SciPy

scipy.signal.besselap

scipy.signal.besselap(N)[source]

Return (z,p,k) for analog prototype of an Nth order Bessel filter.

The filter is normalized such that the filter asymptotes are the same as a Butterworth filter of the same order with an angular (e.g. rad/s) cutoff frequency of 1.

Parameters:

N : int

The order of the Bessel filter to return zeros, poles and gain for. Values in the range 0-25 are supported.

Returns:

z : ndarray

Zeros. Is always an empty array.

p : ndarray

Poles.

k : scalar

Gain. Always 1.