lhlblue
Member level 3
for a narow-band band pass filter(bpf), the bpf gain has the maximum gain at center frequency f0. now, i want to make the bpf oscillate at f0, how to do it? what i thought is that, if the loop becomes positive feedback, then it can oscillate at the center frequency f0. however, for a second-order bpf (active RC structure with feedback loop), how to make it a positive feedback loop? how to disconnect the bpf loop correctly? some advice will be appreciated, thanks.