Infiniium 90000A系列示波器中的抗混叠滤波器怎么配置

我不确定你要做什么，但是...... - 示波器中内置了抗锯齿，但它只能以最高的采样率工作。
如果以5GSa /秒采样，则没有抗锯齿。
在时域和频域，2GHz正弦波看起来很像3GHz正弦波。
- 同样，如果你动画80GSa捕获，这里将没有抗锯齿。
- 当示波器使用“带宽限制”模式时，它在采集后使用数字滤波器进行。
A / D仍然看到完整的BW信号。
- 即使看起来有效，也不要在“带宽限制”模式下使用降低的采样率 - 波特图不可用，但您可以创建自己的。
捕获非常快的边缘，越快越好。
创建一个函数来区分捕获（将边缘转换为脉冲）。
创建一个函数来对脉冲进行FFT。
示波器为Cal Out信号提供快速边沿。
使用最好的电缆和适配器。
为获得最佳效果，您应该使用另一个函数对FFT进行平均。
上面的一些是来自记忆。
我没有回到技术文档来验证一切。
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     以下为原文

  I'm not sure what you're trying to do, but...
- There is anti-aliasing built into the scope, but it only works at the highest sample rates. If you sample at 5GSa/sec, there is no anti-aliasing. A 2GHz sine wave will look a lot like a 3GHz sine wave, in both time and frequency domain.
- Similarly, if you decimate an 80GSa capture, here will be no anti-aliasing.
- When the scope is using "Bandwidth Limit" mode, it's doing that with a digital filter after acquisition. The A/D is still seeing full BW signals.
- Even though it appears to work, don't use reduced sample rates with "Bandwidth Limit" mode
- The Bode Plots are not available, but you can create your own. Capture a very fast edge, the faster the better. Create a function to differentiate that capture (that turns the edge into a pulse). Create a function to do an FFT of the pulse. The scope provides a fast edge on the Cal Out signal. Use the best cable and adapters you have. For best results, you should average the FFT with another function.

Some of the above is from memory. I have not gone back into the technical documents to verify everything.

Al

Disclaimer: For more reliable response, you should consider calling your local Keysight Technical Call Center. The Keysight Forums are monitored on an "as available" basis, and aren't necessarily the fastest way to get technical questions answered.

是的，我正在询问用于信号抽取的数字滤波器，从80GSa / s到5GSa / s。
你有这种数字滤波器的顺序和系数吗？
或者波德情节可能？
在回复的第3点，您解释了“带宽限制”功能是可选的。
但我似乎无法在“获取设置”对话框中禁用它。
在对话中，它是16GHz带宽或5GSa / s采样率，但不是两者同时。



     以下为原文

  Yes i am inquiring digital filter employed for signal decimation from 80GSa/s to 5GSa/s. Do you have the order and the coefficients of such digital filter? Or the Bode plot maybe?

And in point #3 of your reply, you explained as if the "bandwidth limit" function is optional. But I don't seem to be able to disable it in the "Acqusition setting" dialogue. In the dialogue, it is either 16GHz bandwidth or 5GSa/s sample rate, but not both at the same time.

我想我不清楚，或者我不明白你在寻找什么。
- 以5GS / s的速度运行时，没有抗混叠滤波器。
- 没有用于抽取的过滤器。
在5GSa / s时，使用每16个样本，其他样本被丢弃。
- 在更高的采样率下，我认为那些是40和80 GSa / s，采用抗锯齿，并且采集窗口中的BW限制选择将起作用。
在较低的采样率下，没有抗锯齿，并且采集窗口中的BW限制选择将产生不良结果，不应使用。
显示的BW - 如果BW限制设置为“自动”，并且您更改采样率，从80Gsa / s降至10GSa / s，BW将自动降压，变为采样率的约0.4倍。
如果你降低到5Gsa / s，然后降低，则BW保持在4GHz，即使这没有任何意义。
然后，你正在做的事情也没有任何意义。
- 如果将BW限制设置为“手动”，则示波器将不允许您将采样率设置为低于20 GSa / s。
- 如果您使用较低的采样率，则您（用户）有责任确保信号中没有高于奈奎斯特限制的频率内容，或者结果非常值得怀疑。
我有32GHz示波器和20GHz射频信号发生器。
我只是将采样率设置为5GSa / s，并在运行FFT时从1 GHz扫描到20 GHz的正弦波。
正如我所预料的那样，当我穿过各个奈奎斯特区域时，我看到了FFT扫描中的尖峰来回。
人



     以下为原文

  I guess I wasn't clear, or I don't understand what you're looking for.

- There is no anti-aliasing filter when running at 5GS/s.
- There is no filter that is used for the decimation. At 5GSa/s, every 16th sample is used, and the others are thrown away.
- At the higher sample rates, I think that those are 40 and 80 GSa/s, anti-aliasing is employed, AND the BW limit choice in the acquisition window will work. At lower sample rates, there is no anti-aliasing, and the BW limit choice in the acquisition window will give bad results, and should not be used. The displayed BW
- If the BW limit is set to "Automatic", and you change the sample rate, stepping down from 80Gsa/s to 10GSa/s, The BW will automatically step down, changing to approximately 0.4 times the sample rate. If you step down to 5Gsa/s, and lower, the BW stays at 4GHz, even though that doesn't make any sense. Then again, what you are doing doesn't make any sense, either.
- If you set the BW limit to "Manual", the scope will not allow you to set the Sample rate to any lower than 20 GSa/s.
- If you use the lower sampling rates, you, the user, are responsible for making sure that there is no frequency content in the signal above the Nyquist limit, or the results are highly questionable.

I have a 32GHz scope and a 20GHz RF signal generator. I just set the sampling rate to 5GSa/s and swept a sinewave from 1 GHz to 20GHz, while running an FFT. As I expected, I watched the the spike in the FFT sweep back and forth as I ran through the various Nyquist zones.

Al