Identification is pervasive nowadays in daily life due to many complicated activities such as bank and library card reading, asset tracking, toll collecting, restricted access to sensitive data and procedures and target identification. This kind of task can be realized by passwords, bio- metric data such as fingerprints, barcode, optical character recognition, smart cards and radar. Radiofrequencyidentification(RFID)isatechniquetoidentifyobjectsbyusingradiosystems. It is a contactless, usually short distance, wireless data transmission and reception technique for identification of objects. An RFID system consists of two components: the tag (also called transponder) and the Reader (also called interrogator).
標(biāo)簽： Processing Digital Signal RFID for
上傳時(shí)間： 2020-06-08
上傳用戶(hù)：shancjb
There is an unprecedented enthusiasm for radio frequency identification (RFID) technologies today. RFID is based on the exchange of information carried by electromagnetic waves between a label, or tag, and a Reader. This technology is currently in full economic expansion, which has manifested itself in widely backed research activities, some of which will be examined in this book.
標(biāo)簽： Identification Frequency Sensors Radio and
上傳時(shí)間： 2020-06-08
上傳用戶(hù)：shancjb
We are in the era of ubiquitous computing in which the use and development of Radio Frequency Iden- tification (RFID) is becoming more widespread. RFID systems have three main components: Readers, tags, and database. An RFID tag is composed of a small microchip, limited logical functionality, and an antenna. Most common tags are passive and harvest energy from a nearby RFID Reader. This energy is used both to energize the chip and send the answer back to the Reader request. The tag provides a unique identifier (or an anonymized version of that), which allows the unequivocal identification of the tag holder (i.e. person, animal, or items).
標(biāo)簽： Identification Wireless
上傳時(shí)間： 2020-06-08
上傳用戶(hù)：shancjb
If one examines the current literature on GPS receiver design, most of it is quite a bit above the level of the novice. It is taken for granted that the Reader is already at a fairly high level of understanding and proceeds from there. This text will be an attempt to take the Reader through the concepts and circuits needed to be able to understand how a GPS receiver works from the antenna to the solution of user position.
標(biāo)簽： Fundamentals_of_Global_Positionin g_System
上傳時(shí)間： 2020-06-09
上傳用戶(hù)：shancjb
Fun. We (your authors) wanted a word to describe our ultimate goal for this book, as well as a word we hope you (our Reader) will use to describe it, and that’s the one we chose. There are others goals, of course, but in the end, when you’ve finished the book, we’re hoping you’ll have enjoyed the activities described in these pages. Many books use the Introduction to explain exactly what the book is about, what the Reader will learn, what the Reader needs (a skill or maybe an item or piece of software), and what the Reader will be left with when that last page is completed. And this Introduction will do those things, but … hopefully it’ll make you excited to get started.
標(biāo)簽： Adventures Arduino Station Escape Gemini from
上傳時(shí)間： 2020-06-09
上傳用戶(hù)：shancjb
I wrote this book so that students, hobbyists, and engineers alike can take advantage of the Arduino platform by creating several projects that will teach them about the engineering process. I also wanted to guide the Reader through introductory projects so that they could get a firm grasp on the Arduino Language, and how to incorporate several pieces of hardware to make their own projects. This book offers so much information on the Arduino, not just the basic LED projects but it offers different peripherals such as Ultrasonic sensor, the Xbox? controller, Bluetooth, and much more. This book also teaches the non-engineer to follow a process that will help them in future project (not just Arduino projects).
標(biāo)簽： Engineering Practical Arduino
上傳時(shí)間： 2020-06-09
上傳用戶(hù)：shancjb
The countless technological advances of the twentieth century require that futureengineering educationemphasizebridging thegapbetweentheoryand the real world.Thisedition hasbeenprepared withparticular attentiontothe needs of undergraduates, especially those who seek a solid foundation in control theory aswellas an ability tobridgethe gapbetween control theory and itsreal- world applications.To help the Reader achieve this goal, computer-aided design accuracy checks (CADAC) are used throughout the text to encourage good habits of computerliteracy.Each CADAC uses fundamentalconcepts to ensure the viability of a computer solution.
