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Radio-frequency

  • Radio Frequency Identification and Sensors

    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:shancjb

  • 射頻集成電路設(shè)計(jì)John Rogers(Radio Freq

    Radio Frequency Integrated Circuit Design I enjoyed reading this book for a number of reasons. One reason is that itaddresses high-speed analog design in the context of microwave issues. This isan advanced-level book, which should follow courses in basic circuits andtransmission lines. Most analog integrated circuit designers in the past workedon applications at low enough frequency that microwave issues did not arise.As a consequence, they were adept at lumped parameter circuits and often notcomfortable with circuits where waves travel in space. However, in order todesign radio frequency (RF) communications integrated circuits (IC) in thegigahertz range, one must deal with transmission lines at chip interfaces andwhere interconnections on chip are far apart. Also, impedance matching isaddressed, which is a topic that arises most often in microwave circuits. In mycareer, there has been a gap in comprehension between analog low-frequencydesigners and microwave designers. Often, similar issues were dealt with in twodifferent languages. Although this book is more firmly based in lumped-elementanalog circuit design, it is nice to see that microwave knowledge is brought inwhere necessary.Too many analog circuit books in the past have concentrated first on thecircuit side rather than on basic theory behind their application in communications.The circuits usually used have evolved through experience, without asatisfying intellectual theme in describing them. Why a given circuit works bestcan be subtle, and often these circuits are chosen only through experience. Forthis reason, I am happy that the book begins first with topics that require anintellectual approach—noise, linearity and filtering, and technology issues. Iam particularly happy with how linearity is introduced (power series). In therest of the book it is then shown, with specific circuits and numerical examples,how linearity and noise issues arise.

    標(biāo)簽: Rogers Radio John Freq

    上傳時(shí)間: 2014-12-23

    上傳用戶:han_zh

  • 無線電干擾 Radio Susceptibility

      Abstract: Engineers often wish that radio susceptibility (RS) or radio immunity could be cured with an antibiotic, a vaccine, or someform of cure-all. Unfortunately, solving the RS problem is not that easy. Indeed, the laws of physics apply. In this article we discusssources of RS. We also offer tips and hints to protect systems, power supplies, printed circuit boards (PCBs), and electroniccomponents from radio frequency interference.

    標(biāo)簽: Susceptibility Radio 無線電干擾

    上傳時(shí)間: 2014-12-30

    上傳用戶:旗魚旗魚

  • Advances+in+Mobile+Radio+Access+Networks

    This book gives a comprehensive overview of the technologies for the advances of mobile radio access networks. The topics covered include linear transmitters, superconducting filters and cryogenic radio frequency (RF) front head, radio over fiber, software radio base stations, mobile terminal positioning, high speed downlink packet access (HSDPA), multiple antenna systems such as smart antennas and multiple input and multiple output (MIMO) systems, orthogonal frequency division multiplexing (OFDM) systems, IP-based radio access networks (RAN), autonomic networks, and ubiquitous networks. 

    標(biāo)簽: Advances Networks Access Mobile Radio in

    上傳時(shí)間: 2020-05-26

    上傳用戶:shancjb

  • RFIC+Design+for+Cognitive+Radio+Systems

    Cognitive radios have become a vital solution that allows sharing of the scarce frequency spectrum available for wireless systems. It has been demonstrated that it can be used for future wireless systems as well as integrated into 4G/5G wireless systems. Although there is a great amount of literature in the design of cognitive radios from a system and networking point of view, there has been very limited available literature detailing the circuit implementation of such systems. Our textbook, Radio Frequency Integrated Circuit Design for Cognitive Radios, is the first book to fill a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems. In addition, this book describes several novel concepts that advance state-of-the-art cognitive radio systems.

