Phase Noise - RF Cafe Forums

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satish.1979
Post subject: Phase Noise Posted: Tue Oct 03, 2006 9:45 am

Captain

Joined: Tue Oct 03, 2006 3:03 am
Posts: 11
Location: India
Q1
why flicker noise contributes to the phase noise, not the thermal noise in oscillators?


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Stephen
Post subject: Posted: Tue Oct 03, 2006 10:11 am

Captain

Joined: Wed Jun 21, 2006 8:33 pm
Posts: 21
Location: Queen Creek, Arizona
Both flicker and thermal noise increase the phase noise. The issue is that flicker noise in MOS devices, can be very large, upto the corner frequency (the frequency at which flicker and thermal noise have equivalent magnitudes). In MOS devices the corner frequency can extend to the low the high KHz or low MHz, while in bipolar it usually stays below the low 100's of Hz.

Ergo, because flicker noise tends to have much larger magnitudes, especially at lower frequencies, many designers choose to ignore thermal noise and state that flicker is the only phase noise contributor. This is in fact a mistake; its simply that Flicker noise tends to dominate. But both contribute to phase noise degradation, its just a question of how much.

_________________
CMOS RF and Analog ESD Specialist!
www.srftechnologies.com

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satish.1979
Post subject: ThanksPosted: Wed Oct 04, 2006 2:05 am

Captain

Joined: Tue Oct 03, 2006 3:03 am
Posts: 11
Location: India
Hello Stephen

Thanks for your brief explanation.
Now I am clear about the phase noise in oscillator.

suggest me some books or articles on oscillator design

Have a nice day


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IR
Post subject: Posted: Tue Oct 10, 2006 6:40 am

Site Admin


Joined: Mon Jun 27, 2005 2:02 pm
Posts: 373
Location: Germany
Hello,

There are some nice articles in www.rfic.co.uk website:

http://www.odyseus.nildram.co.uk/RFMicr ... llator.pdf

http://www.odyseus.nildram.co.uk/RFMicr ... Basics.pdf

http://www.odyseus.nildram.co.uk/System ... eNoise.pdf

Good luck!

_________________
Best regards,

- IR


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Stephen
Post subject: Posted: Wed Oct 11, 2006 1:41 pm

Captain

Joined: Wed Jun 21, 2006 8:33 pm
Posts: 21
Location: Queen Creek, Arizona
IR,
That is a great website. Thanks for the link; I had never stumbled across the site previous.

_________________
CMOS RF and Analog ESD Specialist!
www.srftechnologies.com

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fred47
Post subject: Book on Oscillator DesignPosted: Thu Oct 19, 2006 5:51 pm

General


Joined: Wed Feb 22, 2006 3:51 pm
Posts: 104
Hi!
One of the most available books on oscillator design is by Randall Rhea, entitled Oscillator Design and Computer Simulation.

Good Luck!
Fred



Posted  11/12/2012