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Design >> RF Design >> Ring oscillator Phase noise
https://designers-guide.org/forum/YaBB.pl?num=1272984035

Message started by raja.cedt on May 4^th, 2010, 7:40am

Title: Ring oscillator Phase noise
Post by raja.cedt on May 4^th, 2010, 7:40am

hi,
i have designed a ring oscillator for 2.4g, i got phase noise around 98dbc/hz..i found major contribution from V to I converter? is it my observation correct if so could you please explain reason or please direct me towards good reference

Thanks,
Rajasekhar.

Title: Re: Ring oscillator Phase noise
Post by loose-electron on May 4^th, 2010, 7:07pm

It will be one of many contributors.

What's your circuit architecture?

Title: Re: Ring oscillator Phase noise
Post by raja.cedt on May 4^th, 2010, 8:03pm

hi,
the delay cell has been used here is current steering based inverters, so in this i found V to I is major....

Thanks,
Rajasekhar.

Title: Re: Ring oscillator Phase noise
Post by love_analog on May 5^th, 2010, 12:37pm

If you can upload a schematic that is better.

Remember in LC VCO, the bias current is a major contributor. We put RC filter to remove the bias current contribution.

So what you are seeing is not unreasonable, provided we understand your schematics better.