    標(biāo)簽: Cognitive Systems Design Radio RFIC for

    上傳時(shí)間: 2020-06-01

    上傳用戶:shancjb

  • 超高頻射頻識(shí)別標(biāo)簽基準(zhǔn)測試研究.rar

    射頻識(shí)別(Radio Frequency Identification,RFID)是一種允許非接觸式數(shù)據(jù)采集的自動(dòng)識(shí)別技術(shù)。其中工作在超高頻(Ultra High Frequency,UHF)頻段的無源RFID系統(tǒng),由于在物流與供應(yīng)鏈管理等領(lǐng)域的潛在應(yīng)用,近年來得到了人們的廣泛關(guān)注。這種系統(tǒng)所使用的無源標(biāo)簽具有識(shí)別距離長、體積小、成本低廉等突出特點(diǎn)。目前在市場上出現(xiàn)了各種品牌型號(hào)的UHF RFID無源標(biāo)簽,由于不同品牌型號(hào)的標(biāo)簽在設(shè)計(jì)與制造工藝上的差異,這些標(biāo)簽在性能表現(xiàn)上各不相同,這就給終端用戶選擇合適自己應(yīng)用的標(biāo)簽帶來了困難。RFID基準(zhǔn)測試就是在實(shí)際部署RFID系統(tǒng)前對(duì)RFID標(biāo)簽的性能進(jìn)行科學(xué)評(píng)估的有效手段。然而為了在常規(guī)實(shí)驗(yàn)室條件下得到準(zhǔn)確公正的測試結(jié)果,需要對(duì)基準(zhǔn)測試的性能指標(biāo)及測試方法學(xué)開展進(jìn)一步的研究。本文正是研究符合EPC Class1 Gen2標(biāo)準(zhǔn)的RFID標(biāo)簽基準(zhǔn)測試。 本文首先分析了當(dāng)前廣泛應(yīng)用的超高頻無源RFID標(biāo)簽基準(zhǔn)測試性能指標(biāo)與測試方法上的局限性與不足之處。例如,在真實(shí)的應(yīng)用環(huán)境中,由于受到各種環(huán)境因素的影響,對(duì)同一品牌型號(hào)的標(biāo)簽,很難得到一致的識(shí)讀距離測試結(jié)果。另外,在某些測試場景中,使用識(shí)讀速率作為測試指標(biāo),所得到的測試結(jié)果數(shù)值非常接近,以致分辨度不足以區(qū)分不同品牌型號(hào)標(biāo)簽的性能差異。在這些分析基礎(chǔ)上,本文把路徑損耗引入了RFID基準(zhǔn)測試,通過有限點(diǎn)的測量與數(shù)據(jù)擬合分別得到不同類型標(biāo)簽的路徑損耗方程,結(jié)合讀寫器天線的輻射方向圖,進(jìn)一步得到各種標(biāo)簽受限于讀寫器接收靈敏度的覆蓋區(qū)域。無源標(biāo)簽由于其被動(dòng)式能量獲取方式,其實(shí)際工作區(qū)域仍然受限于前向鏈路。本文通過實(shí)驗(yàn)測試出這些標(biāo)簽的最小激活功率后,得出了各種標(biāo)簽在一定讀寫器發(fā)射功率下的激活區(qū)域。完成這些步驟后,根據(jù)這兩種區(qū)域的交集可以確定標(biāo)簽的工作區(qū)域,從而進(jìn)行標(biāo)簽間的比較并達(dá)到基準(zhǔn)測試的目的,并能找出限制標(biāo)簽工作范圍的瓶頸。 本文最后從功率損耗的角度研究了標(biāo)簽之間的相互干擾,為用戶在密集部署RFID標(biāo)簽的場景中設(shè)置標(biāo)簽之間的最小間隔距離具有重要的參考意義。

