Passband ripple in butterworth filter

1. Does Butterworth filter have ripples?
2. What is the passband ripple?
3. Why is there ripple in the passband and in the stopband?
4. What is passband ripple Chebyshev?

Does Butterworth filter have ripples?

The Butterworth filter is the best compromise between attenuation and phase response. It has no ripple in the passband or the stopband, and because of this it is sometimes called a maximally flat filter.

What is the passband ripple?

Passband Ripple and Stopband Attenuation. In many applications, you can allow the gain in the passband to vary slightly from unity. This variation in the passband is the passband ripple, or the difference between the actual gain and the desired gain of unity.

Why is there ripple in the passband and in the stopband?

Passband ripple occurs in the high-gain region of a higher-order filter or amplifier's transfer function, and looks like some variations in the output gain. The same applies to the phase on the output. In effect, the two are not smooth functions of frequency. Ripple can also appear in the stopband in these circuits.

What is passband ripple Chebyshev?

In the passband, the Chebyshev polynomial alternates between -1 and 1 so the filter gain alternate between maxima at G = 1 and minima at . The ripple factor ε is thus related to the passband ripple δ in decibels by: At the cutoff frequency the gain again has the value.