[time-nuts] How to measure phase noise of HCMOS oscillators?

Magnus Danielson magnus at rubidium.dyndns.org
Wed Mar 12 06:53:51 EDT 2014

On 12/03/14 10:57, Anders Time wrote:
> Thanks a lot for the input!
> I will try to use the LMH6702 as buffer.
> The correct way to measure the HCMOS oscillator would probably be to use a
> high impedance buffer with very low noise, to simulate driving a 10pF load
> or so. But I guess that is not easy to do. The LMH6702 voltage noise is
> probably low enough, but I do not know if it is possible to bias the HCMOS
> signal so it matches the LMH6702 input voltage range without increasing the
> noise level.
> I´m using a double balanced mixer form mini circuits as phase detector that
> can take 14dBm signals and a SRS FFT analyzer to measure the noise. The
> oscillator that I´m measuring is a 100MHz Crystek.

OK. What is the other signal to the mixer? What is the ref?
A known quiet 100 MHz? Another Crystek? Delayed version of itself? 
Oscillator locked to the input?


More information about the time-nuts mailing list