"Clifton T. Sharp Jr." wrote in message
...

I'm not sure I was clear on my question. The only nonlinearity I want in
my detector diode is the noncontinuous function

| Vin when Vin = 0.000000 micronanofemtoattovolts
Vout = |
| 0 when Vin 0.000000 micronanofemtoattovolts

...while the author seems to be saying that the nonlinearity which exists
just above the barrier voltage is essential to detection. He does say,

"The slope must be steeper (or shallower) at higher voltages and
shallower (or steeper) at lower voltages than at the quiescent
operating point."

Am I missing the contradiction? Say you have a quiescent operating point of
0V. An ideal diode would have an infinately high slope above that point and
a 0 slope below that point. Or vice-versa. That seems to fit the given
statement.

Real world diodes have differing ideal q-points and variable slopes. And
most of the other articles seem to be aimed at getting the most out of such
diodes.


Given my perfect diode and (let's say) a 0.25V peak signal, I contend
that my output envelope will be an exact reproduction of the input
envelope; but (see his graph #2) his required nonlinearity will seriously
distort the output envelope.

I think your perfect diode analysis is correct. I think the only
nonlinearity the author requires is around a q-point. I don't get the
impression the author requires a diode to have a variable slope
characteristic at other voltages.


He seems to be saying that without that, you can't demodulate the signal.
I assert that without that, I demodulated it better than he did.

The author's last revision was on 07/2/2003, so he must still have an
interest. I suppose you could send him an e-mail. The address is the first
item in article #1.

--
Frank Dresser