[time-nuts] injection locking

Joop lous at xs4all.nl
Wed Feb 10 20:26:43 UTC 2010

Yes, I wrote I searched for that too. This indeed is one circuit I found.

At first glance the biasing does not give me the impression it might be a
very good oscillator by itself. But then again, that might be a requirement
in order to allow it to lock to another signal.
James G1PVZ wanted to see how far he could pull it (>10% it seems). And
tested how it tracked FM modulation.

For purposes of a very pure harmonic frequency one might have to start
with a better oscillator.
I played a bit with SPICE to see if I could make a high Q oscillator lock,
but with limited success. Perhaps it needs much more time to start locking.
I guess building something and measure it might be faster.


>you may also search for "synchronous oscillator". You will find for
>Best regards
>> -----Ursprungliche Nachricht-----
>> Von: time-nuts-bounces at febo.com 
>> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Joop
>> Gesendet: Mittwoch, 10. Februar 2010 13:50
>> An: time-nuts at febo.com
>> Betreff: [time-nuts] injection locking
>> >You can even build an injection locked divide by 5 stage. 
>> Choosing the 
>> >right oscillator topology and injection method allows high level 
>> >injection to be used with an LC oscillator.
>> >
>> >Bruce
>> >
>> Are there references to some practical circuits? That would be great.
>> A google search on "injection locking" and "synchronous 
>> oscillator" results in a lot of conceptual descriptions but 
>> nothing that one can build, try out and study. Maybe some of 
>> the scientific articles or books contain circuits, but I am 
>> not a IEEE member.
>> Cheers,
>> Joop

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