Conversion gain from any node in LC VCO to the phase noise

[boshiouke]

Hi,

Does anyone know how to simulate for the conversion gain from any node in LC VCO to the phase noise using Spectre RF? Thank you.

 

[micasa]

Re: Conversion gain from any node in LC VCO to the phase noi

Make it alive

I have the same question.

If anyone knows the answer, please let us know.

Thanks in advance.

Best regards

 

[BigBoss]

Conversion gain of a VCO ??? What does it mean ??
The VCO's are positive feedback amplifiers, so they are unstable so that, the parameter conversion gain has no sense...

 

[micasa]

Re: Conversion gain from any node in LC VCO to the phase noi

In this paper: A filtering technique to lower LC oscillator phase noise, Emad Hegazi, H. Sjoland, A. A. Abidi, IJSSC, Dec. 2001.

The authors showed the simulation results of conversion gain from voltage noise at any node in the oscillator to phase noise.

For example, the following figure plots the simulated conversion gain from gate-refered voltage noise in one of the differential pair FETs to phase noise, versus discrete frequencies of voltage noie which will produce close in phase noise