Sjoland - distortion cancellation (after Sandman)

[ihan]

I was searching the net for distortion or error correction techniques and found this technique described by Sjoland after a patent app by Sandman.

Do a google search for: sjoland distortion cancellation

or try this (long) link copied from my browser:

http://books.google.co.uk/books?id=Q...lation&f=false

I've simulated the non-inverting case in pspice and found that it reduced THD20 by approx 20dB.

I wonder if anyone has actually built a power amplifier using this principle. It has the advantage that it could be applied to most voltage feedback amplifiers.

Stability is definitely an intriguing prospect, although I could get it to work with an opa604 enhanced macromodel, with the input of the main amplifier more degenerated (for example 470R emitter resistors, instead of 100R ones).

[kenpeter]

Negative resistance = Oscillator bait
Boosting NFB??? You better have tight control over phase at all frequencies...