有线数字电视工程基本知识(一)...

 
<p style="TEXT-INDENT: -27pt; MARGIN-LEFT: 27pt; mso-list: l0="l0"  level1="level1"  lfo1; tab-stops: list="list"  27.0pt" class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 13.5pt; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: 宋体" lang="EN-US"><span style="mso-list: Ignore">一、</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">常用<a href="http://b2b.hc360.com/supplyself/129429799.html">有线电视器材</a></span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></span></p>
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">１、电缆</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br style="mso-special-character: line-break"/><br style="mso-special-character: line-break"/><o:p></o:p></span></p>
<table style="BORDER-BOTTOM: medium="medium"  none; BORDER-LEFT: medium="medium"  none; BORDER-COLLAPSE: collapse; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: medium="medium"  none; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-yfti-tbllook: 480; mso-padding-alt: 0cm="0cm"  5.4pt 0cm="0cm"  5.4pt; mso-border-insideh: .5pt solid="solid"  windowtext; mso-border-insidev: .5pt solid="solid"  windowtext" class="MsoTableGrid" border="1" cellspacing="0" cellpadding="0">
<tbody>
<tr style="mso-yfti-irow: 0; mso-yfti-firstrow: yes">
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 95.4pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext="windowtext"  1pt="1pt"  solid; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="127">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">型号：</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td>
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: medium="medium"  none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 207pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext="windowtext"  1pt="1pt"  solid; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-left-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="276">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">常用电缆</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;75-5&nbsp;75-7&nbsp;75-9&nbsp;75-12</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td></tr>
<tr style="mso-yfti-irow: 1">
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 95.4pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-top-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="127">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">发泡：</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td>
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: medium="medium"  none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 207pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-left-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-top-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="276">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">单护发泡、双护发泡</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">.</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td></tr>
<tr style="mso-yfti-irow: 2">
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 95.4pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-top-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="127">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">类型：</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td>
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: medium="medium"  none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 207pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-left-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-top-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="276">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">发泡电缆、耦芯电缆、进口电缆</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td></tr>
<tr style="mso-yfti-irow: 3; mso-yfti-lastrow: yes">
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 95.4pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-top-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="127">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">特点：</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td>
<td style="BORDER-BOTTOM: windowtext="windowtext"  1pt="1pt"  solid; BORDER-LEFT: medium="medium"  none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 207pt; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium="medium"  none; BORDER-RIGHT: windowtext="windowtext"  1pt="1pt"  solid; PADDING-TOP: 0cm; mso-border-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-left-alt: solid="solid"  windowtext="windowtext"  .5pt; mso-border-top-alt: solid="solid"  windowtext="windowtext"  .5pt" valign="top" width="276">
<p class="MsoNormal"><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">频率越高，损耗越多。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p></o:p></span></p></td></tr></tbody></table>
<p class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">２、分支分配器</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">⑴</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分支器</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分支器通常用于较高电平的馈电干线中</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">它能以较小的插入损耗从干线取出部分信号供给住宅楼或用户</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">有时也可用二分支干线提供信号电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">通过分支器的电视信号其中一小部分从分支端输出</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">大部分功率继续沿干线传输。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">BR</span></span><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">一分支符号：</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;IN&nbsp;OUT(</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">插入损耗</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">)</span></span><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><br/><span class="apple-style-span">A</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：插入损耗：是信号从干线输入端到干线输出端之间的传输损耗，即输入信号电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">(dB)</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">与输出信号电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">(dB)</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">之差</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">用</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">dB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">表示。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">B</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：分支损耗：是信号从干线输入端到分支输出端之间的损耗，即干线输入端电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">(dB)</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">与分支端输出电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">(dB)</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">之差</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">用</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">dB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">表示。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">C</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：分支损耗与插入损耗之间的关系是：分支损耗大，则插入损耗小；</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分支损耗小，则插入损耗大。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">例：</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;</span></span><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><br/><span class="apple-style-span">108</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">3dB&nbsp;208:&nbsp;3.5dB</span></span><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><br/><span class="apple-style-span">112:&nbsp;1dB&nbsp;212:&nbsp;2dB</span><br/><span class="apple-style-span">120:&nbsp;0.5dB&nbsp;220:&nbsp;1dB</span><br/><span class="apple-style-span">D:</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分支口与插入损耗之间的关系是：分支口越多</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">,</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">插入损耗越大。我们实际上设计中通常按照</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">2DB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">来计插入损耗。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">⑵</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分配器</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'"><a href="http://b2b.hc360.com/supplyself/129429799.html">分配器</a>是用来分配高频信号的部件，它的作用有两个：一是将一种信号功率平均分配给几路（通常是分为两路、三路、四路、六路）；二是可将两路、三路、四路和六路信号混合起来。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分配损耗：是指分配器输入端的输入电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">Ui(dB)</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">与输出电平</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">Uo(dB)</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">之差。</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;</span></span><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分支器和分配器的<a href="http://b2b.hc360.com/supplyself/129429799.html">根本区别在于</a>，分配器平均分配功率，而分支器是从电缆中取</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">出一小部分功率提供给用户，而大部分功率继续向后面传输。</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">&nbsp;</span></span><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">３、串接分支器（串接单元）</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">串接分支器是将分支器和用户终端合成为统一体，具有分支器和系统输出口的功能，所以叫串接分支器，有的又叫串接单元。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">４、用户盒</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">用户终端是</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">CATV</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">分配系统与用户电视机相连的部件。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">面板分为单输出孔和双输出孔（</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">TV</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">、</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">FM</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">），在双输出孔电路中要求</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">TV</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">和</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">FM</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">输出间有一定的隔离度，以防止相互干扰。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">为了安全而在两处电缆芯线之间接有高压电容器。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">５、放大器（高电平放大器、中电平放大器、低电平放大器）</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">A</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：高电平放大器用于天线放大器，用户放大器，增益大在</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">40dB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">以上，信噪比较差，输入低</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">60dB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">特点：低输入，高输出</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">B</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：中电平放大器用在支干线上，增益在</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">25-30dB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">，如</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">KA5134</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">，信噪比较好。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">C</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">：低电平放大器用在主干线上，增益在</span></span><span class="apple-style-span"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US">18-25dB</span></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">，信噪比最好。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">６、功分器</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'"><a href="http://b2b.hc360.com/supplyself/129429799.html">功率分配器</a>简称为功分器，它是把输入信号功率等分或不等分成几路功率输出的器件。在卫星电视接收中，利用功率分配器，就可使用一副天线、一个室外单元和几个接收机，同时收看卫星传送同频段的多套电视节目。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span><span class="apple-style-span"><span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 13.5pt; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">功分器目前有无源和有源两种。无源功分器通常是由纯微带电路组成，有源功分器是在无源功分器的基础上加入宽频带放大器组成的。</span></span><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><br/></span></p>
<p class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 9pt" lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 13.5pt" lang="EN-US"><span class="apple-style-span">本帖最终解释归属于帖主JDS、如有疑问与贴主联系QQ：97670824；Tel:13925269500） </p>
<p>&nbsp;<br/><ignore_js_op>更多咨信欢迎登陆网易博客：<font face="Verdana"><a href="http://jdssun.blog.163.com/">http://jdssun.blog.163.com/</a></font></p></span></span>

受教了

&nbsp;&nbsp; 学习了

学习了