Question

What are the two requirements for oscillation?

Answer 1

The two requirements for oscillation are:

1. To provide the necessary gain for the signal, the oscillator requires amplification.
   1.1 The loop's losses (generated by the feedback circuit) should be precisely balanced by the loop's gain (supplied by the amplifier).
   1.2 The losses need an amplifying circuit like RC and LC to control the frequency of oscillation.
2. The oscillator requires sufficient regenerative feedback to sustain oscillation.
   2.1 Positive or negative feedback is given to the system depending on whether it is in-phase (positive feedback) or out-of-phase (negative feedback) with the initial input signal. 2.2 To obtain the sustained oscillations, the multiple of the voltage gain and the feedback gain must be one or greater than one.