標(biāo)簽： Analysis Control Linear Design System Fifth and
上傳時(shí)間： 2020-06-10
上傳用戶(hù)：shancjb
? 如果 PCB 用排線(xiàn)連接，控制排線(xiàn)對(duì)應(yīng)的插頭插座必須成直線(xiàn)，不交叉、不扭曲。 ? 連續(xù)的 40PIN 排針、排插必須隔開(kāi) 2mm 以上。 ? 考慮信號(hào)流向，合理安排布局，使信號(hào)流向盡可能保持一致。 ? 輸入、輸出元件盡量遠(yuǎn)離。 ? 電壓的元器件應(yīng)盡量放在調(diào)試時(shí)手不易觸及的地方。 ? 驅(qū)動(dòng)芯片應(yīng)靠近連接器。 ? 有高頻連線(xiàn)的元件盡可能靠近，以減少高頻信號(hào)的分布參數(shù)和電磁干擾。 ? 對(duì)于同一功能或模組電路，分立元件靠近芯片放置。 ? 連接器根據(jù)實(shí)際情況必須盡量靠邊放置。 ? 開(kāi)關(guān)電源盡量靠近輸入電源座。 ? BGA 等封裝的元器件不應(yīng)放于 PCB 板正中間等易變形區(qū) ? BGA 等陣列器件不能放在底面， PLCC 、 QFP 等器件不宜放在底層。 ? 多個(gè)電感近距離放置時(shí)應(yīng)相互垂直以消除互感。 ? 元件的放置盡量做到模塊化并連線(xiàn)最短。 ? 在保證電氣性能的前提下，盡量按照均勻分布、重心平衡、版面美觀的標(biāo)準(zhǔn)優(yōu)化布局。 ? 按電路模塊進(jìn)行布局，實(shí)現(xiàn)同一功能的相關(guān)電路稱(chēng)為一個(gè)模塊，電路模塊中的元件應(yīng)采用就近集 中原則，同時(shí)數(shù)字電路和模擬電路分開(kāi)； ? 定位孔、標(biāo)準(zhǔn)孔等非安裝孔周?chē)? 1.27mm 內(nèi)不得貼裝元、器件，螺釘?shù)劝惭b孔周?chē)? 緊固件安裝孔、橢圓孔及板中其它方孔外側(cè)距板邊的尺寸大于 3mm ； ? 發(fā)熱元件不能緊鄰導(dǎo)線(xiàn)和熱敏元件；高熱器件要均衡分布；
標(biāo)簽： pcb 設(shè)計(jì)規(guī)范
上傳時(shí)間： 2021-06-25
上傳用戶(hù)：xiangshuai
為了提高超高頻RFID系統(tǒng)中閱讀器在低信噪比的情況下仍具有較高的識(shí)別能力,提出一種基于FPGA系統(tǒng)結(jié)合軟件無(wú)線(xiàn)電方法實(shí)現(xiàn)超高頻RFID射頻前端電路方案。超高頻射頻識(shí)別系統(tǒng)必須符合EPC Class 1generation 2標(biāo)準(zhǔn),所設(shè)計(jì)的電路系統(tǒng)以Xilinx公司的XC6SLX16-2CSG324FPGA芯片為硬件基礎(chǔ),將數(shù)字基帶調(diào)制解調(diào)和中頻濾波電路在FPGA系統(tǒng)中設(shè)計(jì)實(shí)現(xiàn),重點(diǎn)闡述了射頻前端電路的設(shè)計(jì)結(jié)構(gòu)、AD/DA轉(zhuǎn)換電路,以及數(shù)字濾波器的設(shè)計(jì)。實(shí)驗(yàn)結(jié)果表明,所設(shè)計(jì)的超高頻RFID閱讀器簡(jiǎn)化了前端電路系統(tǒng)結(jié)構(gòu),提升了穩(wěn)定性,增強(qiáng)了抗干擾能力。該電路系統(tǒng)在信噪比較低的情況下,能夠較好地實(shí)現(xiàn)915MHz頻率的射頻接收和發(fā)送。In order to improve the Reader UHF RFID system still has a higher ability to identify,in the case of low signal-to-noise ratio.The UHF RFID systems must comply with EPC Class 1 generation 2 standard.In this paper,the design of the circuit system based on Xilinx＇s XC6SLX16-2CSG324 FPGA chip,and presents UHF RFID RF front-end circuit with software radio based on FPGA system.Digital baseband modem and IF filter circuit is designed and implemented in the FPGA system,and focused on designing the structure of the RF front-end circuit,AD/DA conversion circuits,and digital filter.Experimental results show that the UHF RFID Reader de...
標(biāo)簽： 915mhz 超高頻 rfid 閱讀 射頻 前端 電路 設(shè)計(jì)
上傳時(shí)間： 2022-04-17
上傳用戶(hù)：shjgzh
說(shuō)明： 51單片機(jī)控制fm1702射頻讀卡芯片讀寫(xiě)mifare1卡全套資料。包括電路圖，pcb板圖，上、下位機(jī)軟件及源碼，stc單片機(jī)下載軟件，各種資料文檔等。(51 SCM control fm1702 RF Reader chip card Reader mifare1 a full set of data. Including the circuit diagram, pcb board map, the upper and lower-bit machine software and source code, stc SCM download software, all kinds of information documentation.)
標(biāo)簽： 51單片機(jī) fm1702 射頻芯片
上傳時(shí)間： 2022-05-27
上傳用戶(hù)：
蟲(chóng)蟲(chóng)下載站版權(quán)所有 京ICP備2021023401號(hào)-1
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