PNA-X相位参考校准关于LO而不是RF的变化

如果您在功率扫描模式下设置SMC通道，这实际上是一个足够简单的测量。
在功率扫描模式下，所有3个频率范围（输入，LO和输出）都设置为固定，在电源选项卡和混音器电源选项卡中，您可以设置输入功率和LO功率的启动/停止值。
在您的情况下，您需要将输入电源启动/停止值设置为相同的值，并在调音台电源选项卡中，将LO电源启动/停止值设置为您希望看到更改的范围
处于IF（输出）的阶段。
在Sweep选项卡中，您还需要启用相位，然后决定您想要哪个LO功率作为相位测量的参考点（参考点将设置为0度相位）。
如果您感兴趣的是输出相位随LO功率的变化，您甚至不必校准此测量，只要我们确保所有LO功率电平，PNA-X接收器不是
在压缩。
我对其中一个临时转换器进行了快速测量，您可以在下面看到结果。
在我的情况下，我将参考相位设置为扫描的第一个点（最小LO功率），并将LO功率从-10 dBm扫描到+10 dBm。
正如您所看到的，输入相位不会发生变化（正如人们所预料的那样），但输出相位和SC21相位显然会随LO功率水平而变化。
！HTTPS：//dl.dropboxusercontent.com/u/87949221/Forum/ThreadID_38245/SMCPhaseVsLOPwr.png！



     以下为原文

  this is actually a simple enough measurement to make if you setup your SMC channel in power sweep mode.  In the power sweep mode all 3 frequency ranges (input, LO, and output) are set to fixed and in the power tab and mixer power tab, you can set start/stop values for input power and LO power.  in your case, you'll want to set the input power start/stop value to the same value, and in the mixer power tab, set the LO power start/stop values to the range over which you'll want to see the change in phase of the IF (output).  In the Sweep tab, you'll also need to enable phase and then decide which LO power you'll want as the reference point for the phase measurement (the reference point will be set to 0 degrees phase).  if all you are interested in is the change in the output phase as a function of the LO power, you don't even have to calibrate this measurement as long as we ensure that all the LO power levels, the PNA-X receivers are not in compression.  I did a quick measurement on one of my makeshift converters, and you can see the result below.  in my case, I set the reference phase to be the first point of the sweep (minimum LO power) and I swept the LO power from -10 dBm to +10 dBm.  as you can see, the input phase does not change (as one would expect), but the output phase and by extension the SC21 phase clearly do change as a function of the LO power level.

!https://dl.dropboxusercontent.com/u/87949221/Forum/ThreadID_38245/SMCPhaseVsLOPwr.png!

嗨daras，谢谢你的回复。
需要明确的是，在PNA-X上，它是由于进入转换器的所有输入（即RF和LO输入）而计算输出相位。
而不是严格地成为RF与IF的关系？
或者RF与IF关系是否仅适用于您无法访问LO的嵌入式LO情况？
谢谢，rok



     以下为原文

  Hi daras,

Thanks for the reply. Just to be clear, on the PNA-X, is it computing the output phase due to all the inputs into the converter (i.e. RF and LO inputs). rather than strictly being an RF vs IF relationship? Or would the RF vs IF relationship only apply in an embedded LO situation where you don't have access to the LO? 

Thanks,
rok

因为SMC + Phase的独特能力是能够独立测量每个接收器的相位变化（它不是一个比率），我们只是观察输出接收器中相位相对于刺激变化的变化。
由于LO信号的变化导致输入信号的变化导致输出相位的变化，我们无法区分输出相位的变化。
但是，因为在您的配置中，您将输入信号保持在固定的频率和功率，然后您可以安全地假设输出相位的变化只是LO功率变化的函数。
为了一个有趣的实验，你可以设置一个功率扫描案例，其中输入功率和LO功率扫描，如果你这样做，你将无法分辨由于各个组件的输出相位变化多少
输入或LO变化。



     以下为原文

  becuase the unique capability of SMC+Phase is the ability to measure the phase change in each receiver independently (it is not a ratio), we simply observe the change in phase in the output receiver over the change in stimulus.  we can't distinguish the change in the output phase as the result of change in the input signal from change in the output phase as the result of a change in the LO signal.  however, because in your configuration you are keeping the input signal at a fixed frequency and power, then you can safely assume that the change in the output phase is just a function of the change in the LO power.  

for a fun experiment, you could setup a power sweep case, where both the input power and the LO power sweep, and if you did that, you wouldn't be able to tell how much the output phase changed due to the individual components of input or LO change.

因为SMC + Phase的独特能力是能够独立测量每个接收器的相位变化（它不是比率），我们只需观察输出接收器中相位随激励变化的变化。
由于LO信号的变化导致输入信号的变化导致输出相位的变化，我们无法区分输出相位的变化。
但是，因为在您的配置中，您将输入信号保持在固定的频率和功率，然后您可以安全地假设输出相位的变化只是LO功率变化的函数。
为了一个有趣的实验，你可以设置一个功率扫描案例，其中输入功率和LO功率扫描，如果你这样做，你将无法分辨由于各个组件的输出相位变化多少
输入或LO变化。



     以下为原文

  because the unique capability of SMC+Phase is the ability to measure the phase change in each receiver independently (it is not a ratio), we simply observe the change in phase in the output receiver over the change in stimulus.  we can't distinguish the change in the output phase as the result of change in the input signal from change in the output phase as the result of a change in the LO signal.  however, because in your configuration you are keeping the input signal at a fixed frequency and power, then you can safely assume that the change in the output phase is just a function of the change in the LO power.  

for a fun experiment, you could setup a power sweep case, where both the input power and the LO power sweep, and if you did that, you wouldn't be able to tell how much the output phase changed due to the individual components of input or LO change.