MODIFIED DETERMINATIONS OF STABILITY-CRITERIA FOR ACCURATE DESIGNING THE LINEAR 2-PORT AMPLIFIERS

An important consideration in designing linear two-port amplifiers is ensuring that the amplifiers are stable. The conventional treatments a re graphic methods where the input/output stability circles are first given to assure the unconditionally stable area in the Smith chart. Ho wever, it is difficult to process the input-match and output-match sim ultaneously, since the source and load plane are made dependent on eac h other. Plots for working out the available matching area of linear t wo-ports have been presented here. From the study of the interaction a mong the input/output stability and the conjugate match conditions, th e modified stability circles which are designated as matching circles are analytically developed. The available matching area is specified b y using the modified determinations of the stability criteria.