Overload List
| # | Signature | Description |
|---|---|---|
| 1 | void LowpassToBandpass(TVec *z, TVec *p, double &k, double CenterFreq, double BW); | Frequency transformation from a lowpass to a bandpass filter in s-domain. |
| 2 | void LowpassToBandpass(TMtx *a, TVec *b, TVec *c, double &D, double CenterFreq, double BW); | Convert a lowpass filter prototype in state space form to a bandstop filter. |
Overload 1: void LowpassToBandpass(TVec *z, TVec *p, double &k, double CenterFreq, double BW);
Frequency transformation from a lowpass to a bandpass filter in s-domain.
Transform a lowpass filter prototype in zero-pole form to bandpass filter, where the passband of width BW is centered around the frequency CenterFreq. Assumed sampling frequency is 2. The transformation is defined as ([1], p. 258): s -> (s^2 + W_u W_l)/(s (W_u - W_l))
Wl - lower cutoff frequency Wu - upper cutoff frequency
The routine also adds zeros at 0. It adds one zero, if the lowpass filter order is odd and already has zeros. If the filter does not have zeros, it adds sufficient zeros at 0 to match the order of the lowpass filter.
References:
[1] Theory and application of digital signal processing, Lawrence R. Rabiner and Bernard Gold. Prentice-Hall, 1975
Overload 2: void LowpassToBandpass(TMtx *a, TVec *b, TVec *c, double &D, double CenterFreq, double BW);
Convert a lowpass filter prototype in state space form to a bandstop filter.