Negative differential resistance:

http://phys.org/news/2017-01-physicists-decades-old-scientific-mystery-negative.html

Something new on the horizon, at least a new way to actually manufacture this effect.

Originally posted by sonhouse
http://phys.org/news/2017-01-physicists-decades-old-scientific-mystery-negative.html

Something new on the horizon, at least a new way to actually manufacture this effect.

How do you think solid state RADAR works?

Originally posted by DeepThought
How do you think solid state RADAR works?

Is there some major difference between solid state radar and the old tubed variety? Not sure what you are getting at here. You ship a quick pulse out your antenna, wait for a return some microseconds or milliseconds or nanoseconds for short range radar or much longer times for radio astronomy, like a few minutes for a pulse to return from asteroids and planets in the solar system.

It uses standard microwave components like Klystrons and Magnetrons and reverse magnetrons and such, not exactly esoteric phenomena.

Originally posted by sonhouse
Is there some major difference between solid state radar and the old tubed variety? Not sure what you are getting at here. You ship a quick pulse out your antenna, wait for a return some microseconds or milliseconds or nanoseconds for short range radar or much longer times for radio astronomy, like a few minutes for a pulse to return from asteroids and plan ...[text shortened]... s like Klystrons and Magnetrons and reverse magnetrons and such, not exactly esoteric phenomena.

I skim read the article. The theory group seems to have developed a model of how it works. The lazy hack didn't do enough background reading. Gunn diodes have been around since the 1960's, are used in RADAR, and here is the Wikipedia page:

https://en.wikipedia.org/wiki/Gunn_diode