[time-nuts] Injection locking interconnect
Guys, I am looking for info on injection locking. I have been searching around for info. I found an article that probably answers my question but I can't get to it. http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED2.1fulltext/11-24pp%20GC05-06%20%28Rajput%29.pdf Can anyone give me a reference regarding the required interconnection? I understand the ho and why... I just am wondering how you make sure locking occurs in the right direction. In other words the target oscillator gets locked to the injected signal and not the other way around. The application is a synthesized frequency source injection locking a tcxo to improve phase noise. Doc KX0O Sent from my iPad ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Injection locking interconnect
On 6/28/12 3:07 PM, Bill Dailey wrote: Guys, I am looking for info on injection locking. I have been searching around for info. I found an article that probably answers my question but I can't get to it. http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED2.1fulltext/11-24pp%20GC05-06%20%28Rajput%29.pdf Can anyone give me a reference regarding the required interconnection? I understand the ho and why... I just am wondering how you make sure locking occurs in the right direction. In other words the target oscillator gets locked to the injected signal and not the other way around. The application is a synthesized frequency source injection locking a tcxo to improve phase noise. What you might look for is literature on coupled oscillators, for which there is quite a lot. If you have something like an isolator or other non-reciprocal device, then you can make sure that power flows mostly from good to bad. I believe, also, that it has to do with the relative Q of the two oscillators. The higher Q (e.g. stiffer) will drive the lower (softer), for equal powers transferred in each direction and equal powers out of the oscillators. One way to look at it is that there is more stored energy in the resonator of the higher Q oscillator (Q = stored energy/output energy), so the contaminating energy has a smaller relative effect. One can also demonstrate this nicely with a pair of coupled pendulums with different weights on the bob. (strings on a broomstick work nicely) with equal weights, the power couples back and forth periodically. With one heavy and one light, the light one always follows the heavy. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Injection locking interconnect
Bill, On 06/29/2012 12:07 AM, Bill Dailey wrote: Guys, I am looking for info on injection locking. I have been searching around for info. I found an article that probably answers my question but I can't get to it. http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED2.1fulltext/11-24pp%20GC05-06%20%28Rajput%29.pdf Can anyone give me a reference regarding the required interconnection? I understand the ho and why... I just am wondering how you make sure locking occurs in the right direction. In other words the target oscillator gets locked to the injected signal and not the other way around. If you have two oscillators of the same frequency, these may injection-lock to each other, in which case the injection locking causes mutual synchronisation, which is a little forgotten research field all on it's own. This is a great starting point on injection locking that fellow time-nut Bruce Griffith wrote and collected references for: http://www.ko4bb.com/~bruce/InjectionLocking.html The application is a synthesized frequency source injection locking a tcxo to improve phase noise. If you have a reference being of in a completely different frequency, it will have no or much weaker coupling to your oscillator you try to lock, than the direction you want to achieve. That helps. You can actually use injection locking to aid in PLL locking. This have been shown, see Wolaver's PLL book. I've mentioned this previously on the list, so it may be found... Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Injection locking interconnect
On 6/28/12 3:22 PM, Magnus Danielson wrote: Bill, On 06/29/2012 12:07 AM, Bill Dailey wrote: Guys, I am looking for info on injection locking. I have been searching around for info. I found an article that probably answers my question but I can't get to it. http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED2.1fulltext/11-24pp%20GC05-06%20%28Rajput%29.pdf Can anyone give me a reference regarding the required interconnection? I understand the ho and why... I just am wondering how you make sure locking occurs in the right direction. In other words the target oscillator gets locked to the injected signal and not the other way around. If you have two oscillators of the same frequency, these may injection-lock to each other, in which case the injection locking causes mutual synchronisation, which is a little forgotten research field all on it's own. This is a great starting point on injection locking that fellow time-nut Bruce Griffith wrote and collected references for: http://www.ko4bb.com/~bruce/InjectionLocking.html I've always wondered about injection locking a 2.45 GHz oven magnetron, and whether you could use it to do something like FM. The magnetron is a pretty crummy source phase noise wise, but is that because of low Q (and the frequency is just unstable, which locking would help) or because the amplification mechanism is noisy (in which case locking doesn't help). That is, is injection locking more like a MOPA or a locked power oscillator. (we're talking oven magnetrons here, not radar magnetrons for doppler radar which are actually designed for injection locking, etc. ) There's an interesting paper out there using a bunch (half dozen?) magnetrons as a microwave weed killer, where they all locked to each other, so the power was appropriately combined with minimal loss. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Injection locking interconnect
Don't run it over your toes! snip There's an interesting paper out there using a bunch (half dozen?) magnetrons as a microwave weed killer, where they all locked to each other, so the power was appropriately combined with minimal loss. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Injection locking interconnect
On 06/29/2012 01:37 AM, Jim Lux wrote: On 6/28/12 3:22 PM, Magnus Danielson wrote: Bill, On 06/29/2012 12:07 AM, Bill Dailey wrote: Guys, I am looking for info on injection locking. I have been searching around for info. I found an article that probably answers my question but I can't get to it. http://www.oldcitypublishing.com/FullText/JAPEDfulltext/JAPED2.1fulltext/11-24pp%20GC05-06%20%28Rajput%29.pdf Can anyone give me a reference regarding the required interconnection? I understand the ho and why... I just am wondering how you make sure locking occurs in the right direction. In other words the target oscillator gets locked to the injected signal and not the other way around. If you have two oscillators of the same frequency, these may injection-lock to each other, in which case the injection locking causes mutual synchronisation, which is a little forgotten research field all on it's own. This is a great starting point on injection locking that fellow time-nut Bruce Griffith wrote and collected references for: http://www.ko4bb.com/~bruce/InjectionLocking.html I've always wondered about injection locking a 2.45 GHz oven magnetron, and whether you could use it to do something like FM. The magnetron is a pretty crummy source phase noise wise, but is that because of low Q (and the frequency is just unstable, which locking would help) or because the amplification mechanism is noisy (in which case locking doesn't help). That is, is injection locking more like a MOPA or a locked power oscillator. (we're talking oven magnetrons here, not radar magnetrons for doppler radar which are actually designed for injection locking, etc. ) I also noted that microwave ovens is matching up to the 2,48832 GBd rate of SDH STM-16, which is kind of interesting fact, since that also means that frequency synthesis is fairly well established. Using a 155,52 MHz or 622,08 MHz oscillator is all very standard stuff, and a nice intermediary frequency would be 19,44 MHz. All being off the shelf stuff. The challenge would be to get a decent microwave input for injection feed. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
