全2端口校准后的端口切换怎么阻止

执行双端口校准时，固件会推断您要测量和校正任何和所有S参数，以了解源和负载匹配的影响。
校正要求固件知道所有原始的4个S参数，因此它必须测量全部4个（正向的S11和S21，从端口1输出，以及从端口2反向输出的S12和S22）。
因此，您将看到分析仪持续切换。
也许你可以说出为什么你不希望它不断切换？
通常，您无法停止正常操作。
有办法阻止它，但它们往往是特殊情况。



     以下为原文

  When you perform a 2 port calibration, the Firmware infers that you want to measure and correct any and all S-parameters for the effects of source and load match.  The correction requires the firmware to know all raw 4 S-parameters, and so it must measure all 4 (S11 and S21 in the forward direction, sourcing from port 1, and S12 and S22 in the reverse direction sourceing from port 2).  So you will see the analyzer switch continuously.

Perhaps you can tell why you don't want it switching continuously?  In general, you cannot stop it for normal operation.  There are ways to stop it, but they tend to be special cases.

嗨，Joel博士，是否通过RF开关完成端口切换？
我担心因磨损导致的连续切换。
机械式射频开关撕裂。
如果在使用完整的2端口校准时连续切换是正常的（RF开关没有磨损和撕裂），那么我应该没有进一步的问题，尽管我不喜欢在工作时看到方向标志来回切换
非常恼火。
我需要测试2端口隔离器的回波损耗/插入损耗/隔离。
因此，完整的2端口校准是完成这项工作的唯一方法。
但如果我必须了解磨损和
RF开关的撕裂然后我必须使用其他方式。
谢谢＆amp;
此致，Pairoj



     以下为原文

  Hi Dr. Joel,

Is port switching done by RF switch? I am concerned with continuous switching due to wear & tear of mechanical RF switch. If it is normal (no wear & tear for RF switch) to have continuous switching when using full 2 port calibration then I should have no further question though I don't like to see direction sign switching back and forth while working as it is quite irritating.

I need to test return loss/insertion loss/isolation of a 2 port isolator. So full 2 port calibration is the only way to do the job. But if I have to be aware of wear & tear of RF switch then I have to use other way.

Thanks & Regards,
Pairoj

自1989年以来，HP的所有VNA（当时的安捷伦和后来的Keysight）都使用了电子端***换机。
事实上，我为8753和8720设计了开关。在某些情况下，您可以将衰减器或其他机械开关设置为不同的端口或通道的不同设置，如果出现这种情况，固件始终将分析仪置于“测试设置保持”状态
模式，只扫描一个方向。
因此，实际上不可能将VNA置于连续切换机械开关的模式中。
由于没有磨损机制，因此电子开关的切换没有限制。
如果闪烁的灯光打扰你（我第一次听到这样的事情，但无论如何）我可以建议你在它们上面放一小块电工胶带，这样你就不会看到闪光或遮蔽胶带，如果你想要的话
仍然看到指标但没有那么明亮。



     以下为原文

  Since 1989, all VNA's from HP (then Agilent and then Keysight) have used electronic port switches.  In fact I designed the switch for the 8753 and the 8720.  

In some cases you can set attenuators or other mechnical switches to different settings for different ports or channels, and if that situation occurs the firmware always places the analyzer in "test set hold" mode and only sweeps in one direction.  So it is not really possible to put the VNA in a mode to continously switch mechanical switches.

There is no limit to the switching of the electronic switches as there is no wear-out mechanism.

If the flashing lights bother you (first time I've heard such a thing, but whatever) I could recommend you put a small piece of electrical tape over them so you don't see the flashing, or masking tape if you you want to still see the indicator but not have it so bright.

谢谢你的澄清！
由于没有磨损问题，我猜闪烁LED的烦恼现在要少得多！



     以下为原文

  Thanks for clarification! 

Since there is no wear out problem I guess the annoyance of flashing LEDs is now much less!

> {quote：title = aerocomm写道：} {quote}>嗨，>>执行全2端口校准后，为什么还有端口切换？
我怎么能阻止它？
这发生在8720D和我的新E5063A上。
>>感谢您的帮助。
>> Pairoj S.这个“问题”还有另一个恼人的方面，它需要比胶带更高的技术方法。
完成2端口校准后，如果您想测量单端口设备，则需要两倍的时间，因为8720D正在执行正向和反向扫描，尽管您只使用了一个。
截至6个月前，我被告知PNA也是如此，尽管有计划让用户选择不执行反向扫描。
Joel表示应该可以在我的8720D上停止此操作，但它需要下载校准系数，让VNA认为它已完成单端口校准，然后上传校准常数。
这听起来很多，所以我从来没有这样做过。
但是对于磨损，这不是问题。
我只是伸手去拿我的手，拿出一台Agilent 874B DC-18 GHz机械继电器。
对Keysight网站的快速检查表明，它的评级超过了100万次。
因此，如果具有机械继电器的VNA（8720D上的选件）确实允许*有限*的开关周期，那么恕我直言，它不会受到太大伤害。
如果你可以做100个循环，那么磨损继电器需要很长时间。
戴夫



     以下为原文

  > {quote:title=aerocomm wrote:}{quote}
> Hi,
> 
> After performing full 2 port calibration why is there port switching continuously? How could I stop it? This happens to 8720D and my new E5063A. 
> 
> Thanks for any help.
> 
> Pairoj S.

There is another annoying aspect to this "problem", which needs a slightly higher tech approach than the sticky tape. 

After you have done a 2-port calibration, if you then want to measure one-port devices, it takes twice as long, as the 8720D is performing both a forward and reverse sweep despite you are only using one. As of about 6 months ago I was advised this was the same on the PNA too, although there were plans to give the user the option to not perform the reverse sweep. 

Joel said it should be possible to stop this on my 8720D, but it required downloading the calibration coefficients, getting the VNA to think it had done a one-port calibration, then uploading the calibration constants. It sounded a lot of work, so I never done this. 

But for wear out, this is not an issue. 

I just stuck my hand in my draw and pulled out an Agilent 874B DC-18 GHz mechanical relay. A quick check of the Keysight website shows it is rated for greater than 1 million cycles. So IMHO it would not have hurt too much if the VNAs which have mechanical relays (an option on the 8720D), did allow a *limited* number of switching cycles. If you could do it for 100 cycles, it would take a very long time to wear out the relay. 

Dave

谢谢你的解释。



     以下为原文

  Thanks for more explanation.