cupyx.scipy.signal.iirpeak(w0, Q, fs=2.0)[source]#

Design second-order IIR peak (resonant) digital filter.

A peak filter is a band-pass filter with a narrow bandwidth (high quality factor). It rejects components outside a narrow frequency band.

  • w0 (float) – Frequency to be retained in a signal. If fs is specified, this is in the same units as fs. By default, it is a normalized scalar that must satisfy 0 < w0 < 1, with w0 = 1 corresponding to half of the sampling frequency.

  • Q (float) – Quality factor. Dimensionless parameter that characterizes peak filter -3 dB bandwidth bw relative to its center frequency, Q = w0/bw.

  • fs (float, optional) – The sampling frequency of the digital system.


b, a – Numerator (b) and denominator (a) polynomials of the IIR filter.

Return type:

ndarray, ndarray

See also



Sophocles J. Orfanidis, “Introduction To Signal Processing”,

Prentice-Hall, 1996