[time-nuts] Norton amplifiers
Jeffrey Pawlan
pawlan at runbox.com
Mon Jan 13 17:27:58 UTC 2020
Many years ago I did a study of Norton amplifiers and optimized for IP3
using non-linear circuit simulation tools. I published a two part
article in RF Design Magazine which covered the amplifier itself as well
as the non-linear model for the BJT. My use for the Norton amplifier did
not require high isolation so I spent little tile on that aspect. I am
friends with the co-inventor of the original and the author of the
subsequent patents. His name is Allen Podell. The webpage you included
speculated that the reverse isolation degradation at high frequencies
was owing to the layout or the transformer. Although those are
contributors, the simulation showed high frequencies had poorer s12 so
it is expected.
If high isolation is what you need, then as written on this list, there
are ICs which can provide this much better than a single stage
amplifier. They do suffer from more residual noise however.
Jeffrey Pawlan
More information about the Time-nuts_lists.febo.com
mailing list