AW: square root

[Haible Juergen]

	>A ring modulator (multiplier chip) with identical sine waves at
	>the 2 inputs produces a sine wave at double the frequency.

Almost. It would also have a strong DC component that prevents
the output from going negative.

	>Now I assume it is possible to put a squarer (ie multiplier
with tied
	>inputs) in a feedback loop to give a square rooter... but what
would the
	>output look like? A sine wave at half the frequency? And what
happens
	>with a less simple input, eg a signal consisting of two sine
waves at
	>different frequencies?

The circuit would probably run into its rails as soon as the input
becomes
negative.

JH.