    標(biāo)簽: 超高頻 射頻識(shí)別 基準(zhǔn)測試

    上傳時(shí)間: 2013-04-24

    上傳用戶:hbsunhui

  • 基于FPGA的信道化中頻接收機(jī)設(shè)計(jì)與仿真實(shí)現(xiàn)研究.rar

    軟件無線電(Software Radio)具有高度靈活性、開放性,很容易實(shí)現(xiàn)與現(xiàn)有和未來多種電臺(tái)的兼容,能最大限度的滿足了互聯(lián)互通的要求。而基于多相濾波器組的信道化軟件無線電接收技術(shù)以其固有的全概率接收、降采樣速率以及其大幅提高運(yùn)算速率的能力越來越受到重視。本文主要研究了基于現(xiàn)場可編程門陣列(FPGA)的軟件無線電信道化中頻接收技術(shù)設(shè)計(jì)與實(shí)現(xiàn)。 首先介紹了軟件無線電的基本概念以及其發(fā)展?fàn)顩r,深入討論了軟件無線電的基本理論,主要介紹了設(shè)計(jì)中所用到的帶通采樣技術(shù)、信號(hào)的抽取技術(shù)與多相濾波技術(shù)。 然后簡要介紹了信道化中頻接收機(jī)的射頻(Radio Frequency,RF)前端接收技術(shù),設(shè)置寬中頻超外差接收機(jī)射頻前端的設(shè)計(jì)指標(biāo),給出了改進(jìn)的實(shí)信號(hào)濾波器組低通型實(shí)現(xiàn)結(jié)構(gòu),并依此推導(dǎo)和建立了實(shí)信號(hào)多相濾波器組信道化中頻接收機(jī)的數(shù)學(xué)模型。 最后基于EP1S80開發(fā)平臺(tái)實(shí)現(xiàn)了實(shí)信號(hào)多相濾波器組信道化的中頻接收機(jī)。給出了多相濾波器、抽取運(yùn)算、FFT運(yùn)算、信道劃分以及復(fù)乘運(yùn)算的設(shè)計(jì)方案。仿真結(jié)果表明,該接收機(jī)能夠?qū)崿F(xiàn)對(duì)中頻信號(hào)的正確接收,驗(yàn)證了系統(tǒng)設(shè)計(jì)的可行性。

    標(biāo)簽: FPGA 信道 中頻

    上傳時(shí)間: 2013-05-24

    上傳用戶:wyaqy

  • 基于ARM的915MHz射頻識(shí)別讀卡器研究

    射頻識(shí)別(RFID,Radio Frequency Identification)是一種利用電磁波雙向傳輸實(shí)現(xiàn)自動(dòng)識(shí)別的技術(shù)。近年來,射頻識(shí)別技術(shù)在物流、交通、身份識(shí)別等生產(chǎn)生活領(lǐng)域的應(yīng)用日益擴(kuò)大。相比于13.56MHz射頻識(shí)別系統(tǒng),915MHz射頻識(shí)別系統(tǒng)在識(shí)別距離,閱讀速度方面有更大的優(yōu)勢,是目前射頻識(shí)別產(chǎn)品研究的熱點(diǎn)。 本文在理解ISO/IEC18000-6C協(xié)議的基礎(chǔ)上,首先研究用于本系統(tǒng)的基本理論,包括射頻識(shí)別技術(shù)和嵌入式技術(shù),提出一款基于ISO/IEC18000-6C協(xié)議的915MHz射頻識(shí)別讀卡器的解決方案。在硬件部分,以Intel公司開發(fā)的R1000作為射頻收發(fā)模塊的核心;選用ATMEL公司的ARM處理器AT91SAM7S256作為控制單元的主控制器,在ARM處理器上運(yùn)行μC/OS-II嵌入式實(shí)時(shí)操作系統(tǒng),采用多任務(wù)實(shí)現(xiàn)和其他功能模塊的通信。軟件部分為系統(tǒng)移植了μC/OS-II操作系統(tǒng),使用C與匯編語言的混合編程編寫B(tài)ootloader,編寫了各種硬件設(shè)備的驅(qū)動(dòng)程序,使用C語言實(shí)現(xiàn)了串行通信程序,實(shí)現(xiàn)與上位機(jī)通信并實(shí)現(xiàn)對(duì)程序的更新。本文所設(shè)計(jì)的射頻識(shí)別系統(tǒng)具有模塊化設(shè)計(jì)、高可靠性等特點(diǎn)。實(shí)驗(yàn)表明,這種設(shè)計(jì)方案能夠達(dá)到ISO/IEC18000-6C協(xié)議要求。

