This is a good learning experience for lots of us out here. Any chance of
scanning the printed material and posting , say on a.b.s.e?

On 13 Apr 2004 10:44:19 -0700, (Tom Bruhns) wrote:

Hi Harold,

Nice of John to make that offer!

As for background and theory, I'll make copies of an artcile or two to
send you, about the discovery of the effect and the optimization of
diode structure to enhance it. I suppose that the effect you're
seeing with the Schottkys is almost entirely capacitive stored charge,
and that won't "sweep out" of the diode with the sharp step you get
with a step-recovery diode. The articles I'll send have info about
efficiency, which can be surprisingly high considering the high order
of multiplication.

Cheers,
Tom

"Harold E. Johnson" wrote in message news:3QBec.21137$_K3.55643@attbi_s53...
If you do use diodes for higher-order harmonic generation, and not
just a simple full-wave-rectifier type frequency doubler, I suppose
you want something of the nature of a step recovery diode. That
implies minority carrier stored charge in the diode, and that would
preclude using a Schottky diode (which would work great in the
full-wave-rectifier type doubler). If you get into actually wanting
to generate harmonic combs out to microwave frequencies, it's probably
worthwhile looking for diodes actually characterized for step recovery
service. But I really think that's way beyond what you are trying to
accomplish right now.

My turn to learn something here. Tom, would you elaborate a bit on the above
please? I know SRD's are comb generators out to visible light, but they're
also 50 percent hard to find and 50 percent magic. I've been using
Schottky's for X16 multipliers to 2 GHz, am I doing something wrong? (I keep
promising myself that I'm gonna substitute an MMIC for that one day, I DID
find the "Filter Gain" in the line length from generator to filter), THAT
was both impressive AND helpful. If I go with the MMIC, any preference of
Silicon over GaAs?

Regards

W4ZCB

Tony (remove the "_" to reply by email)