Power gain sensitivity of active devices†

Abstract

This paper considers the sensitivity of the power gain of a tuned conjugate-matched amplifier to changes in active device parameters, for the general case wherein the active device may be embedded prior to termination. Prediction of the effect of simultaneous spreads in the eight parameters of the active device is based upon a simple expression—here also displayed as a three-dimensional model for case of insight—relating conjugate-matched gain to two device parameters. These parameters are representative of device activity and non-reciprocity, and are separately invariant to common types of embedding. A new basis is proposed for the characterization of spread between two devices, each represented by a point in a three-dimensional space, and leads to a simple description of the effect of device spread upon power gain. The effect on gain spread of common, types of device embedding is discussed and its simple description verified experimentally. A prerequisite to the treatment of batch spread is the realizat...