I deal with the problem of the synthesis of the filter with the requirements of both the frequency and time characteristics.
Now there is a filter that meets the requirements. Roughly speaking the requirements are as follows:
FIR Low Pass
- Fpass ~ 0.0(3) (* pi rad/sample)
- Fstop ~ 0.1(6) (* pi rad/sample)
- bandwidth irregularity of ~ 1e-3 (maybe ~ 1e-2) dB
- ~ -40 dB suppression
- Overshoot in step response ~ 4% (transition time ~ 1e-2 ms)
I would like to know about the possibilities of such a synthesis (I’m with filterDesigner in the matlab failed, tried free tools - Iowa Hills) or at least about the transformation of the finished filter into a narrower (Fpass = 0.025, Fstop = 0.125) (Matlab can do this, but only IIR is obtained).