Hmmm...I know that there are other ways to generate sampling pulses in
things like (ultra) fast sampling scopes. I suspect that similar
techniques can be used for fast edges. What little I know about that
area I can't really say much about.

After my SRD posting, I reviewed a little more in the Inventions of
Opportunity book. The late '50's fast sampling scope article
mentioned that the HP Labs researcher who saw the diode recovery
phenomenon went on to gain understanding about the mechanism involved,
and presented a paper about it at one of the semiconductor
conferences. A couple articles later in the book there's one devoted
to SRDs. They show a *20 frequency multiplier in one stage using a
SRD. Net efficiency can be pretty good, with the proper design. Just
don't want to be actually dissipating the energy that's in all the
other harmonics.

Cheers,
Tom



Roy Lewallen wrote in message ...
Tom Bruhns wrote:
. . .
. . . Seems like step
recovery diodes are not in as great favor as they once were, since
there are generally better ways to generate higher order harmonics.
. . .

Getting a bit off-topic here, but as of a few years ago, we were using
step recovery diodes to generate the step in high speed TDR systems, and
to generate the strobe for the sampling gate in high speed sampling
scopes. Rise times were on the order of 7 - 15 ps (bandwidth up to 50
GHz or so), limited primarily by circuitry external to the diodes. SRDs
replaced tunnel diodes in earlier generations of instruments. I've been
out of touch with that class of instruments for a few years now -- do
you know if something has replaced the SRD for generating fast steps, or
just for harmonic generation?

Roy Lewallen, W7EL