how to measure the Q-factor of oscillators

[nauwaf]

if any body Knows how to measure the Q-factor of an oscillator, please help me.
i have a DRO operating at 6.3GHz. i am not asking how to measure the Q-factor of the dielectric resonator i want the Q-factor of the whole oscillator.
thanks

 

[flyhigh]

Hi,

could you explain what is the Q factor of the oscillator?

flyhigh

 

[teteamigo]

A spectrum analyser and measure the one half power to central frequency.

Q=central frequency/bandwidth


Bandwith in the sense of 2*(fcentral-f at half power)

f=frequency

 

[biff44]

I do not think so. If you had a mesfet oscillator vs a bipolar oscillator, that method would yield a 20 dB different "Q factor", irregardless of the actual loaded Q.

The best way to measure the loaded Q of the entire oscillator would be to injection lock it to a signal and see how far you can pull it. The ammount of frequency pulling is inversely proportional to Q.

 

[nauwaf]

thank you
i just got it so i cant measure it but i can have a feel of it by the pull push method. by varying the load and the power supply. thanks