半導(dǎo)體的產(chǎn)品很多，應(yīng)用的場合非常廣泛，圖一是常見的幾種半導(dǎo)體元件外型。半導(dǎo)體元件一般是以接腳形式或外型來劃分類別，圖一中不同類別的英文縮寫名稱原文為 PDID：Plastic Dual Inline Package SOP：Small Outline Package SOJ：Small Outline J-Lead Package PLCC：Plastic Leaded Chip Carrier QFP：Quad Flat Package PGA：Pin Grid Array BGA：Ball Grid Array 雖然半導(dǎo)體元件的外型種類很多，在電路板上常用的組裝方式有二種，一種是插入電路板的銲孔或腳座，如PDIP、PGA，另一種是貼附在電路板表面的銲墊上，如SOP、SOJ、PLCC、QFP、BGA。 從半導(dǎo)體元件的外觀，只看到從包覆的膠體或陶瓷中伸出的接腳，而半導(dǎo)體元件真正的的核心，是包覆在膠體或陶瓷內(nèi)一片非常小的晶片，透過伸出的接腳與外部做資訊傳輸。圖二是一片EPROM元件，從上方的玻璃窗可看到內(nèi)部的晶片，圖三是以顯微鏡將內(nèi)部的晶片放大，可以看到晶片以多條銲線連接四周的接腳，這些接腳向外延伸並穿出膠體，成為晶片與外界通訊的道路。請注意圖三中有一條銲線從中斷裂，那是使用不當(dāng)引發(fā)過電流而燒毀，致使晶片失去功能，這也是一般晶片遭到損毀而失效的原因之一。 圖四是常見的LED，也就是發(fā)光二極體，其內(nèi)部也是一顆晶片，圖五是以顯微鏡正視LED的頂端，可從透明的膠體中隱約的看到一片方型的晶片及一條金色的銲線，若以LED二支接腳的極性來做分別，晶片是貼附在負極的腳上，經(jīng)由銲線連接正極的腳。當(dāng)LED通過正向電流時，晶片會發(fā)光而使LED發(fā)亮，如圖六所示。 半導(dǎo)體元件的製作分成兩段的製造程序，前一段是先製造元件的核心─晶片，稱為晶圓製造；後一段是將晶中片加以封裝成最後產(chǎn)品，稱為IC封裝製程，又可細分成晶圓切割、黏晶、銲線、封膠、印字、剪切成型等加工步驟，在本章節(jié)中將簡介這兩段的製造程序。
上傳時間： 2013-11-04
上傳用戶：372825274
ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and noise are important performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
上傳時間： 2013-11-02
上傳用戶：maricle
Blind Equalizer 的演算法主要是利用CMA及 LMS 的配合，當(dāng)CMA將EYE打開，使訊號趨近于正確值，就切換到LMS，利用Slicer的輸出當(dāng)作training sequence來調(diào)整Equalizer的系數(shù)，而Carrier Recovery 的部份，則是將phase error track出來
上傳時間： 2013-12-28
上傳用戶：it男一枚
Simulation of a transmitter implementingthe OFDM transmission chain with QPSK modulation on each sub-carrier
標簽： implementingthe transmission transmitter Simulation
上傳時間： 2013-12-23
上傳用戶：cainaifa
This paper examines the asymptotic (large sample) performance of a family of non-data aided feedforward (NDA FF) nonlinear least-squares (NLS) type carrier frequency estimators for burst-mode phase shift keying (PSK) modulations transmitted through AWGN and flat Ricean-fading channels. The asymptotic performance of these estimators is established in closed-form expression and compared with the modified Cram`er-Rao bound (MCRB). A best linear unbiased estimator (BLUE), which exhibits the lowest asymptotic variance within the family of NDA FF NLS-type estimators, is also proposed.
標簽： performance asymptotic examines non-data
上傳時間： 2015-12-30
上傳用戶：225588
在DAB系統(tǒng)中的頻率同步，載頻同步，參考一下Carrier frequency offset estimation of DAB receiver based on phase reference symbol
上傳時間： 2014-11-23
上傳用戶：songrui
數(shù)字圖像處理基礎(chǔ)理論，英文資料Restoration and Enhancement Space Pictures (blurred, noisy, distorted) Computerized Tomography Coding Transmission – Teleconferencing Storage – Land SAT Images Pattern Recognition Blood Cell Analysis Remote Sensing Robotic Vision Computer Graphics Flight Simulation Auto Body Design Special Effect in Movie
標簽： 數(shù)字圖像處理
上傳時間： 2014-06-30
上傳用戶：plsee
X10 Protocol.pdf X10 Home Automation.pdf Microchip - AN236 - Home automation using X10.pdf MANDO UNIVERSAL X10 WIRELESS MOUSE REMOTE SYSTEM.pdf Manual ipcontrol x10.pdf x10_camera_control_system.doc domotica d-6006 - X10.pdf X10 Temperature Sensing Device.pdf DOMOTICA X10.pdf Switching Lights With X10 Controllers.pdf X10 iwitness.pdf protocol X10.pdf codelist mando universal x10.pdf x10.rtf
標簽： Home Automation automation
上傳時間： 2013-12-06
上傳用戶：zhuyibin
Abstract—Wireless networks in combination with image sensors open up a multitude of previously unthinkable sensing applications. Capable tools and testbeds for these wireless image sensor networks can greatly accelerate development of complex, yet efficient algorithms that meet application requirements. In this paper, we introduce WiSNAP, a Matlab-based application development platform intended for wireless image sensor networks. It allows researchers and developers of such networks to investigate, design, and evaluate algorithms and applications using real target hardware. WiSNAP offers standardized and easy-to-use Application Program Interfaces (APIs) to control image sensors and wireless motes, which do not require detailed knowledge of the target hardware. Nonetheless, its open system architecture enables support of virtually any kind of sensor or wireless mote. Application examples are presented to illustrate the usage of WiSNAP as a powerful development tool.
標簽： combination previously multitude Abstract
上傳時間： 2013-12-03
上傳用戶：D&L37
In this paper we describe a control methodology for catching a fast moving object with a robot manipulator, where visual information is employed to track the trajectory of the target. Sensing, planning and control are performed in real-time to cope with possible unpredictable trajectory changes of the moving target, and prediction techniques are adopted to compensate the time delays introduced by visual processing and by the robot controller. A simple but reliable model of the robot controller has been taken into account in the control architecture for improving the performance of the system. Experimental results have shown that the robot system is capable of tracking and catching an object moving on a plane at velocities of up to 700 mm/s and accelerations of up to 1500 mm/s2.
標簽： methodology describe catching control
上傳時間： 2014-01-12
上傳用戶：qq521
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