Wolframore
- Joined Jan 21, 2019
- 2,610
Sounds like a rose with a different name... perhaps its a little bit like the difference between a zener and a transil or TVS
The two devices have completely different physics as the physical mechanism for negative resistance that limit the usefulness of each in certain types of applications. A Gunn device is not a junction diode, it's a bulk effect device the doesn't have the same storage time delays of PN junctions and has a large mass Gunn effect substrate that allows for much higher power devices than tunnel diodes.Sounds like a rose with a different name... perhaps its a little bit like the difference between a zener and a transil or TVS
That's the thing, negative resistance is a characteristic that can be intrinsic to device operation or it can be a dynamic effect caused by a system of components like the Four-Layer Diode using transistors.Yep hence the diagrams. I had never heard of Gunn diodes before but it looks like similar in characteristics... anyhow.
Good find, that is really cool and now that I’ve read it it makes perfect sense. Not sure how good of a replacement this is but there’s the ability to tune it.That's the thing, negative resistance is a characteristic that can be intrinsic to device operation or it can be a dynamic effect caused by a system of components like the Four-Layer Diode using transistors.
http://www.rfcafe.com/references/el...ve-resistance-electronics-world-june-1969.htm
So, I built the circuit as shown in the picture below.If you can't get hold of tunnel diodes, I've been having a play on LTspice and found that an output signal similar to that shown by Bordodynov in post #9 can be obtained by use of a pair of NPNs (or PNPs) cross-coupled :-
View attachment 186973
by Duane Benson
by Jake Hertz
by Jake Hertz