What is oscilloscope bandwidth? Oscilloscope bandwidth settings
The oscilloscope bandwidth refers to inputting a signal with the same amplitude and changing frequency. When the oscilloscope reading is attenuated by 3dB compared with the true value, the frequency at this time is the bandwidth of the oscilloscope. In other words, the test value of the input signal at the oscilloscope bandwidth is the true value -3dB, and the bandwidth is not the highest frequency that the oscilloscope can display. Generally speaking, the bandwidth of the oscilloscope should be 3 to 5 times the highest frequency of the signal being measured.
Closely related to an oscilloscope's bandwidth specification is its rise time parameter. An oscilloscope with a Gaussian frequency response has a rise time of about 0.35/fBW based on the 10% to 90% standard. The rise time specification of an oscilloscope with the largest flat frequency response is generally in the 0.4/fBW range, which varies with the steepness of the frequency roll-off characteristic of the oscilloscope. If a 20% timing error is allowed when making rise and fall time parameter measurements, an oscilloscope with a bandwidth of 1 GHz will suffice for this digital measurement application. But if the timing accuracy is required to be within 3%, it is better to use an oscilloscope with a bandwidth of 2GHz.
How to adjust the bandwidth limit of the oscilloscope
In the channel button of the instrument, if you press the CH1 button, the menu that appears should have the option of bandwidth limit.
There is circuitry in most oscilloscopes that limits the bandwidth of the oscilloscope. After the limited bandwidth is turned on, the noise that appears from time to time in the displayed waveform can be reduced, and the displayed waveform will appear clearer. But please note that when eliminating noise, bandwidth limitation will also reduce or eliminate high-frequency signal components. Dingyang oscilloscope, after the bandwidth limit is turned on, it will effectively filter out noise signals above 20M
