Today, I want to design a bandpass filter with very narrow bandwidth about 0.05*pi. But I don't have many delays. I just have about 3 delays. If I use a 7-tap FIR, I can't design a suitable filter satisfying the bandwidth required. But if I use a IIR filter that satisfies the bandwidth requirement, the group delays of this filter is about 25 delays.
Can anyone help me to design a filter satisfies both requirements?
Re: Design a digital narrow band bandpass with lilttle taps
Hi Raidum226,
The duration of the impulse response is in the order of the inverse of the bandwidth.
And the group delay is in the order of the duration of the impulse response.
Very narrow band and low group delay are contradictory requirements. It is maybe impossible to satisfy both of them.
Which are your group delay requirements?
Regards
Re: Design a digital narrow band bandpass with lilttle taps
Hi
I am not sure, but may help you.
If sharpness of the filter is not important for you, design a FIR HPF and LPF filter with cutt of frquencies about your requested BPF center frquency and cascade them.