[SOLVED] how oscilloscope passive probe 's bandwidth is specified?

[parachutes30]

x10 probe has 200M bandwidth. how it is calculated?

x1 probe has low bandwidth such as 6M. Why it's so low than x10 probe? I think x1 probe has no resistor in its body and it has no way to form a low pass filter with capcitor.

 

[dick_freebird]

Calculated? No, it's measured and then stated in the
product datasheet. Which it might do you good to find
the specific one, for, and look at. The -particular- 1X
probe may just be a lousy one. I wouldn't generalize the
BW to all, I've had 1X probes with no such limitation.

 

[andre_luis]

The datasheet of an oscilloscope probe shows a curve with the typical attenuation along the frequency spectrum; As said above, that response was not calculated by manufacturer, but measured.

 

[FvM]

x1 probe has low bandwidth such as 6M. Why it's so low than x10 probe? I think x1 probe has no resistor in its body and it has no way to form a low pass filter with capcitor.

Not quite true. Passive oscilloscope probes use resistive (lossy) coaxial cable to reduce reflections. A 100 or 200 MHz 10x probe has a rather complicated compensation network to setup a flat overall transfer characteristic. This option doesn't exist for a 1x probe, feasible 1x probe bandwidth is 20 or 25 MHz.

You can however use a 50 ohm coaxial cable with 50 series resistor at the signal source the to make a wide bandwidth x1 probe.

 

[parachutes30]

Do you mean manufacturer speicify the bandwidth of probe by the use of a 50 ohm impedance signal source and then measure it?

 

[FvM]

Do you mean manufacturer speicify the bandwidth of probe by the use of a 50 ohm impedance signal source and then measure it?

Maybe the do. But I was suggesting an alternative method to make a wide band x1 probe.