output beam which is a good image of the input beam     

基于LTCC基板的X波段四通道T/R组件的设计

介绍了一种X波段四通道T/R组件的设计思路和实现方法。针对组件工作频率高、工作频段宽、通道数多、功能复杂、裸芯片多、重量要求严格等难点,组件采用低温共烧陶瓷设计、MCM设计、新型硅铝盒体材料设计等先进技术,成功研制出了低噪声、轻质量、功能齐全的小型化四通道T/R组件,该组件工作带宽在X波段达到2 GHz,发射功率达到+41 dBm,发射效率达到32%,接收噪声系数达到2.5～2.8 dB,移相精度达到20（RMS）,整体重量为96 g。组件已实现批量化生产。     

亚毫米波太赫兹集成天线测试系统及测试精度分析

集成天线代表了近年来天线技术的重大成就,为毫米波天线设计开辟了新思路。国内首套亚毫米波太赫兹集成天线测试系统由上海交通大学和中国电子科技集团第四十一研究所合作建成,该系统主要包括矢量网络分析仪、扩频模块、探针台、天线转台、控制机以及控制软件部分。能够在远场条件下完成18~325 GHz频率范围 内的片上天线的阻抗及辐射特性测试。文章介绍了系统框架原理,分析了影响系统测试精度的若干关键因素如系统底噪、探针辐射特性、探针阻抗特性、高密度泡沫载物台、吸波材料等对集成天线测试精度的影响,给出了系统可测增益的动态范围,最后测试了一款94 GHz片上集成天线,测试结果与仿真结果吻合良好。     

嵌入式微处理器与SDRAM的接口设计与实现

嵌入式微处理器与SDRAM存储器的接口设计是嵌入式开发系统中非常重要的一个环节。为了实现ARM与SDRAM的数据控制与传输,设计了以基于ARM920T内核的EP9315芯片与MT48LC4M3282TG接口,具体介绍了接口电路设计．EP9315对SDRAM的寻址逻辑,编程初始化SDRAM的实现,最后在硬件平台上调试成功。     

A sub-nanosecond resonant-type monolithic T/R switch formillimeter-wave systems applications

This paper is concerned with the design consideration, fabrication process, and performance of a V-band monolithic transmit/receive (T/R) switch for millimeter-wave wireless networks applications. The developed switch integrated circuit (IC) has a novel structure in which to pass a signal, it presents a parallel resonant circuit to the signal by forward biasing a pair of switching heterojunction FET's (HJFETs), but to block the signal, it presents a series resonant circuit to the signal by reverse biasing the switching HJFETs. With a control voltage of 0/3.2 V, the developed T/R switch exhibits a minimum insertion loss of 3.9 dB, a maximum isolation of 41 dB, and a high switching speed of 250 ps, over 57-61 GHz. The monolithic T/R switch chip size is 3.3 mm×1.7 mm     

An Improved Direct Digital Synthesizer Using Hybrid Wave Pipelining and CORDIC algorithm for Software Defined Radio

The improved Direct Digital Synthesizer (DDS) using the Hybrid Wave Pipelining (HWP) technique and COordinate Rotation DIgital Computer (CORDIC) algorithm for Software Defined Radio (SDR) is presented in this paper. In order to achieve high throughput, the hybrid wave pipelining technique is adopted. The HWP can be used to speed up the circuits without insertion of storage elements. The CORDIC algorithm is used for phase-to-amplitude conversion and utilized for dynamic transformation rather than Read Only Memory (ROM) static addressing. The frequency resolution and phase resolution are achieved as 0.023 Hz and 0.088 degree, respectively, at the maximum operating frequency of 199.288 MHz for the proposed DDS architecture. The spectral purity of the proposed design has been improved to 114 dBc with a throughput of 94 %. This paper is focused on the design and implementation of DDS using hybrid wave pipelining with CORDIC approach to target on Xilinx Spartan 3 (XC3S400-5PQ208) Field Programmable Gate Array (FPGA) with a speed grade of ?5. The proposed DDS design reduces the gate count from 49.4 % to 18.2 % as compared to the conventional pipelined Read Only Memory Look Up Table (ROMLUT) DDS method. The throughput of the proposed method has been improved from 78 % to 94 % and 55 % of total power reduction as compared with conventional DDS. The performance of the improved DDS architecture is compared with several existing DDS architectures and it is found that the present design is outperforming and can be used for software defined radios.     

A Jumping Genes Paradigm: Theory, Verification and Applications

A new evolutionary computing algorithm on the basis of "jumping genes" phenomenon is presented in this article. It emulates the gene transposition in the genome that was discovered by N obel Laureate D r. Barbara M cClintock from her work on maize chromosome. T he principle of jumping genes, adopted for evolutionary computing, is outlined and the procedures for executing the computational optimization are provided. M athematical derivation of the S chema Theorem is briefly discussed, which is established to demonstrate the searching capacity of the newly proposed algorithm, in terms of convergence and diversity. T he algorithm is found to be robust and provides outcomes in speed and accuracy, while the solutions are widely spread along the Pareto-optimal front when a multiobjective problem is tackled. T o further reinforce the jumping genes proposition, some typical engineering design problems are included. T he obtained results have indicated that this new algorithm is indeed capable of searching multiobjective solutions including the extreme solutions at both ends of the Pareto-optimal front.