Hello all,
What is the theory behind selecting the right max time step for FFT analysis?
I always assumed that the max time step should be selected depending on the highest frequency resolution one might desire from the FFT.
However, I noticed that I need to further reduce the max time step to avoid artifacts which appear as higher order harmonics.
To analyse a simple audio circuit, I typically use a 1 kHz sine input signal, run a? transient (duration = 300 ms, max time step = 10 us).
I checked my simulation setup with a simple circuit (2 voltage sources in series with a resistor, 1st source 1 kHz and second source 4 kHz). I observed that I have to reduce the max time step to at least 2 us in order to keep the artifacts below 130 dB.
I would be very interested to better understand the theory behind!
Thank you in advance,
Jos
