I have a design task of creating a Phase Shift Oscillator with a frequency of 5kHz, which I have done now (using a 3 stage RC ladder network and an inverting operation amplifier (with gain of 29)), as an extension to this I would like to remove unwanted frequencies from this circuit, which are visible when viewing a FFT (fast fourier transform) any tips/guidance/circuit topologies in order to add to this oscillator would be much appreciated .

I personally would also love to know how could I adjust the oscillation so that it occurred between two voltage this more out of curiosity

Thanks

Sunday