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Stacked Diodes ?

ge

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What physically is "Stacked Diodes"? I"m familar with Beam Lead and Mesa diodes. Is stacked diodes two Mesa diodes in series?
 

dick_freebird

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Most likely this just means a series connection
(So1, So2, So3, "Stack of") for voltage handling
or to get an effectively higher forward voltage
before conducting (like on a limiter / input
clamp, maybe you really want a >1.0V input
signal without distortion, a single 0.7V (or lower
if Schottky) would be right out, So2 might
still conduct at crest at high temp, need So3
to stay clean distortion-wise).

They do not need to be co-processed, could
be multiple dice in a module or multiple leaded
parts on a PCB. Those details would be product
specific and articulated in product datasheet
and/or applications "collateral".
 

ge

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Appreciate the response. I'm looking at limiters and sometimes read reference to "stacking". I'm unable to visualize the mechanical construction of "stacking" diodes. A paper on mwrf.com references stacking but does not say what what or how.

I meant series beam lead diodes in my first posting.
--- Updated ---

I think I just found enough information to see where I am heading...
I found a thin paper, "Designing High-Power Limiter Circuits with GaAs PIN Diodes" written by Triquint. The paper does not discuss series connected stacked diodes but does discuss shunt connected stacked di
--- Updated ---

I think I just found enough information to see where I am going...
I found a thin paper, "Designing High-Power Limiter Circuits with GaAs PIN Diodes" written by Triquint. The paper does not discuss series connected stacked diodes but does discuss shunt connected stacked diodes. ( IEEE Paper )
 
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biff44

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back in the day, varactor diodes were used to generate millimeter wave frequencies in frequency multiplier circuits.
to drive them, pretty big voltage swings at lower frequencies were imparted across the diode. voltage swings like 30 V p-p.

The diodes were biased so that they did not conduct too much current, but those big voltage swings limited how much power you could drive them with, AND due to I squared R power loss, a big voltage swing meant heating up the diode.

Some people figured out that you could put TWO varactor diodes in series, halving the voltage swing, and therefore quartering the power loss. but you needed a good thermal resistance path, so an elaborate scheme was devised so that one of the diodes sat on a thermally conductive cube (diamond was used in one company's version), but electrically insulative.

So you ended up with a high power frequency multiplier by using "stacked diodes". I am fairly sure nobody makes such things anymore.
 

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