    標(biāo)簽: ARM 915 MHz 射頻識(shí)別

    上傳時(shí)間: 2013-07-18

    上傳用戶:zklh8989

  • 基于ARM和Linux的超高頻讀寫器設(shè)計(jì)與實(shí)現(xiàn)

    UHF(Ultra High Frequency,超高頻)RFID(Radio Frequency Identification,射頻身份識(shí)別)技術(shù)是近幾年剛剛開始興起并得到迅速推廣應(yīng)用的一門新技術(shù)。該技術(shù)已被廣泛應(yīng)用于工業(yè)自動(dòng)化、商業(yè)自動(dòng)化、交通運(yùn)輸控制管理等眾多領(lǐng)域。但是,基于超高頻頻段讀寫器的研制在我國尚處于起步階段,傳統(tǒng)的超高頻讀寫器都是在單片機(jī)的基礎(chǔ)上實(shí)現(xiàn)的,這類讀寫器很難實(shí)現(xiàn)復(fù)雜的多任務(wù)功能;隨著經(jīng)濟(jì)的飛速發(fā)展,能夠與網(wǎng)絡(luò)互聯(lián)并且?guī)в胁僮飨到y(tǒng)的超高頻讀寫器越來越受人們的青睞與追求。針對(duì)這些問題,本文設(shè)計(jì)并實(shí)現(xiàn)了一種基于ARMS3C2410微處理器和Linux操作系統(tǒng)的超高頻讀寫器,主要內(nèi)容有: (1)分析了射頻識(shí)別技術(shù)的發(fā)展歷程和前景,以嵌入式技術(shù)為研究背景,結(jié)合軟硬件開發(fā)平臺(tái),給出了一種基于ARM和Linux的超高頻讀寫器設(shè)計(jì)思路,指出了選題研究的目的和意義。 (2)闡述了超高頻讀寫器的原理及其應(yīng)用,分析了讀寫器和標(biāo)簽之間進(jìn)行數(shù)據(jù)傳輸時(shí)所用到的相關(guān)技術(shù);在給出超高頻讀寫器主要技術(shù)性能指標(biāo)及功能要求的基礎(chǔ)上給出了基于ARMS3C2410和Linux超高頻讀寫器系統(tǒng)的總體設(shè)計(jì),同時(shí)對(duì)系統(tǒng)構(gòu)建過程中所用到的軟硬件進(jìn)行了器件選型。 (3)實(shí)現(xiàn)了超高頻讀寫器系統(tǒng)硬件電路的模塊設(shè)計(jì),主要包括主控電路模塊、存儲(chǔ)電路模塊、電源模塊、以太網(wǎng)模塊、液晶顯示模塊以及射頻收發(fā)模塊;闡述了各模塊的組成原理與實(shí)現(xiàn)方法,完成了硬件電路的原理圖繪制及PCB制板。 (4)根據(jù)系統(tǒng)的軟件需求,構(gòu)建了一個(gè)進(jìn)行嵌入式開發(fā)所需的軟件平臺(tái)。建立了交叉編譯環(huán)境以及NFS開發(fā)調(diào)試環(huán)境;移植了系統(tǒng)啟動(dòng)所需的引導(dǎo)程序bootloader;實(shí)現(xiàn)了嵌入式Linux操作系統(tǒng)內(nèi)核、文件系統(tǒng)的配置與移植;給出了Linux系統(tǒng)下典型設(shè)備(觸摸屏、網(wǎng)絡(luò)接口、LCD)驅(qū)動(dòng)程序的移植方法。 (5)結(jié)合實(shí)驗(yàn)測試環(huán)境,對(duì)超高頻讀寫器輸出功率,讀寫器發(fā)送命令以及標(biāo)簽應(yīng)答波形進(jìn)行了測試與分析;對(duì)讀寫器的整機(jī)性能進(jìn)行了聯(lián)機(jī)測試,給出了讀寫器系統(tǒng)的實(shí)際運(yùn)行效果圖,同時(shí)對(duì)測試結(jié)果進(jìn)行了總結(jié)。 實(shí)際應(yīng)用結(jié)果表明,基于ARMS3C2410微處理器和Linux操作系統(tǒng)的超高頻讀寫器能夠?qū)崿F(xiàn)接入網(wǎng)絡(luò)的功能,其讀寫速度、識(shí)別率以及識(shí)別距離等技術(shù)性能指標(biāo)均達(dá)到或優(yōu)于設(shè)計(jì)標(biāo)準(zhǔn)要求,該讀寫器在與PC機(jī)連接的情況下能進(jìn)行數(shù)據(jù)處理,樣機(jī)系統(tǒng)運(yùn)行穩(wěn)定可靠,達(dá)到了預(yù)期的設(shè)計(jì)目標(biāo)。

