High Pass Filter

What is it about?

The characteristic of Butterworth filter is that the frequency response curve in the pass band is flat to the maximum, and there is no ripple, but it gradually decreases to zero in the stop band. The characteristic of Butterworth filter is that the frequency response curve in the passband is flat to the maximum, without fluctuation, and it gradually decreases to zero in the stopband. On the Bode plot of the logarithmic diagonal frequency of the amplitude, starting from a certain boundary angular frequency, the amplitude gradually decreases with the increase of the angular frequency and tends to negative infinity. The attenuation rate of a first-order Butterworth filter is 6 dB per octave and 20 dB per ten octave. The attenuation rate of the second-order Butterworth filter is 12 decibels per octave, the attenuation rate of the third-order Butterworth filter is 18 decibels per octave, and so on. The Butterworth filter has a monotonically decreasing amplitude diagonal frequency, and is the only filter that maintains the same shape of the amplitude diagonal frequency curve regardless of the order. It is just that the higher the filter order, the faster the amplitude attenuation in the stop band. Other filters have different shapes for higher-order amplitude diagonal frequency diagrams and lower-order amplitude diagonal frequency diagrams.