[time-nuts] locking oscillators - an increase in power and/or stability ?

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Wed Oct 8 16:42:10 EDT 2014


On 8 Oct 2014 20:18, "paul swed" <paulswedb at gmail.com> wrote:
>
> David the locking makes sense but the other numbers do not make sense.
> Combined best case would be +3 DBm also you say the current on the diodes
> goes down. More power for less power in is not adding up.

I agree. However, the fact that the current goes down a mA is less than 1%.

With a Gunn diode, it has a negative dynamic resistance.  An increase in
voltage causes a drop in current.

> Though the right question is what are they using as power detectors?

I don't know.  It is being discussed on ukmicrowaves
A X-band Gunn Oscillator would almost certainly use WR90 waveguide which
has a cutoff frequency of about 6.5 GHz, so one could not get any lower out
of waveguide.

> When the 2 are combined there could be a large lower frequency mix
product.

I don't see how it could propagate in waveguide.

> Broad band detectors just collect all of the stuff and add it up.

Does injection locking lead to increased frequency stability?  I guess the
effects of small temperature changes at one oscillator,  which would
ordinarily cause a change in frequency,  might tend to opposed by the
other. Only if they want to move in the same direction they shift more
easily.

> Regards
> Paul
> WB8TSL

Dave



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