How exactly do I find this value for the feedback fraction Beta? Thank you. omega_0 here is the natural frequency calculated as omega_0 = 1/RC and s is the complex frequency.
It`s very simple:
The feedback factor is nothing else than a frequency-dependent voltage divider Z2/(Z1+Z2) with Z1 as a series combination and Z2 as a parallel combination of the given impedances (R resp. 1/wC).
This passive part forms the most simple form of an RC-bandpass.