Document

scipy 1.8.0 Pypi GitHub Homepage

lp2bp(b, a, wo=1.0, bw=1.0)

Return an analog band-pass filter with center frequency :None:None:`wo` and bandwidth :None:None:`bw` from an analog low-pass filter prototype with unity cutoff frequency, in transfer function ('ba') representation.

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 :None:None:`wo`.

Parameters

b : array_like: Numerator polynomial coefficients.
a : array_like: Denominator polynomial coefficients.
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

b : array_like: Numerator polynomial coefficients of the transformed band-pass filter.
a : array_like: Denominator polynomial coefficients of the transformed band-pass filter.

Transform a lowpass filter prototype to a bandpass filter.

Examples

>>> from scipy import signal
... import matplotlib.pyplot as plt

>>> lp = signal.lti([1.0], [1.0, 1.0])
... bp = signal.lti(*signal.lp2bp(lp.num, lp.den))
... w, mag_lp, p_lp = lp.bode()
... w, mag_bp, p_bp = bp.bode(w)

>>> plt.plot(w, mag_lp, label='Lowpass')
... plt.plot(w, mag_bp, label='Bandpass')
... plt.semilogx()
... plt.grid()
... plt.xlabel('Frequency [rad/s]')
... plt.ylabel('Magnitude [dB]')
... plt.legend()

See :

Back References

The following pages refer to to this document either explicitly or contain code examples using this.

scipy.signal._filter_design.lp2hp scipy.signal._filter_design.lp2lp scipy.signal._filter_design.lp2bp_zpk scipy.signal._filter_design.lp2bs scipy.signal._filter_design.lp2bp scipy.signal._filter_design.bilinear

Local connectivity graph

Hover to see nodes names; edges to Self not shown, Caped at 50 nodes.

Using a canvas is more power efficient and can get hundred of nodes ; but does not allow hyperlinks; , arrows or text (beyond on hover)

SVG is more flexible but power hungry; and does not scale well to 50 + nodes.

All aboves nodes referred to, (or are referred from) current nodes; Edges from Self to other have been omitted (or all nodes would be connected to the central node "self" which is not useful). Nodes are colored by the library they belong to, and scaled with the number of references pointing them