为了能够满足基站易于选址、优质快速的建站要求和易维护、低成本、高可靠的运行要求，本文对以方舱来实现一体化结构基站做出一番探讨。从系统设计的观点阐述了移动通信高性能基站天线设计的几个关键问题，介绍了智能天线技术在基站中的应用，并且用HFSS软件仿真了一种新型的对称阵子天线，该天线驻波比小于2的带宽可以达到60%，具有良好的宽频带特性。 Abstract: In order to meet the station construction requirement of easy site selection and fast base station， and meet the operational requirement of easy maintenance， low cost and high reliability， this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design， the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS， the VSWR of the antenna is less than 2， and the bandwidth was reach to 60%. So it has good broadband properties.
上传时间： 2013-11-20
上传用户：linlin
阐述了轨道交通列车定位技术。介绍了在轨道交通系统中列车定位技术的功能，国内外轨道交通中主要采用的列车定位方法，重点论述了几种主要定位技术，并从定位精度、闭塞制式、维护投资成本、抗干扰等方面进行分析比较。提出目前轨道交通定位技术应综合运用，取长补短，多种方法相互融合，才能满足轨道交通中对安全可靠性的要求。 Abstract: Rail train positioning technology is described. The paper introduces the funetions of the train positioning technology in the rail transit system， the main methods of train positioning do mestic and international rail， and focuses on several key methods， analyzes and compares from the positioning accuracy， block system, maintenance and investment cost， interference and so on， suggested that the current rail positioning technology should be integrated use of positioning method of meriging， learn from each other， to meet the reliability requirements of rail safety.
上传时间： 2013-11-25
上传用户：franktu
针对UHF读写器设计中，在符合EPC Gen2标准的情况下，对标签返回的高速数据进行正确解码以达到正确读取标签的要求，提出了一种新的在ARM平台下采用边沿捕获统计定时器数判断数据的方法，并对FM0编码进行解码。与传统的使用定时器定时采样高低电平的FM0解码方法相比，该解码方法可以减少定时器定时误差累积的影响；可以将捕获定时器数中断与数据判断解码相对分隔开，使得中断对解码影响很小，实现捕获与解码的同步。通过实验表明，这种方法提高了解码的效率，在160 Kb/s的接收速度下，读取一张标签的时间约为30次/s。 Abstract: Aiming at the requirement of receiving correctly decoded data from the tag under high-speed communication which complied with EPC Gen2 standard in the design of UHF interrogator， the article introduced a new technology for FM0 decoding which counted the timer counter to judge data by using the edge interval of signal capture based on the ARM7 platform. Compared with the traditional FM0 decoding method which used the timer timed to sample the high and low level， the method could reduce the accumulation of timing error and could relatively separate capture timer interrupt and the data judgment for decoding， so that the disruption effect on the decoding was small and realizd synchronization of capture and decoding. Testing result shows that the method improves the efficiency of decoding， at 160 Kb/s receiving speed， the time of the interrogator to read a tag is about 30 times/s.
上传时间： 2013-11-10
上传用户：liufei
The information in this specification is subject to change without notice.Use of this specification for product design requires an executed license agreement from the CompactFlashAssociation.The CompactFlash Association shall not be liable for technical or editorial errors or omissions contained herein; norfor incidental or consequential damages resulting from the furnishing, performance, or use of this material.All parts of the CompactFlash Specification are protected by copyright law and all rights are reserved. Thisdocumentation may not, in whole or in part, be copied, photocopied, reproduced, translated, or reduced to anyelectronic medium or machine readable form without prior consent, in writing, from the CompactFlash Association.The CFA logo is a trademark of the CompactFlash Association.Product names mentioned herein are for identification purposes only and may be trademarks and/or registeredtrademarks of their respective companies.© 1998-99, CompactFlash Association. All rights reserved.
