I was reading on a book (High-Frequency Oscillator Design for Integrated Transceivers, J. van der Tang, Dieter Kasperkovitz, Arthur H.M. van Roermund) this paragraph about the start-up condition for an oscillator:
Now, I may do a small signal analysis of this circuit at open loop, find the expression of the loop gain, and size the components in order to make its absolute value greater than one. But, which is the mechanism that will reduce it once the oscillator has started? Is it automatic? How can I size the components in order to make it exactly equal to 1?