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

Design second-order IIR notch digital filter.

A notch filter is a band-stop filter with a narrow bandwidth (high quality factor). It rejects a narrow frequency band and leaves the rest of the spectrum little changed.

  • w0 (float) – Frequency to remove from 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 notch 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


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

Prentice-Hall, 1996