Hi Paul.

PLL's of course can introduce phase-noise, as well as remove it.

Certainly if the reference 5 MHz is (phase)noisy then a PLL can clean
that up, but if you multiply it (before cleaning) it gets much worse.  
The multipliers themselves as someone else may chime in, can add to that
I suspect too.

I missed your original question, so did not realise you wanted to
multiply up that far.

Do you subscribe to Dubus?  There's a description of a 122 GHz system in
the current issue, using (from what I can gather) IC's used for
collision avoidance/adaptive-cruise control etc, in modern vehicles..  
PL locked (sort-of) to a GPS PPS source too, phase noisy at 122 GHz, but
good enough for FM voice it seems!

http://www.marsport.org.uk/dubus/last.htm   (Just the front cover.)

There is a sample full issue at 
https://www.dropbox.com/s/6gusksmazh7wmyy/DUBUS412w.pdf?dl=0  (that
describes a 134 GHz transverter)  If you've not come across that
publication before.

73 Paul.

Dave G0WBX


> Subject: Re: [time-nuts] 5 Mhz to 10 Mhz and 25 Mhz
> Message-ID: <B66D51BC70084A0E8B4F9F5BCDB4C373@precision380>
> Content-Type: text/plain;     charset="iso-8859-1"
> Hi Dave  I posted the question as I am not up to speed with the latest
> solutions 
> But I want the lowest phase noise that is easily possible so you might be
> correct as it is to lock up a 10 Ghz receiver but later for a 120 Ghz
> receiver 
> Regards Paul 

Created on and sent from a Unix like PC running and using free and open source 

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
and follow the instructions there.

Reply via email to