[time-nuts] locking oscillators - an increase in power and/or stability ?
Dr. David Kirkby (Kirkby Microwave Ltd)
drkirkby at kirkbymicrowave.co.uk
Sat Oct 11 16:41:12 UTC 2014
On 11 Oct 2014 16:25, "Didier Juges" <shalimr9 at gmail.com> wrote:
> If I could get 1200W by combining two 300W amplifiers, I would now be
retired and very wealthy indeed.
> Unfortunately, there is no free lunch and unless somehow the Gun
oscillators were delivering more power when connected to the magic T (maybe
because of better matching) than when measured individually, combining two
X W sources will only give you, at best, 2xX W, or 3dB more power.
I see you don't get something for nothing - we are not taking about
I can see a few possible explanations.
1) Instrumentation error.
2) Better match - but that seems unlikely as I would have expected people
to have tried countless way to improve that.
3) Injection locking causes the Gunn diode to oscillate in a different way,
perhaps using different energy levels in the doped semiconductor.
The fact that they have become frequency locked, indicates that their mode
of operation has changed - they are not operating in the way the text books
say that they do.
About 2 decades ago I did an MSc in microwaves & optoelectronics. At that
time I had a pretty good understanding of how Gunn diodes worked, but I
have since forgotten the details. But it doesn't seem totally impossible
that the mode of operation changes to one which is more efficient.
> It does not matter what the combining structure is, magic T, coupler or
I understand what you are saying, but it is hard to dismiss the possibility
it is true given several people have observed this. Just because it doesn't
fit into our established theories, doesn't mean it can not happen.
It is not breaking any laws of physics - the overall efficiency is well
> Didier KO4BB
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