gwhite wrote:
Kevin Aylward wrote:

gwhite wrote:

Its that simple. I clearly stated that it was *not* a
definition.

"Linearity can more easily be expressed as: a(f(t)) = f(at)" -- Kevin
Aylward

I think someone is posting under your name. A nasty bit of business
that is.

Linearity can be expressed by this, however, it is not a necessary
condition. I never claimed that it was a complete definition.


It was simply trying to illustrate the concept of constant
gain. You expanding on some trivial minor point to avoid answering
the main issue, to wit, you have failed to disprove my claim on your
class A amplifier.

Class A works just fine in multipliers/modulators

Never said it didn't. However, the class A bit does not account for how
they multiply.

-- "non-linearity"
of circuit elements is not required.

Ho humm. Now for the example that does indeed use non-linearity.

Maybe you can analyze the old
MC1496. That would be enlightening to you.

Yep.

Not at all. You are an completly mistaken. It is abundantly clear that
you don't know the first thing about analogue circuit design. It is
truly amazing and unbelievable that you can be so wrong and not be aware
of it. You are an incompetent.

The MC1496 is a double balanced modulator based on the Gilbert cell
transconductance multiplier. The Gilbert cell multiplier relies on the
exponential relation of collector current to base emitter voltage. That
is, its transconcutane is a function of its emitter current. Its well
understood by all those knowledgeable in the field. to wit:

I = Io.exp(V/Vt)

transconductance gm = dI/dv = d(Io.exp(V/Vt))/dv

gm = Io/Vt.exp(V/Vt)) = Ie/Vt

That is, the gm is a function of Ie.

Since:

Iout = gm.Vin

we have

Iout = Ie/Vt.Vin

That is, Iout is a product of, Ie and Vin. Making Ie a function of
another voltage results in the multiplication of two voltages, i.e. a
modulator.

How you can make such daft claims and not be embarrassed shows greate
stamina, I must say.


But more important and
more simple (it will save you loads of time), just apply *the*
linearity test for

h(t)
x(t) - y(t).

You still haveny cottoned on the fact that you wily nilly apply
definitions you no hope of understanding.


The notion that y=x^2 is a non-linear equation is
universally accepted by anyone who has done even the slightest bit of
theory on basic algebraic equations. It does not require any
qualification in the slightest.

No ****, by why are you rambling on and on about it?

Because you don't understand it.


Show me one, and I mean just one, that
declares y=x^2 a linear equation.

That is clever -- you want me to "declare" something is true that I've
made no reference to.

You have. See above. You claimed the Gilbert cell did not rely on
non-linearity. Jesus wept again. Your so out to lunch on this that its
unreal. Look, own up your just trolling aren't you.

You are quite the inventor. Face it: you had
an incorrect notion about linearity.

Dream on. You have been soundly proven wrong, and why you are wrong.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.