    標(biāo)簽: Linux ARM 超高頻 讀寫器

    上傳時(shí)間: 2013-07-25

    上傳用戶:saharawalker

  • 信道化中頻接收機(jī)設(shè)計(jì)與仿真實(shí)現(xiàn)

    軟件無線電(Software Radio)具有高度靈活性、開放性,很容易實(shí)現(xiàn)與現(xiàn)有和未來多種電臺(tái)的兼容,能最大限度的滿足了互聯(lián)互通的要求。而基于多相濾波器組的信道化軟件無線電接收技術(shù)以其固有的全概率接收、降采樣速率以及其大幅提高運(yùn)算速率的能力越來越受到重視。本文主要研究了基于現(xiàn)場可編程門陣列(FPGA)的軟件無線電信道化中頻接收技術(shù)設(shè)計(jì)與實(shí)現(xiàn)。 首先介紹了軟件無線電的基本概念以及其發(fā)展?fàn)顩r,深入討論了軟件無線電的基本理論,主要介紹了設(shè)計(jì)中所用到的帶通采樣技術(shù)、信號(hào)的抽取技術(shù)與多相濾波技術(shù)。 然后簡要介紹了信道化中頻接收機(jī)的射頻(Radio Frequency,RF)前端接收技術(shù),設(shè)置寬中頻超外差接收機(jī)射頻前端的設(shè)計(jì)指標(biāo),給出了改進(jìn)的實(shí)信號(hào)濾波器組低通型實(shí)現(xiàn)結(jié)構(gòu),并依此推導(dǎo)和建立了實(shí)信號(hào)多相濾波器組信道化中頻接收機(jī)的數(shù)學(xué)模型。 最后基于EP1S80開發(fā)平臺(tái)實(shí)現(xiàn)了實(shí)信號(hào)多相濾波器組信道化的中頻接收機(jī)。給出了多相濾波器、抽取運(yùn)算、FFT運(yùn)算、信道劃分以及復(fù)乘運(yùn)算的設(shè)計(jì)方案。仿真結(jié)果表明,該接收機(jī)能夠?qū)崿F(xiàn)對(duì)中頻信號(hào)的正確接收,驗(yàn)證了系統(tǒng)設(shè)計(jì)的可行性。

    標(biāo)簽: 信道 中頻 仿真實(shí)現(xiàn) 收機(jī)設(shè)計(jì)

    上傳時(shí)間: 2013-06-12

    上傳用戶:qq521

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