I read in many forums that one can use a probe with a higher bandwidth than oscilloscope's bandwidth.
If it is right why it is not a problem? What is the theoretical explanation?
Electronic – Why would a 150 MHz probe work fine for a 100 MHz oscilloscope
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You see the horizontal arrow on the right vertical edge of the scope picture - it is quite close to the bottom edge of the waveform - it's called the trigger position and you can move it up and down from the trigger menu - try repositioning it and see what happens: -
I suspect on your scope there are two methods of calculating the frequency - one is based on the trigger threshold and the other is based on some other mechanism.
The main difference is that the BNC cable will look like a 1 MΩ (or 50 Ω, depending on how you set the scope) load to your circuit, rather than the higher impedance of the scope probe. This shouldn't make much difference at all as long as the INA193 has a low output impedance.
As long as the cable is short with respect to the wavelength of the highest frequency of interest, you won't need to think about transmission-line effects.
Also, you won't have the 10:1 attenuation of the probe, so adjust the vertical scale appropriately.
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Best Answer
That is right. Not a problem in doing that. Think of it as a filter between your oscilloscope and the point you are probing.
The bandwidth of the oscilloscope will determine the overall bandwidth of your "measuring system", since it is the most restrictive one.
For instance, if you are using a 150MHz probe with a 100MHz Oscilloscope, then the probe will attenuate the signals over 150MHz, and that input (with a 150MHz bandwidth) will enter your oscilloscope, which will then attenuate the signals over 100MHz. So your probe will pass the signals between 100MHz and 150MHz, but they will be filtered out by the oscilloscope input circuitry. In the end, you will have filtered the signals over 100MHz anyway, so no big diference with using a 100MHz probe.
In the other hand, if you use a probe with lower bandwidth, then it will determine the bandwidth of your input filter, and you will have less bandwidth in your input filter.