• PUDN用户
  • LabView
  • 4.9MB
  • rar
  • 0
  • 1 积分
  • 7
  • 2012-04-16 09:15
  • am_modulation.vi
  • am_modulation.doc
<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/622b6d7215da9b288bc05aad/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622b6d7215da9b288bc05aad/bg1.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x1 h3 y2 ff1 fs0 fc0 sc0 ls0 ws0">RF<span class="_ _0"></span> Simulation Demo: <span class="_ _1"></span>Amplitude </div><div class="t m0 x1 h3 y3 ff1 fs0 fc0 sc0 ls0 ws0">Modulation</div><div class="t m0 x1 h4 y4 ff2 fs1 fc0 sc0 ls0 ws0">3 <span class="ff3">&#35780;&#32423;</span> | <span class="ff1">2.67</span> out of 5</div><div class="t m0 x2 h4 y5 ff3 fs1 fc1 sc0 ls0 ws0">&#25171;&#21360;<span class="ff2 fc0"> </span></div><div class="t m0 x1 h5 y6 ff3 fs2 fc0 sc1 ls0 ws0">&#27010;&#35272;</div><div class="t m0 x1 h6 y7 ff2 fs1 fc0 sc0 ls0 ws0">Modulation is a process by which characteristics of a high-frequency carrier signal<span class="_ _2"></span> are </div><div class="t m0 x1 h6 y8 ff2 fs1 fc0 sc0 ls0 ws0">altered to convey information contained in a lower-frequency message.<span class="_ _2"></span> Though it is </div><div class="t m0 x1 h6 y9 ff2 fs1 fc0 sc0 ls0 ws0">theoretically possible to transmit baseband signals (or information) without modulating </div><div class="t m0 x1 h6 ya ff2 fs1 fc0 sc0 ls0 ws0">the data, it is far more efficient to send messages by modulating<span class="_ _2"></span> the information onto a </div><div class="t m0 x1 h6 yb ff2 fs1 fc0 sc0 ls0 ws0">carrier wave. High frequency waveforms require smaller antennae<span class="_ _2"></span> for reception, </div><div class="t m0 x1 h6 yc ff2 fs1 fc0 sc0 ls0 ws0">efficiently use available bandwidth, and are flexible enough to carry different types<span class="_ _2"></span> of </div><div class="t m0 x1 h6 yd ff2 fs1 fc0 sc0 ls0 ws0">data. There are a variety of modulation schemes available<span class="_ _2"></span> for both analog and digital </div><div class="t m0 x1 h6 ye ff2 fs1 fc0 sc0 ls0 ws0">modulation. </div><div class="t m0 x1 h5 yf ff3 fs2 fc0 sc1 ls0 ws0">&#19979;&#36733;</div><div class="t m0 x1 h4 y10 ff3 fs1 fc0 sc1 ls0 ws0">&#25991;&#20214;&#21517;<span class="ff1 sc0">: <span class="ff2 fc1">am_modulation.vi</span></span></div><div class="t m0 x1 h4 y11 ff3 fs1 fc0 sc1 ls0 ws0">&#35201;&#27714;<span class="ff1 sc0">: <span class="ff2 fc1">View</span></span></div><div class="t m0 x1 h7 y12 ff1 fs2 fc0 sc0 ls0 ws0">Background:</div><div class="t m0 x1 h6 y13 ff2 fs1 fc0 sc0 ls0 ws0">Amplitude Modulation (AM) is an analog modulation scheme where the amplitude (A) of</div><div class="t m0 x1 h6 y14 ff2 fs1 fc0 sc0 ls0 ws0">a fixed-frequency carrier signal is continuously modified to represent data<span class="_ _2"></span> in a message.' </div><div class="t m0 x1 h6 y15 ff2 fs1 fc0 sc0 ls0 ws0">The carrier signal is generally a high frequency sine wave used to &#8220;carry&#8221; the<span class="_ _2"></span> information</div><div class="t m0 x1 h6 y16 ff2 fs1 fc0 sc0 ls0 ws0">on the <span class="ff4">envelope</span> of the message.' The result is a double-sideband s<span class="_ _2"></span>ignal, centered on the </div><div class="t m0 x1 h6 y17 ff2 fs1 fc0 sc0 ls0 ws0">carrier frequency, with twice the bandwidth of the original signal.</div></div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div> </body> </html>