The interesting discussions on this site provoked me to try the experiment with
two, fairly identical, Gunn K-band oscillators operating at 24.125 GHz.
Individual power outputs were +18.5 and +19.5 dBm or 0.071W and 0.089W,
respectively. By adding E/H tuners between the oscillator and
On 8 Oct 2014 20:18, paul swed paulsw...@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 went to a users meeting
I have been doing phase combining of power amplifiers for almost 30 years,
professionally.
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
That would only work if the impedance of the source was much lower than the
impedance of the load. That is extremely unlikely in high power systems (at
least in well functioning high power systems), but I heard that modern LNAs do
not always provide the best noise figure when matched, so maybe
Came across this.
Might be relevant.
Cheers,
Corby
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930008868.pdf
a) Greater than 100% power combining efficiencies have been realized as
predicted. This implies that the output power from the combiner is
typically greater than
the sum of the
On 11 Oct 2014 16:25, Didier Juges shali...@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
On 10/11/14, 9:00 AM, cdel...@juno.com wrote:
Came across this.
Might be relevant.
Cheers,
Corby
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930008868.pdf
a) Greater than 100% power combining efficiencies have been realized as
predicted. This implies that the output power from the
Perhaps this is useful
Microwave oscillators will change in both power output and frequency as a
function of
the load impedance. This was first used to characterize magnetrons and
klystrons. When
plotted on a Smith Chart it is called a Rieke Diagram. I later used it with
Gunn Diodes.
You
There's a discussion on the ukmicrowave list about combining the
power from two 10 GHz Gunn oscillators with a magic T. One might
expect to get nearly double the power if the two oscillators are
combined. What people are observing is getting more than double the
power. To quote from
Hi,
I came across this phenomena when transmitting with two 5KW transmitters
via separate parabolic antennas to a satellite.
If the phase of the TXs was correct the received signal at the satellite
was 6db hotter!
I thought at the time that it was due to the power adding in the voltage
mode.
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.
Though the right question is what are they using as power detectors?
When the 2 are combined
Hi
It’s called injection locking. The two oscillators (or what ever) lock up at
exactly the same frequency and some arbitrary phase. Depending on the amplitude
and phase at the sum point, the result can be anything from +6 db to zero
power. Anything that oscillates can injection lock if given
On 8 Oct 2014 20:18, paul swed paulsw...@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
On 8 Oct 2014 20:26, Bob Camp kb...@n1k.org wrote:
Hi
It’s called injection locking. The two oscillators (or what ever) lock up
at exactly the same frequency and some arbitrary phase. Depending on the
amplitude and phase at the sum point, the result can be anything from +6 db
to zero power.
On 8 Oct 2014 20:15, cdel...@juno.com wrote:
Hi,
I came across this phenomena when transmitting with two 5KW transmitters
via separate parabolic antennas to a satellite.
If the phase of the TXs was correct the received signal at the satellite
was 6db hotter!
I can explain that easy
Dr. Dave:
Watch this:
https://www.youtube.com/watch?v=kqFc4wriBvE
Then you can Google injection locked oscillators
--- Graham / KE9H
==
On Wed, Oct 8, 2014 at 12:10 PM, Dr. David Kirkby (Kirkby Microwave Ltd)
drkir...@kirkbymicrowave.co.uk wrote:
There's a discussion on the ukmicrowave
HI
In the case of a magic Tee or a normal power splitter (both passive devices),
the current will not be limited by the combiner or the source. With a proper
combiner, the source will always be running into 50 ohms. You will indeed get 6
db in the in phase sum case.
Bob
On Oct 8, 2014, at
This is certainly an interesting phenomenon. A couple of possible explanations
come to mind.
First, if the pair of Gunn sources are not really locked and are oscillating at
two different frequencies, the resulting voltage envelope would peak at about
double the voltage of either oscillator.
Hi
Most Gunn oscillators have very basic internals. Isolation between the
“oscillator” and the “output” is rarely very good. Injection locking one is
quite easy. It’s often done as the final step in a microwave LO multiplier
chain.
Bob
On Oct 8, 2014, at 6:54 PM, Bruce Hunter via time-nuts
Depends on your detector is it a Voltage or power. 3DBM or 6 DBV are the
same.
Paul
WB8TSL
On Wed, Oct 8, 2014 at 3:07 PM, cdel...@juno.com wrote:
Hi,
I came across this phenomena when transmitting with two 5KW transmitters
via separate parabolic antennas to a satellite.
If the phase of
On 9 Oct 2014 00:26, paul swed paulsw...@gmail.com wrote:
Depends on your detector is it a Voltage or power. 3DBM or 6 DBV are the
same.
Paul
WB8TSL
You are mistaken. A 3 dB increase in signal level is a 3 dB increase -
there's no need to say if power or voltage.
The formula for computing
Corby,
On 10/08/2014 09:07 PM, cdel...@juno.com wrote:
Hi,
I came across this phenomena when transmitting with two 5KW transmitters
via separate parabolic antennas to a satellite.
If the phase of the TXs was correct the received signal at the satellite
was 6db hotter!
I thought at the time
On 8 Oct 2014 23:52, Bob Camp kb...@n1k.org wrote:
HI
In the case of a magic Tee or a normal power splitter (both passive
devices), the current will not be limited by the combiner or the source.
With a proper combiner, the source will always be running into 50 ohms. You
will indeed get 6 db in
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