[time-nuts] Current state of optical clocks and the definition of the second

Mike Feher mfeher at eozinc.com
Wed Jan 14 21:47:23 EST 2015


Hi -

I agree with what you stated, however, I am not sure that at real low levels they are actually discernible. Regards - Mike 

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Bob Camp
Sent: Wednesday, January 14, 2015 6:14 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Current state of optical clocks and the definition of the second

Hi

More or less by definition:

AM noise has the sidebands in phase, PM noise has the sidebands out of phase. PM adds to no envelope power, AM adds to the envelope power. If you have purely random noise, half of the power is AM, half is PM by this approach. If you have what is effectively a SDR (high speed ADC(s), decimators, cross correlation …) doing your phase noise measurement, figuring out sidebands and phase is part of the process. With an old style single mixer approach, you switch your operating point on the mixer.

Bob




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