Bandwidth is one vital index of oscilloscope. Bandwidth of analog oscilloscope is one certain value, however, bandwidth of digital oscilloscope has two kinds, analog bandwidth and digital real-time bandwidth. Digital oscilloscope to repeating the signal in a sequential sampling and random sampling technology can achieve the maximum bandwidth of the oscilloscope digital real-time bandwidth, real-time digital bandwidth and the highest frequency and digital waveform reconstruction technology related factor K = (digital real-time bandwidth digital highest rate/K), generally not directly given as an indicator. It can be seen from the definition of the two kinds of bandwidths that the analog bandwidths are only suitable for the measurement of repeated periodic signals, while the digital real-time bandwidths are suitable for the measurement of repeated signals and single signals at the same time.
The manufacturer claims the bandwidth of oscilloscope can achieve how many megabytes, it is analog bandwidth actually, digital real time bandwidth is below this value. For example, if the bandwidth of an oscilloscope is 500MHz, it actually means that its analog bandwidth is 500MHz, while the highest digital real-time bandwidth can only reach 400MHz, which is much lower than the analog bandwidth. Therefore, when measuring a single signal, it is necessary to refer to the digital real-time bandwidth of the digital oscilloscope, otherwise it will bring unexpected errors to the measurement.