Modified determinations of stability criteria for accurate designing the linear two-port amplifiers

An important consideration in designing linear two-port amplifiers is ensuring that the amplifiers are stable. The conventional treatments are graphic methods where the input/output stability circles are first given to assure the unconditionally stable area in the Smith chart. However, it is difficult to process the input-match and output-match simultaneously, since the source and load plane are made dependent on each other. Plots for working out the available matching area of linear two-ports have been presented here. From the study of the interaction among the input/output stability and the conjugate match conditions, the modified stability circles which are designated as matching circles are analytically developed. The available matching area is specified by using the modified determinations of the stability criteria