diode

[greg123]

Hey,<p>Can a diode provide amplification??

[billdar]

no, but it can provide dynamic attenuation...

[russlk]

A tunnel diode can amplify and operates at very high frequencies. It was a breakthru device 30 years ago but does not have much application today.

[billdar]

I though tunnel diodes were similar to zenors. plus, how do you get amplification from a 2 lead device?

[Ron H]

Check out this site:
http://www.fnrf.science.cmu.ac.th/theor ... %2011.html<p>Ron

[Bernius1]

WITH TWO DIODES AND A COUPLE OF CAPACITORS, YOU CAN MAKE A VOLTAGE DOUBLER. THE ONLY APPLICATION
I WOULD SEE THIS AS USEFUL WOULD BE AS A CLASS-C
AMLIFIER, BOOSTING VOLTAGE ON THE OUTPUT SIDE OF
A FREQ.MODULATED RF AMP. BUT I DON'T THIK YOU'D
GET POWER AMPLIFICATION, JUST VOLTAGE BOOST

[Ron H]

Voltage doublers are rectifiers. The output is a DC voltage. I've never seen one used on RF. It takes several volts of AC for a voltage doubler to be effective, because two diode drops (about 1.4v, in the case of silicon) are lost in the doubling process. So, if your input is a waveform that is 10 volts peak-to-peak, you will get about 8.6 volts DC. Voltage doubling "doubles" the peak voltage. It actually yields a DC voltage that is equal to the peak-to-peak input voltage, minus two diode drops. It works best with a 50% duty cycle waveform.<p>Ron

[bobsRAC]

Tunnel diodes have a operating region in which the device exhibits a negative resistance.<p>The first radio transmitters were operated without the use of a three terminal device. The US military even used 1 MegaWatt transmitters before the invention of the vacuum tube. This was made possible by the negative resistance charactersistics of a plasma arc.

[Dimbulb]

When photons react on a pin diode they are waves, lets call them an AC signal. You can adjust the threshold of a diode so that it approaches zero by adding enough DC to decrease the barrier of the junction. In a composite ac(signal)/dc you could concider it amplification. At a given input sometimes very very small signals are passed to a three junction semiconductor where amplification is deemed as an attribute of this component even though it works as an integral part in this configuration.
a cesium diode is sometimes thought of as a battery. The nature of the diode is sometimes expressed in terms of which setting it is employed but a PN junction is still a PN junction. Where you take the diode is up to you.

[Edd]

Ahh yes ...the Esaki or tunnel diode.Seems like my dealings with the units was waaay back in 1968 when I had 5 eng samples of the 1N1312-16 series of G.E. units. Not that I used them in an amplifier config, but instead constructed a CW transmitter unit for utilization on the 10 meter Ham band for a hidden transmitter hunt. The resultant unit had but a mere 1/2 in board footprint including the loading coil for the
units 1 ft dangling wire antenna element , with an equal amount being required for its mercury battery- power cell. This could be bested somewhat with todays chip resistors,etc.
The only critical thing was trimming in the the supply voltage to the circuits moderately touchy tunneling threshold.
It was quite amusing on the hunts field day when the usual brick xmitter was found by hunters in a moderately secluded hiding place on top of a large lower limb of a big oak
tree....totally devoid of its battery,
with its connector dangling. However, the received signal was still booming in from the totally invisible aforementioned unit, on a much higher limb, lashed on with light monofilament.
At hunts end there were ~ 80 participants scrutinizing this new mystery unit. All trying to find its hidden transistor in the readily visible circuitry or squirrelled away inside some component....despite the observation that none of its individual integral components exceeded a 2 lead count. Plus.....in '68 a "micro-mini" xstr was the pancaked version of the TO-18 housing. So 80 participants and 100% all neophytes to this new technological device......mechanically/visually with a casing like a smaaal 1/16 rivet with its two leads protruding from it axially.
For anyone who wants to see many utilizations of the device they can refer to that G.E. manual I used,
site location is:
http://martingriffith.users.btopenworld.com/TDOSC.HTM
73's de Edd
[email protected] (Interstellar~~~~Warp~~~~~Speed)
[email protected] (Firewalled-Spam*Cookies*Crumbs)

[Dimbulb]

a schematic of a few jfets back to back has negative resistance like tunnel curve.
It is used as the heart of a grid dip meter.<p>http://www4.tpgi.com.au/users/ldbutler/ ... pMeter.htm

[bwts]

Isnt a transistor two diodes back to back? Arent they used for amplifying? mmmmmmmm!

[Edd]

Did we interpret that long Hmmmmmmm to be surmising the configuration of two isolated/ separate diodes ? They would be lacking the commonality of their PN junction medium. A comical analogy might be having two buckets filled with water and having two ropes each with a knot on the end dangling down into its
individual bucket , then jiggle one and watch the ensuing ripples and then go over to the other bucket and check for ripples…........what ripples ? ……now if the ropes
were in the same bucket………

[bwts]

Now eyem confused

[Bernius1]

Let's get more surreallistic. You can pump water
uphill,if you have a downward slope, and a swing
check valve at the bottom. Like the doubler raising peak voltage. Now, if THAT voltage fed the base of a 2N3055 (like in a power supply),
(with the required cap's in circuit),wouldn't that raise the potential of the remainder of the circuit???
...Picard out...