天线与 RF模块之间的同轴连接线阻抗问题

yellowtoot · 发表于 2005-12-21 17:02:00

在调试天线时,通常用一根同轴线连接到矢网上

这根同轴线是算在较准里的.

在此条件下调好一个天线后, 接上另一根同轴电缆到RF模块后发现效果不好,

用矢网测这根同轴+天线, 结果发现频率发生很大的偏移, 有时甚至连谐振频率点都没有啦(S11一条水平线)

不知大家有没有碰到过这种现象呀?

另外,偶单测这根电缆,即将其串联在矢网的两个端口间,发现带基本在圆心位置.
[em13]

Hsin · 发表于 2005-12-21 17:05:00

change coaxial cable, do calibration again[br]+3 RD币

yellowtoot · 发表于 2005-12-22 08:42:00

To change which one ?One is the attatchment of the VNA, another is my feed line.

Eternallove · 发表于 2005-12-22 16:23:00

只用了这两根制具线吗?有可能是第二根同轴线的芯线和外面铜管之间有偶尔短路的地方.[br]+3 RD币

yellowtoot · 发表于 2005-12-22 17:54:00

<DIV class=quote>以下是引用Eternallove在2005-12-22 16:23:20的发言：

只用了这两根制具线吗?
有可能是第二根同轴线的芯线和外面铜管之间有偶尔短路的地方.</DIV>

你好,你说得太专业啦,"制具线"是什么东东啊? 是不是钢性同轴电缆呀? 外边包的是铜管的那种.

我用的不是外包铜管的钢性硬同轴电缆, 而是MURARA生产的直径1mm的软同轴线,两头带射频连接头的.

天线与矢网间,串联这根同轴与不串联它时,驻波变化非常大,频率都漂得看不到谐振点啦.

惨!

Hsin · 发表于 2005-12-22 21:13:00

I mean that:if you want to test a device and use a cable to connect to the network analyzer, you should do calibration with the cable before connect the device. If you switch to another cable, you should do calibration again. It is the device which you want to test. Not the cable, nor the cable & device together.[br]+5 RD币

gywang99 · 发表于 2005-12-23 01:46:00

To check the network analyzer scan range is wide enough? To make sure the cable connected to network analyzer isn't broken, or two cores of the two side connectors are not intermittent. You should see the resonate point if the cable is connected to the network analyzer well.

yellowtoot · 发表于 2005-12-23 08:56:00

<DIV class=quote>以下是引用Hsin在2005-12-22 21:13:01的发言：

I mean that:
if you want to test a device and use a cable to connect to the network analyzer, you should do calibration with the cable before connect the device. If you switch to another cable, you should do calibration again. It is the device which you want to test. Not the cable, nor the cable & device together.

+5 RD币</DIV>

I should not do calibrition again for the feed line is indeed needed in real usage.

So I realy want to test the whole device, that are both antenna and feed line.

yellowtoot · 发表于 2005-12-23 09:01:00

<DIV class=quote>以下是引用gywang99在2005-12-23 1:46:27的发言：

To check the network analyzer scan range is wide enough? 
To make sure the cable connected to network analyzer isn't broken, or two cores of the two side connectors are not intermittent. 
You should see the resonate point if the cable is connected to the network analyzer well.</DIV>

The max scan already.

I am sure that it is not broken,

But I am not sure if it is conected well.

And I think it should be conected well at some time, but no good test reults at all time.

[em04]

Hsin · 发表于 2005-12-23 14:41:00

<DIV class=quote>以下是引用yellowtoot在2005-12-23 8:56:19的发言：

I should not do calibrition again for the feed line is indeed needed in real usage.

So I realy want to test the whole device, that are both antenna and feed line.</DIV>

Then you should not include the cable when you do the first calibration.

yellowtoot · 发表于 2005-12-24 08:49:00

<DIV class=quote>以下是引用Hsin在2005-12-23 14:41:25的发言：

Then you should not include the cable when you do the first calibration.</DIV>

Yes, I just do like this.
[em04]

yellowtoot · 发表于 2005-12-24 08:50:00

现在,偶将这个球踢给天线厂家啦, 请他们高手帮我调调看[em08]

mwang · 发表于 2016-12-2 21:39:07

电缆是坏的
[em01]

frankwangbb · 发表于 2017-1-13 16:08:30

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[讨论] 天线 与 RF模块 之间的同轴连接线阻抗问题

[讨论] 天线与 RF模块之间的同轴连接线阻抗问题