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Design >> RF Design >> injection locking
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Message started by aaron_do on Sep 12^th, 2006, 5:57pm

Title: injection locking
Post by aaron_do on Sep 12^th, 2006, 5:57pm

Hi all,

does anybody have any good resources or a good explanation of injection locking in Oscillators? I've found formulae on the locking range but all papers i've read so far seem to take for granted that it works. Does anybody know why?

Aaron

Title: Re: injection locking
Post by ACWWong on Sep 16^th, 2006, 3:05am

try:
http://www.ee.ucla.edu/~razavi/papers/Conferences/RCICC2003.pdf

Title: Re: injection locking
Post by mobil on Sep 19^th, 2006, 8:28pm

Yes, that's Razavi's paper is quite good! And I know a PhD thesis about that, which is

http://bwrc.eecs.berkeley.edu/Publications/2004/THESIS/BLimketkai/BLimketkaiPhdThesis.pdf

if you like maths and non-linear analysis method very much.

This paper is alos very good:

H.R.Rategh and T. H. Lee,
``Superharmonic injection-locked frequency dividers,"
\emph{IEEE J. Solid-State Circuits}, vol. 34, pp. 813-821,
June 1999.

But I suppose the result they've got are very similar.

Title: Re: injection locking
Post by RFICInDaHouse on Oct 9^th, 2006, 8:31pm

yeah, all injection-locked frequency dividers, injection-locked oscillators have the same operation and was derived by Miller in the 1940s! (He actually proposed the regenerative frequency divider). In principle, an oscillator running at f0, can be injection locked to an external stimulus at f0 +/- df, where df is the locking bandwidth. The locking bandwidth has its origion in satisfying Barkausen's criterion. As you move away from the resonant frequency, the load impedanance goes down and so does the loop gain. That's why the higher the tank Q, the faster the tank impedance will drop, and the smaller the locking bandwidth..... I don't like the math of it, after all we are engineers! and we seek intuition.