Understanding Oscilloscopes - Bandwidth

This video provides a technical introduction to oscilloscope bandwidth, including how bandwidth is specified, why bandwidth is important, and how to determine the bandwidth required for a given measurement application.
Learn more about Rohde & Schwarz Oscilloscopes: rsna.us/6052bjHwr
Timeline:
00:00 Introduction
00:18 About amplitude accuracy
01:13 Defining “bandwidth”
01:57 Consequences of insufficient bandwidth
02:35 Example: bandwidth and waveform shape
03:05 Example: bandwidth and rise time measurements
03:52 Selecting bandwidth for “analog” signals
04:55 Selecting bandwidth for “digital” signals
06:18 Bandwidth and frequency response
07:14 Gaussian frequency response
07:52 Flat (brick wall) frequency response
08:51 Passband flatness
09:34 Using rise time to determine required bandwidth
10:20 Calculating bandwidth from rise time
10:57 Using FFT to determine required bandwidth
12:02 System bandwidth
12:47 About probe bandwidth
13:34 Intentionally reducing bandwidth
14:26 Summary

[@kumara5288]

Nice explanation about Bandwidth. Thank you so much!

[@pauldenisowski]

Really appreciate the comment - thanks!

[@krish2nasa]

Excellent explanation as always. Thank you very much.

[@pauldenisowski]

Thanks for the feeback!

[@shalom-shlomi-zigdon6465]

GREAT presentation, excellent speaker, Thanks

[@pauldenisowski]

Thank you!

[@gonzaloroca5143]

Very useful information.

[@pauldenisowski]

Thanks!

[@sinojha1]

Great presentation as always, thank you!

[@pauldenisowski]

Thank you!

[@genericdynamics6618]

This is great content

[@pauldenisowski]

Thanks! There's more oscilloscope-related content coming soon!

[@user-nn1is7cc7e]

Hi, the flat response in the graphs on most pages don't correspond with the BW indication...just on page 12 it is shown right. Otherwise really good...thanks!

[@pauldenisowski]

Yes - on slide 11 the BW line is in the wrong place (should be to the right) and on slide 9 it's correct for Gaussian but should have moved to the right for Flat. All the other slides are correct. Thanks for letting me know!

[@arash4232]

Hi,
Thank you, that was excellent.
Is the 10x on the probe related to this topic as well? How does it contribute?
Regards.

[@pauldenisowski]

Thank you! The bandwidth of a probe is a function of several things, but the attenuation (10x) is not a significant contributor to probe bandwidth in most cases.

[@arash4232]

@@pauldenisowski thank you.

[@zokalyx]

Maybe I'm misunderstanding the comment, but doesn't a 10x probe increase probe bandwidth?@@pauldenisowski

[@pauldenisowski]

@@zokalyx 10x probes generally have wider bandwidths than 1X probes because the capacitance in the probe tip of a 10x probe helps to cancel out the inherent capacitance of the scope input - it's this capacitance, not the attenuation _per se_ ,that leads to wider bandwidth. Hope that makes sense!

[@zokalyx]

Thanks for the clarification! Totally clear now.@@pauldenisowski

[@lillyzegarra8025]

Why are you saying that frequency attenuated by 3 dB is (~30%)? WTF!

[@pauldenisowski]

If you listen to the spoken text (or turn on subtitles), I say "The bandwidth of an oscilloscope is defined as the frequency at which the measured amplitude of a sinusoidal input signal is decreased or attenuated by 3 dB" Since oscilloscopes measure voltage, a 3dB reduction is approximately 70% of the original amplitude (sqrt(2)/2). You're absolutely right that it would make no sense to talk about frequency being decreased by 3 dB :) But I can see where the bullet point might be confusing by itself, so thanks for letting me know!