obsidian-notes/超短波/宽带接收机/混频器杂散.md

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2024-04-15 03:19:57 +00:00
---
title: 混频器杂散
updated: 2022-01-08 13:54:59Z
created: 2022-01-08 13:18:07Z
---
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<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-family:'Tahoma'; font-size:10pt;"><br /></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">混频器杂散主要是m*RF ± n*LO</span></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">以HMC557为例其杂散典型抑制如下图</span></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><img src="data:image/png;base64,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
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">其中,</span></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;"></span><span style=" font-family:'Tahoma'; font-size:10pt; font-weight:600;">1*RF ± n*LO</span><span style=" font-family:'Tahoma'; font-size:10pt;">需要着重关注,因为</span></p>
<ol style="margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;"><li style=" font-family:'Tahoma'; font-size:10pt;" style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">混频器自身对这些杂散抑制能力有限</li>
<li style=" font-family:'Tahoma'; font-size:10pt;" style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">RF的谐波一般在预选带外自身信号幅度也低LO却无法有效滤波且幅度高</li></ol>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">另外一个需要关注的是</span><span style=" font-family:'Tahoma'; font-size:10pt; font-weight:600;">2*RF ± 2*LO</span><span style=" font-family:'Tahoma'; font-size:10pt;">,因为</span></p>
<ol style="margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;"><li style=" font-family:'Tahoma'; font-size:10pt;" style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">混频器自身对这些交调抑制能力有限</li>
<li style=" font-family:'Tahoma'; font-size:10pt;" style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">此时引起杂散的RF可能就在预选带内</li></ol>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">m+n&gt;4的高次情况一般不着重考虑毕竟幅度很低</span></p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-family:'Tahoma'; font-size:10pt;"><br /></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">分析杂散时预选滤波器分段内</span></p>
<ol style="margin-top: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; -qt-list-indent: 1;"><li style=" font-family:'Tahoma'; font-size:10pt;" style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">总杂散数量尽量少</li>
<li style=" font-family:'Tahoma'; font-size:10pt;" style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">着重分析杂散中以上提到的杂散种类</li>
<li style=" font-family:'Tahoma'; font-size:10pt;" style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><br /></li>
<li style=" font-family:'Tahoma'; font-size:10pt;" style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><br /></li></ol>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;"></span><a href="nyf://entry?dbfile=&amp;itemid=54&amp;itemtext=RSA306B"><span style=" font-family:'Tahoma'; font-size:10pt; text-decoration: underline; color:#0000ff;">RSA306B</span></a><span style=" font-family:'Tahoma'; font-size:10pt;">的指标测试手册中获取信息如下:</span></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">杂散主要考虑由于RF与本振的多次谐波混频所产生的信号落入IF带内故RF=|n*LO</span><span style=" font-family:'Tahoma'; font-size:10pt; font-weight:600;">±</span><span style=" font-family:'Tahoma'; font-size:10pt;">IF|</span></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><span style=" font-family:'Tahoma'; font-size:10pt;">如果RF预选跨过倍频程还需要考虑</span><span style=" font-family:'Tahoma'; font-size:10pt; font-weight:600;">2*RF ± 2*LO</span><span style=" font-family:'Tahoma'; font-size:10pt;">是否落入IF带内</span></p></body></html>