DPO6000, MPO6000 Series Digital Fluorescent Oscilloscope Product Manual V1.3 The following two measures can avoid aliasing: 1. Increase the sampling frequency to more than twice the highest signal frequency; 2. Introduce or increase the parameters of the low-pass filter; the low-pass filter is often called an anti-aliasing filter. Anti-aliasing filters can limit the bandwidth of the signal to meet the conditions of the sampling theorem. In theory, this is feasible, but it is impos- sible in practice. Because filters cannot completely filter out signals above the Nyquist frequency, there is always some "small" energy outside the bandwidth required by the sampling theorem.
However, anti-aliasing filters can make these energies small enough to be negligible. Waveform distortion Due to the low sampling rate, some waveform details are missing, which makes the waveform displayed by the oscilloscope to be different from the actual waveform. Waveform miss Because the sampling rate is too low, the waveform when reconstructing the sampled data does not reflect all the actual signals. 21