cupyx.scipy.signal.lp2bp_zpk#

cupyx.scipy.signal.lp2bp_zpk(z, p, k, wo=1.0, bw=1.0)[source]#

Transform a lowpass filter prototype to a bandpass filter.

Return an analog band-pass filter with center frequency wo and bandwidth bw from an analog low-pass filter prototype with unity cutoff frequency, using zeros, poles, and gain (‘zpk’) representation.

Parameters:
  • z (array_like) – Zeros of the analog filter transfer function.

  • p (array_like) – Poles of the analog filter transfer function.

  • k (float) – System gain of the analog filter transfer function.

  • wo (float) – Desired passband center, as angular frequency (e.g., rad/s). Defaults to no change.

  • bw (float) – Desired passband width, as angular frequency (e.g., rad/s). Defaults to 1.

Returns:

  • z (ndarray) – Zeros of the transformed band-pass filter transfer function.

  • p (ndarray) – Poles of the transformed band-pass filter transfer function.

  • k (float) – System gain of the transformed band-pass filter.

Notes

This is derived from the s-plane substitution

\[s \rightarrow \frac{s^2 + {\omega_0}^2}{s \cdot \mathrm{BW}}\]

This is the “wideband” transformation, producing a passband with geometric (log frequency) symmetry about wo.