[time-nuts] FW: Injection locking

francesco messineo francesco.messineo at gmail.com
Tue Feb 2 20:37:13 UTC 2010


Hi Murray and all,

Yes, indeed injection locking looks very interesting, and I started
reading around. Seems relatively easy for 22 MHz, but not as easy for
42 MHz (good values should be 6 or 7 MHz, right?).
So far the practical circuit I've seen are few, and this would make me
lean in favour of
direct synthesys which indeed looks easy but forces me to abandon the
old oscillator
circuits.
In the next days I'll try simulating a few ideas with spice and then decide.

First wild idea: how about making two CMOS gate xtal oscillators with
injection locking as you describe? I'd need 2 MHz (10 divided by five)
for the 22 MHz, but how practical would be obtaining the 6 or 7 MHz
from 10 MHz? It would need another oscillator locked....

Thanks

Frank IZ8DWF

On 2/2/10, Murray Greenman <Murray.Greenman at rakon.com> wrote:
>
>
>  -----Original Message-----
>  From: Murray Greenman
>  Sent: Wednesday, 3 February 2010 9:00 a.m.
>  To: 'time-nuts at febo.com'
>  Subject: Injection locking
>
>  Frank,
>
>  Bruce's collection would be a good place to start. Thanks Bruce. Most of
>  the examples relate to microwave applications, where often there is no
>  alternative, but the approach works well on HF and VHF as well, and more
>  importantly, can be achieved with existing oscillators with little
>  modification. The IL technique works with ratios from 20:1 to 1:20 or
>  more, and works well with the GPSDO as a reference.
>
>  My experience is mostly with locking HF crystal oscillators. It works
>  with overtone as well as fundamental oscillators. With an overtone
>  oscillator you can couple into the mode suppression choke. With a tuned
>  tank Pierce oscillator you can couple into the output tank. With a
>  Colpitts, inject into the emitter, collector, or bottom of the crystal.
>  I have made an excellent 10MHz CMOS gate oscillator with 2MHz injection
>  into a varicap acting as one of the crystal load caps (output side).
>
>  Kit VK2LL and others have used 10MHz injection to lock the 20MHz
>  reference in common Icom HF transceivers.
>
>  Arguably the father of the Injection Locking technique would be Vasil
>  Uzunoglu, and I have some references for articles by him. The most
>  readable article is "Synchronous Oscillator outperforms the PLL" (from
>  EDN 1999) http://www.edn.com/contents/images/46326.pdf. It shows how to
>  emitter-lock a conventional Colpitts oscillator. The secret here is to
>  get the bias correct. The test and measurement techniques he uses are a
>  good way to assess performance. Robert Adler (inventor of the TV
>  remote!) also explored the IL technique.
>
>  See:
>
>  http://www.edn.com/contents/images/46326.pdf
>  US Patent 4,355,404 "Carrier Recovery Network for QPSK Modems employing
>  Synchronized Oscillators", Uzunoglu 1982
>  US Patent 6,580,330 "Injection Locked Oscillator Automatic Frequency
>  Centering method and Apparatus", Katznelson & Petrovic 2003 (has a good
>  list of background papers to read)
>  "A study of locking oscillators..." Proc IEEE R Adler 1973
>  http://ieeexplore.ieee.org/iel5/5/31361/31173/01451222.pdf
>  http://en.wikipedia.org/wiki/Injection_locking
>  http://www.amalgamate2000.com/radio-hobbies/radio/synchronous_oscillator
>  .htm
>  http://potol.eecs.berkeley.edu/~jr/research/PDFs/2009-01-ASPDAC-Bhansali
>  -Roychowdhury-GenAdler.pdf
>  http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.130.2535&rep=re
>  p1&type=pdf
>
>  That should keep you busy for a while!
>
>  73,
>  Murray ZL1BPU
>
>
>
>  _______________________________________________
>  time-nuts mailing list -- time-nuts at febo.com
>  To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>  and follow the instructions there.
>



More information about the time-nuts mailing list