Bessel Filter -3dB frequency
15 vues (au cours des 30 derniers jours)
The documentation for besself states: "[b,a] = besself(n,Wo) returns the transfer function coefficients of an nth-order lowpass analog Bessel filter, where Wo is the angular frequency up to which the filter's group delay is approximately constant."
Is there a way to determine what frequency one should input in order to obtain a -3dB amplitude response at a specific frequency?
I realize the bessel filter is used primarily for its phase response and group delay, but I would like to plot the response of several poles of filters all normalized to -3dB at 1 rad/sec for comparison purposes as is often done with the butterworth filter.
Thanks for any help you can provide
filippo tosi le 25 Jan 2022
you can achieve this result by applying some scaling coefficients when designing your filter, as shown here:
For example, in the case of a 3rd order filter with fcut=1000Hz -3dB:
I hope this helps,