How to choose the value of the L and C when design a VCO?

There are many kinds of combination of L and C when desing a VCO at a certain frequency, So how to choose one for the best performance? what is the criteria to follow?

1. Choose a desired configuration: commonly either Colpitts or Clapp.

2. Use the design equation regarding to the configuration for your L and C.

I am now design a LC VCO, so what equations should I follow?

Hi,

I attach below a book about oscillators, hopefuly that will help to you!

David

I think for better phase noise, L should be choosed for largest Q.

For best performance a few points to note:

Loaded Q high, BUT you must ensure reliable starting. High loaded Q will need more gain (loop gain) from the active part to start due to higher insertion loss.

Once started prevent saturation.

Design for highest output level. This will lower the phase noise

Tap the energy from the resonator with a high input impedance buffer amp.