vco startup circuit

Dear folk,

Does VCO require startup circuit? If it needs the startup circuit, what is its structure?

Thx

wccheng

Usually VCOs doesn't need any startup.
For example, if we think about LC integrated VCOs, the negative resistance should be roughly 3 times higher than equivalent resistance of resonator. This assure that the oscillation starts.
I hope it can help.
Mazz

What About Delay Cell VCO ?