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王莹

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[问答]

PXA探测器怎么做10个计数的跟踪平均值

你好,这是关于PXA频谱分析仪模式下的探测器模式。
在探测器菜单下,我们有“平均”选项和“Log / RMS / V”。
在测量设置“平均类型”下选择该平均模式。
我们说,我选择了具有平均类型RMS的平均值检测器。
这里对存储桶中的采样点进行RMS平均,并显示该数据的日志(我处于日志显示模式)。
现在我正在做10个计数的跟踪平均值。
在此,每个跟踪点数据与下一个跟踪点数据(每个跟踪点的RMS值)进行平均,并显示平均值。
现在让我们说,我选择了“平均”探测器和“Log”平均模式。
此处对桶中每个样品的日志进行平均,并显示桶的平均值。通过跟踪平均,平均每个跟踪点并显示平均值。
在R& S分析仪中,我们可以选择RMS检测器,并且对于跟踪平均,存在log / lin / power选项。
我无法通过agilent等方式来解决这个问题。
感谢您的评论。

以上来自于谷歌翻译


     以下为原文

  Hello,

This is regarding detector modes in PXA Spectrum analyzer mode.
Under detector menu,  we have the "Average " option with "Log/RMS/V". This average mode is selected  under measurement set up "Average type".
Let us say, I have selected average detector with Average type RMS. Here the RMS averaging is done for the sample points in the bucket and the log of this data is displayed (I am in the log display mode). Now I am doing a trace average with 10  count. Here each trace point data is  averaged with the next trace point data (RMS value of each trace point) and the   average is displayed.
Now let us say, I have selected "Average" detector with "Log" average mode. Here Log of each sample in the bucket is averaged and the average is displayed for the bucket.With trace averaging,  each trace point is averaged  and the average is displayed.

In the R&S analyzers, we can select the  RMS detector and for trace  averaging, log/lin/power options are there. I am not able to releate this with way agilent is et up. Appreciate your comments.  

回帖(1)

李欢

2019-4-16 11:53:00
嗨 - 安捷伦和R& S称其探测器之间存在差异,可能还有自动耦合的方式。
安捷伦有一个平均值检测器,您可以选择平均记录功率类型(视频),平均功率平均值(RMS)或电压平均值。
R& S有一个RMS检测器,你提到它们有跟踪平均选择,如Log等。在PXA上,如果选择平均检测器,我们会自动耦合到RMS检测器类型。
这样做是因为这种组合提供了准确的信号幅度*和*噪声测量。
我们正在采用“平均值的对数”如果您遇到CW信号非常接近本底噪声的情况,并且您想要将信号“拉”出噪声,那么您可以很好地测量
信号,您可以选择平均值检测器和平均类型日志“日志的平均值”,这种组合会导致噪声报告不足(本底噪声会降低)。
您可以进行准确的CW信号测量,但不能进行准确的噪声测量。
有些人可能想要这样做,但他们需要了解风险是什么,并且“平均值的对数”不等于“日志的平均值”。
显然,如果您感兴趣的信号是类似噪声的通信信号,则您不希望选择平均值检测器和平均类型日志。
问候 -

以上来自于谷歌翻译


     以下为原文

  Hi -

There are differences between what Agilent and R&S call their detectors, and probably how the automatic coupling is done. 

Agilent has an Average detector, and you can chose the Average Types of Log power (video), Pwr Average (RMS) or Voltage avg. 
R&S has an RMS detector, and you mentioned they have trace averaging selections such as Log, etc.  

On the PXA, if you chose the Average Detector, we automatically couple to the RMS detector type. This is done because this combination provides accurate signal amplitude *and* noise measurements. We are taking the “log of the averages”

If you had a situation where the a CW signal was very close to the noise floor, and you wanted to “pull” the signal out of the noise so you could make a good measurement of the signal, you could chose Average detector and Average Type Log “the average of the Log”, and this combination would cause the noise to be under reported (the noise floor would decrease). You could make an accurate CW signal measurement but not an accurate noise measurement. Some people may want to do this, but they need to understand what the risk is and that the “log of the averages” is not equal to the “average of the Log”.  Obviously if your signal of interest is a noise-like comms signal, you would not want to select Average detector and Average Type Log.

Regards -
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