[sdiy] Block based design was: Favourite VCO designs

[David G. Dixon]

> If you're in the Laplace domain, the Fourier domain is just a substitution
> away:
> 
> if H(s) is the Laplace transform, then
> 
> plug in s = jw, where w is a radial frequency, then bam, you get the
> Fourier transform. ;)
> 
> The Laplace transform can be thought of as an extension of the Fourier
> transform from the imaginary axis to the complex plane.

Yeah, I know that now because I taught myself, first for packed bed dynamics
(early career research), and then for electronic filter analysis (current
hobby).  They just didn't teach us that as undergrads.

It also bears noting that, in fact, s is itself a complex number, s = c + jw
(where c is supposed to be sigma and w is supposed to be omega).  This
little tidbit really makes filter analysis much easier.