PNA-X N5242AS接收器压缩测试失败

您好，显然我的帖子被截断了。
我从莫斯科是德科技服务中心收到N5242AS系列MY52071210的校准报告。
建议更换混合器砖26.5 Ghz Assy（无铅） - 5087-7829测试结果对我来说很奇怪 - 测量参数在20 GHz后一步变化非常快。
可能是PNA-X和校准设备之间的同步问题还是软件bug而不是PNA-X硬件问题？
如果混合器砖失效 - 可能是什么原因？
此致，Oleg Tokmakov



     以下为原文

  Hello,
Apparently my post was truncated.
I receive calibration report of N5242AS Serial MY52071210 from Moscow Keysight service center. Recommendation was to replace Mixer brick 26.5 Ghz Assy (Pb Free) - 5087-7829
Test results looks strange for me - measured parameter changes very rapidly after 20 GHz in one step. Could it be synchronization problem between PNA-X and calibration equipment or software bug rather the PNA-X hardware problem?
If it Mixer brick failure - what could be reason for that?
Regards,
Oleg Tokmakov

附件

• N5242AS Receiver Compression.pdf61.4 KB
  

这是非常奇怪的行为。
接收器在那个频率上没有什么变化，但在该区域有一个源频段。
还有IF增益放大器可以在更高频率下获得更多增益。
如果它们变坏了（从来没有听说过这种情况，但是我们在PNA上的故障很少，那么我们所做的一些事情往往很奇怪），那么它可能会导致这样的事情。
我会将此转发给我们的服务人员，看看他们是否有更好的主意。
我想知道操作检查结果是什么样的。
通常情况下，只需通过直通，衰减器和电源扫描即可在盒子上手动检查。



     以下为原文

  This is very odd  behavior.  There's nothing really that changes much in the receiver at that frequency, but there is a source band in that region.  There are also IF gain amplifiers that step in more gain at higher frequencies.  If they went bad (never heard of such a case, but then we have so few failures on PNA that the few we do have tend to be odd), then it might cause something like this. I will forward this to our service guys and see if they have a better idea.

I wonder what the op-check results looked like. Normally this can be checked manually on the box with just a thru, and attenuator, and a power sweep.

谢谢你的回答，Dr_Joel。
PNA仍在莫斯科是德科技服务中心。
我应该让他们进行操作员检查吗？



     以下为原文

  Thank you for your answer, Dr_Joel. 
PNA is still in Moscow Keysight service center. Should I ask them to run Operator's Check?

它不会伤害。
通常情况下，如果Rx压缩失败，则表明接收器已经以某种方式受到损害，但通常故障模式在所有频率上都会降级，并且通常只是超出规范而失败（有时过载可能会造成轻微损坏，对于
例）。
但是这种失败在22.2 GHz之间是完美的，然后非常糟糕，不遵循典型的模式。
我确定故障排除指南确实建议在压缩失败时更换接收器，但我很难看到坏接收器如何导致这种效果。
它应该在所有频率上都很糟糕。
我的猜测，只是猜测，它可能是数字转换器卡的参考通道中的错误IF增益阶段。
IF增益随频率的变化而变化，以补偿耦合器和混频器的转换损耗下降，并在更高的频率下获得更高的增益。
但即使这有点奇​​怪，因为它不会同样影响两个端口。
这个让我有点难过。
显示接收器响应与频率的运算测试可能提供一个很好的线索。
如果是我，我还会添加功率计测量并检查频率上的源功率。



     以下为原文

  It couldn't hurt.  Normally, if Rx Compression fails it is a sign that the receivers have been compromised in some way, but usually the failure mode is degradation across all frequencies, and usually it fails just out of spec (sometimes over-load can cause slight damage, for example).  But this failure where it is perfect up to 22.2 GHz, then very bad after doesn't follow the typical pattern. I'm sure the trouble shooting guide does recommend replacing the receivers when compression fails, but it's hard for me to see how a bad receiver could cause this effect.  It should be bad over all frequencies.

My guess, just a guess, is that it might be a bad IF gain stage in the reference channel of the digitizer card.   The IF gain is changed vs. freqeuncy to compensate for coupler and mixer conversion loss roll-off, and it goes to higher gain at higher freq.   But even this is a bit odd as it would not affect both ports identically.  This one has me a little stumped.  Op test showing the receiver response vs frequency might give a good clue.  If it were me, I'd also add a power meter measurement and check the source power across frequency.

我刚刚和我的同事交谈过，我认为他能够解决这个问题。
他的详细信息如下：Scott Stewart网络分析仪客户支持是德科技scott_stewart@keysight.com他建议您直接通过电子邮件与他联系。
由于某种原因，他现在无法登录论坛网站。



     以下为原文

  I just spoke with my colleage who will be able to sort this out I think.

His details are:
Scott Stewart
Network Analyzer Customer Support
Keysight Technologies
scott_stewart@keysight.com

He recommends you contact him directly by email. For some reason he cannot now log into the Forum site.

谢谢！



     以下为原文

  Thank you!