Reappraisal of the unconditional stability criteria for active 2-port networks in terms of S parameters

Abstract

The derivation is given of previously published results for the unconditional stability criteria of active 2-port networks, in terms of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</tex> parameters, that are not only simpler than earlier results but symmetrical, i.e.,