simple way to add harmonics to a fundamental signal

[mbartkow at ET.PUT.Poznan.PL]

> 2x, 4x frequency may be obtained by full wave rectifying (proper dc offset
> after each stage).  Input a tri wave, or sine. The result will still
> have some fundamental left, but in a mix with the fundamental, this is ok.
> 
> 3x is harder to obtain. You could try to feed a sine into a Tchebycheff
> polynome function.  3x would require a 3rd-order polynome.
> 
> The question is how to get the x**3, x**2 functions needed.
> Multipliers are expensive, that's why I thought about a nonlinear diode network.

Did you consider x**n=exp(n*log(x)) ?

log(x) might be obtained once and used to all x**n terms required.
I don't think very precise log/exp converters are needed here, so it's only
one tranny and one opamp per x**n term + one pair for log(x).

regards,

mb.


--

Maciej Bartkowiak
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