Re: Tunnel diode rectification

From: Theo Markettos (theom+news_at_chiark.greenend.org.uk)
Date: 03/09/05 

Date: 09 Mar 2005 15:30:54 +0000 (GMT)

Fred Abse <excretatauris@cerebrumconfus.it> wrote:
> On Mon, 07 Mar 2005 16:31:25 +0000, Theo Markettos wrote:
> The valley floor has to be above zero, otherwise the device would contain
> a voltage source.

True, good point.
 
> "Reverse breakdown" isn't really a property of tunnel diodes, they conduct
> in the reverse direction more or less from zero.
>
> Tunnel diodes don't rectify, in the sense that I take you to mean the
> term.

Am I misreading something from the graph at:
http://www.americanmicrosemi.com/tutorials/tunneldiode.htm

which seems to suggest that they're basically like a Zener except the
tunnelling current means they have a lower resistance at low applied
voltages than at medium ones? I suppose the problem is lack of scale on the
left/lower parts of the graph. It does seem to suggest that they're
actually better at conducting in the reverse direction than the forward
direction - is this true? I can't seem to find any datasheets on these
diodes.

My interest is for a crystal radio, where the forward voltage drop of a
silicon, Schottky or germanium diode means you lose a lot of signal, but
power isn't available. I was wondering whether a tunnel diode might be more
efficient? Are there any other types of diode that might do the trick
instead?

Thanks
Theo 

-- 
Theo Markettos                 theo@markettos.org.uk
Clare Hall, Cambridge          atm26@cam.ac.uk
CB3 9AL, UK                    http://www.markettos.org.uk/
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