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.

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.

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.

嗨再次，我从你的图中看到你能够获得输入功率相位测量。
有没有办法在LO端口4侧获得类似的测量？
在那些选择中我找不到任何条目。
谢谢，rok



     以下为原文

  Hi again,

I saw from your plots that you were able to get the input power phase measurement. Is there any way to get a similar measurement for the LO port 4 side as well? I couldn't find any entry for that amongst the choices for that.

Thanks,
rok

嗨Rok，你所看到的是测量输出（IF）相位的变化，作为扫描LO功率的函数。
如果你看一下IPwr轨迹（mag和相位图中的紫色轨迹），你会注意到输入功率保持恒定-15 dBm的功率和扫描时的0度相位变化。
当您将SMC通道扫描类型更改为功率扫描时，您可以扫描输入功率或扫描LO功率或两者（虽然这不是很有用）。
我们在SMC中不能做的是直接测量LO信号的相位。
为此，您需要使用我们的非线性矢量网络分析（NVNA）应用程序。
通过该应用，我们可以测量混频器所有端口的相位。



     以下为原文

  Hi Rok,

What you are looking at is a measurement of the change of phase at the output (IF) as a function of sweeping the LO power. If you look at the IPwr trace (The purple trace in both mag and phase plots), you'll notice that the input power is kept to a constant -15 dBm power and 0 degrees phase change over the sweep.  When you change the SMC channel sweep type to power sweep, you can either sweep the input power or sweep the LO power or both (although that is not very useful).

What we cannot do in SMC is to measure the phase of the LO signal directly.  to do that you need to use our Nonlinear Vector Network Analysis (NVNA) application.  With that application, we can measure phase at all ports of a mixer.

嗨乔尔博士，谢谢你的回复。
我们尝试了你描述的方法，似乎我们观察到LO功率扫描部分的1度变化。
我正在与之合作的工程师想问你以下问题：'对于固定频率和固定RF，这是一个正确的陈述，SC21相位测量与LO驱动是DUT相位变化仅受LO功率驱动电平和
不是通过LO源相位变化（跨越不同的LO驱动功率）？
“谢谢，rok



     以下为原文

  Hi Dr Joel,

Thanks for the reply. We tried the method you described and it seems that we are observing about 1 degree of variation on the LO power sweep portion.  The engineer I am working with wanted to ask you the following question:

'Is it a correct statement then, for  fixed frequency, and fixed RF, the SC21 phase measurement vs LO drive is the DUT phase change affected only by LO power drive level and not by LO source phase change (across different LO drive powers)? '

Thanks,
rok

> {quote：title = rok写道：} {quote}>'这是一个正确的陈述，对于固定频率和固定RF，SC21相位测量与LO驱动是DUT相位变化仅受LO功率驱动电平和
不是通过LO源相位变化（跨越不同的LO驱动功率）？
'BZZT！
不，对不起，错误的答案，但感谢您玩“猜猜PNA-X是如何工作的！”
SC21测量非常简单。
它是在B接收器上测量的相位除以在R1接收器上测量的相位。
混频器输出相位是输入相位和LO相位以及混频器相移的乘积。
因此，如果LO随功率改变相位，输出信号也会相移，B接收器测量相移，SC21显示相移。
在前面的文章中，我展示了我书中的一个数字，它展示了如何测量LO的相位并从SC21中减去它（使用等式编辑器，它是（SC21 * mag（R3）/ conj（R3））编辑：
并且，为了使事情变得更复杂，LO相移可以具有正或负效果，这取决于RF是大于还是小于LO .RF的正常条件大于LO意味着LO相移提供RF相位
向下移，所以你联合LO测量（在我的情况下是在R3接收器上执行）。编辑：Dr_joel于2014年7月16日下午1:40



     以下为原文

  > {quote:title=rok wrote:}{quote}
> 'Is it a correct statement then, for  fixed frequency, and fixed RF, the SC21 phase measurement vs LO drive is the DUT phase change affected only by LO power drive level and not by LO source phase change (across different LO drive powers)? '

BZZT! No, sorry, wrong answer, but thanks for playing "guess how the PNA-X works!"

The SC21 measurment is really simple.  It is the phase measured on the B receiver divided by the phase measured on the R1 receiver.  

The mixer output phase is the product of the phase at the input, and the phase of the LO, and the phase shift of the mixer.  So if the LO changes phase with power, the output signal also shifts phase, the B receiver measures a phase shift and the SC21 displays a phase shift.

In the earlier post, I show a figure from my book that demonstates how to measure the phase of the LO and subtract it from the SC21 (using equiation editor, it is (SC21*mag(R3)/conj(R3))

edit: and, to make things more complicated, the LO phase shift can have either a positive or negative effect depending upon if the RF is greater or less than the LO. The normal condition of RF greater than the LO means LO phase shift up gives RF phase shift down, so you conj the LO measurement (which in my case is performed on the R3 receiver).

Edited by: Dr_joel on Jul 16, 2014 1:40 PM