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原厂入驻New

射频知识

2008-6-10 13:25:02  4041
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<p><span>射频知识</span><br/></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">天线前后比:指最大正向增益与最大反向增益之比,用分贝表示。 <span lang="EN-US"><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">单工:亦称单频单工制,即收发使用同一频率,由于接收和发送使用同一个频率,所以收发不能同时进行,称为单工。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">双工:亦称异频双工制,即收发使用两个不同频率,任何一方在发话的同时都能收到对方的讲话。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">单工、双工都属于移动通信的工作方式。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">放大器:(<span lang="EN-US">amplIFier</span>)用以实现信号放大电路。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">滤波器:<span lang="EN-US">(filter)</span>通过有用频率信号抑制无用频率信号的部件或设备<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">衰减器:<span lang="EN-US">(attenuator) </span>在相当宽的频段范围内一种相移为零、其衰减和特性阻抗均为与频率无关的常数的、由电阻元件组成的四端网络,其主要用途是调整电路中信号大小、改善阻抗匹配。 <span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">功分器:进行功率分配的器件。有二、三、四<span lang="EN-US">….</span>功分器;接头类型分<span lang="EN-US">N</span>头(<span lang="EN-US">50Ω</span>)、<span lang="EN-US">SMA</span>头(<span lang="EN-US">50Ω</span>)、和<span lang="EN-US">F</span>头(<span lang="EN-US">75Ω</span>)三种,我们公司常用的是<span lang="EN-US">N</span>头和<span lang="EN-US">SMA</span>头。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">合器:从主干通道中提取出部分信号的器件。按耦合度大小分为<span lang="EN-US">5</span>、<span lang="EN-US">10</span>、<span lang="EN-US">15</span>、<span lang="EN-US">20…. dB</span>不同规格;从基站提取信号可用大功率耦合器(<span lang="EN-US">300W</span>),其耦合度可从<span lang="EN-US">30~65dB</span>中选用;耦合器的接头多采用<span lang="EN-US">N</span>头。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">负 载:终端在某一电路(如放大器)或电器输出端口,接收电功率的元<span lang="EN-US">/</span>器件、部件或装置统称为负载。对负载最基本的要求是阻抗匹配和所能承受的功率。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">环形器:使信号单方向传输的器件<span lang="EN-US">.<o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">转接头:把不同类型的传输线连接在一起的装置。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">馈 线:是传输高频电流的传输线。<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">天 线:<span lang="EN-US">(antenna)</span>是将高频电流或波导形式的能量变换成电磁波并向规定方向发射出去或把来自一定方向的电磁波还原为高频电流<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">光纤知识<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">光功率:衡量光信号的大小,可用光功率计直接测试,常用<span lang="EN-US">dBm</span>表示<span lang="EN-US"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal" style="MARGIN: 0cm="0cm"  0cm="0cm"  0pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt" align="left"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">光端机:主要由光发送机和光接收机组成,功能是将要传送的电信号及时、准确的变成光信号并输入进光纤中进行传播(光发送机);在接收端再把光信号及时、准确的恢复再现成原来的电信号(光接收机)。由于通信是双向的,所以光端机同时完成电<span lang="EN-US">/</span>光(<span lang="EN-US">E/O</span>)和光<span lang="EN-US">/</span>电(<span lang="EN-US">O/E</span>)转换。<span lang="EN-US"><o:p></o:p></span></span></p>
0
2008-6-10 13:25:02   评论 分享淘帖
8 个讨论
<p>谢谢</p>
2008-7-19 22:37:38 评论

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kankank
2009-12-5 12:10:37 评论

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<p>看了下,疑问有两个:<br/>第一:你说的“<span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">天线前后比</span>”与我们常说的驻波比有何区别?<br/>第二:你说的“<span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-fareast-font-family: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体; mso-ascii-theme-font: minor-fareast; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-fareast">环形器</span>”是不是我们常说的“隔离器”?正向导通,反向有20DB的衰减……</p>
<p>&nbsp;</p>
<p>&nbsp;请问可以帮我解答下么?<br/>谢谢</p>
[此贴子已经被作者于2009-12-6 22:46:45编辑过]
2009-12-6 22:46:21 评论

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这个可以额。。。
2009-12-11 15:33:34 评论

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路过看见,支持一下!顶!顶!顶!
2016-9-7 07:20:41 评论

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ssssssssssssssssss
2016-10-28 19:29:49 评论

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hhhhhhhhhhhhhhhhhhhhh
2016-10-28 19:30:07 评论

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谢谢
2016-10-28 19:30:59 评论

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