Correcting large variable dc bias in signal FFT

1. How do you remove DC bias from a signal?
2. What is DC bias signal?
3. Why remove DC offset?

How do you remove DC bias from a signal?

An electrical DC bias will not pass through a transformer or capacitor; thus a simple isolation transformer or series-wired capacitor can be used to block or remove it, leaving only the AC component on the other side.

What is DC bias signal?

DC biasing is setting up a circuit to operate a transistor at a desired operating point on its characteristic curve. Three bias networks for the common emitter amplifier are shown in figure 5.7.

Why remove DC offset?

The resulting vertical shift of the waveform position is clearly visible in the Audio File Editor. DC offset can also cause crackling sounds at the start and end of the audio region during playback. Removing DC offset centers the waveform around the zero amplitude line.