scipy.signal.lp2bp_zpk¶

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 bandpass filter with center frequency wo and bandwidth bw from an analog lowpass 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 bandpass filter transfer function.
 p : ndarray
Poles of the transformed bandpass filter transfer function.
 k : float
System gain of the transformed bandpass filter.
Notes
This is derived from the splane 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.
New in version 1.1.0.