LMGTFY. "Degenerate parametric amplifier" varactor
Result #2:
See Figure 23 on P. 66 for an interesting degenerate paramp circuit, and Section 2.3.2 starting on P. 30 for discussion.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
The active element of an oscillator, fed from a power supply, adds enough energy to overcome losses in the resonator.
A parametrically pumped resonator does that. The words that you use don't change the reality. If you define an oscillator as not having a gain element, then it doesn't for you.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
And this one works down to a Q of 10, and works well at a Q of 19 (as shown).
Cheers
Phil Hobbs
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-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
I don't know why you include his thesis. He is talking about standard parametric upconverters using two input signals, similar to a mixer. These are well-known and understood.
We are talking about frequency halver using a single input frequency. I refer you to Jeroen or Legg's circuits.
I am waiting for a list of commercial vendors of frequency halvers that you said could be bought with no problem. I am not talking about a standard parametric down converter that requires a pump signal.
That does have DC current in the diodes, as do some of the other circuits posted here. There may be something else going on, some SRD effect maybe. Especially in the divide by 2 or 3 circuits that output the occasional big spike.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Thanks! Now we are talking. I had come across several dual varactor frequency halvers using microstrip transmission lines at GHz frequencies.
Your circuit moves this down to a lower frequency where standard components can be used.
Note that ordinary diodes won't work. It needs the varactors. And it needs two of them, not just one like Jeroen and Legg's circuits.
It works only at half the input frequency. It won't work at F/3 or F/4.
Now the trick will be to find the phase noise. If it can divide the input frequency with lower phase noise than a regular d-flop, it could have some significant application in my work.
Single varactor or diode circuits : Out. Hobbs Halver : In.
Thanks.
OK, there is no feedback and no gain.
It doesn't. Words mean things.
Well...
The active element certainly has gain. The oscillator itself has no definable gain because it has no input.
Yes, and you can play with them endlessly.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
This is a joke version of the circuit offered by Jeroen. It uses a generic rectifier with low Cj.
Realistic source impedance in the 'pump' is enough to kill it.
Aren't models great?
RL
We're not alone. Wiki thinks that a pendulum is an oscillator.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Unfortunately, I found that silicon varactors are quite noisy at microwave frequencies. GaAs are quieter but expensive. This probably kills the dual varactor divider, but this piece of information has a direct bearing on using varactors in vco's at microwave frequencies. It has probably saved me a great deal of work and wasted time and money, so it was well worth the search.
It is common knowledge in electronics; that oscillators don't.
RL
On a sunny day (Wed, 11 Nov 2015 20:01:04 GMT) it happened Bruce S wrote in :
flipflops... Or did you mean something else?
;-)
(I take no side on this, but am curious)
flipflops
:-)
BTW there are other ways, old organs had neons. These guys talk about using solid state diodes named DIAC: http://
Never tried that, but also a 2 terminal device.
There is more I am sure.
Magamp Flipflop!!
-- Grizzly H.
On a sunny day (Thu, 12 Nov 2015 06:36:37 -0500) it happened muesly wrote in :
There exists relays that you can set with a pulse to one state or the other (bipolar). Sort of a set-reset flipflop. Long time ago I made an oscillator for Christmas lights with a relay and a capacitor, bended the contacts a bit to get the right on-off time.
If it must be a solid state diode, I wonder if you can use photoelectric effect (change in reverse conductance diode) and some galvanometer vane that intercepts the light to make an oscillator (without mechanical contacts).
Have you ever tried pumping up a swing by standing on the seat and just moving your center of mass up and down? You need a bit of motion for it to work.. after which you are going like gang busters in no time. Careful not to fall off! (I'm still a kid at heart.)
George H.
There are solar powered knick knacks, some of which involve an oscillating vane covering a photovoltaic device.
Google "solar powered knick knack"
-- Grizzly H.
That's when they lose meaning. See: leftist (doublespeak)
On a sunny day (Thu, 12 Nov 2015 11:02:45 -0500) it happened muesly wrote in :
Cool :) How 'bout this:
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