标签： 技术资料
上传时间： 2013-10-08
上传用户：stewart·
Agilent AN 154 S-Parameter Design Application Note S参数的设计与应用 The need for new high-frequency, solid-state circuitdesign techniques has been recognized both by microwaveengineers and circuit designers. These engineersare being asked to design solid state circuitsthat will operate at higher and higher frequencies.The development of microwave transistors andAgilent Technologies’ network analysis instrumentationsystems that permit complete network characterizationin the microwave frequency rangehave greatly assisted these engineers in their work.The Agilent Microwave Division’s lab staff hasdeveloped a high frequency circuit design seminarto assist their counterparts in R&D labs throughoutthe world. This seminar has been presentedin a number of locations in the United States andEurope.From the experience gained in presenting this originalseminar, we have developed a four-part videotape, S-Parameter Design Seminar. While the technologyof high frequency circuit design is everchanging, the concepts upon which this technologyhas been built are relatively invariant.The content of the S-Parameter Design Seminar isas follows:
标签： S参数
上传时间： 2013-12-19
上传用户：aa54
解压密码：www.elecfans.com 随着微电子技术的迅速发展以及集成电路规模不断提高，对电路性能的设计 要求越来越严格，这势必对用于大规模集成电路设计的EDA 工具提出越来越高的 要求。自1972 年美国加利福尼亚大学柏克莱分校电机工程和计算机科学系开发 的用于集成电路性能分析的电路模拟程序SPICE（Simulation Program with IC Emphasis）诞生以来，为适应现代微电子工业的发展，各种用于集成电路设计的 电路模拟分析工具不断涌现。HSPICE 是Meta-Software 公司为集成电路设计中 的稳态分析，瞬态分析和频域分析等电路性能的模拟分析而开发的一个商业化通 用电路模拟程序，它在柏克莱的SPICE（1972 年推出），MicroSim公司的PSPICE （1984 年推出）以及其它电路分析软件的基础上，又加入了一些新的功能，经 过不断的改进，目前已被许多公司、大学和研究开发机构广泛应用。HSPICE 可 与许多主要的EDA 设计工具，诸如Candence,Workview 等兼容，能提供许多重要 的针对集成电路性能的电路仿真和设计结果。采用HSPICE 软件可以在直流到高 于100MHz 的微波频率范围内对电路作精确的仿真、分析和优化。在实际应用中， HSPICE能提供关键性的电路模拟和设计方案，并且应用HSPICE进行电路模拟时， 其电路规模仅取决于用户计算机的实际存储器容量。 The HSPICE Integrator Program enables qualified EDA vendors to integrate their products with the de facto standard HSPICE simulator, HSPICE RF simulator, and WaveView Analyzer™. In addition, qualified HSPICE Integrator Program members have access to HSPICE integrator application programming interfaces (APIs). Collaboration between HSPICE Integrator Program members will enable customers to achieve more thorough design verification in a shorter period of time from the improvements offered by inter-company EDA design solutions.
上传时间： 2013-11-10
上传用户：123312
This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use.
上传时间： 2014-12-31
上传用户：PresidentHuang
It would not be an exaggeration to say that semiconductor devices have transformed humanlife. From computers to communications to internet and video games these devices and the technologies they have enabled have expanded human experience in a way that is unique in history. Semiconductor devices have exploited materials, physics and imaginative applications to spawn new lifestyles. Of course for the device engineer, in spite of the advances, the challenges of reaching higher frequency, lower power consumption, higher power generation etc.
上传时间： 2013-10-28
上传用户：songnanhua
This book evolved over the past ten years from a set of lecture notes developed while teaching the undergraduate Algorithms course at Berkeley and U.C. San Diego. Our way of teaching this course evolved tremendously over these years in a number of directions, partly to address our students' background (undeveloped formal skills outside of programming), and partly to reect the maturing of the eld in general, as we have come to see it. The notes increasingly crystallized into a narrative, and we progressively structured the course to emphasize the story line implicit in the progression of the material. As a result, the topics were carefully selected and clustered. No attempt was made to be encyclopedic, and this freed us to include topics traditionally de-emphasized or omitted from most Algorithms books.
标签： Algorithms 算法
上传时间： 2013-11-11
上传用户：JamesB
This example provides a description of how to use the USART with hardware flowcontrol and communicate with the Hyperterminal.First, the USART2 sends the TxBuffer to the hyperterminal and still waiting fora string from the hyperterminal that you must enter which must end by '\r'character (keypad ENTER button). Each byte received is retransmitted to theHyperterminal. The string that you have entered is stored in the RxBuffer array. The receivebuffer have a RxBufferSize bytes as maximum. The USART2 is configured as follow: - BaudRate = 115200 baud - Word Length = 8 Bits - One Stop Bit - No parity - Hardware flow control enabled (RTS and CTS signals) - Receive and transmit enabled - USART Clock disabled - USART CPOL: Clock is active low - USART CPHA: Data is captured on the second edge - USART LastBit: The clock pulse of the last data bit is not output to the SCLK pin
上传时间： 2013-10-31
上传用户：yy_cn
