Gain-bandwidth limitations of microwave transistor

Abstract

This work enables one to obtain the potential gain (G(T)) characteristics with the associated source (Z(S)) and load (Z(L)) termination functions, depending upon the input mismatching (V-i), noise (F), and the device operation parameters, which are the configuration type (CT), bias conditions (V-DS, I-DS), and operation frequency (f). All these functions can straightforwardly provide the following main properties of the device for use in the design of microwave amplifiers with optimum performance: the extremum gain functions (G(T) (max), G(T) (min)) and their associated Z(S), Z(L) terminations for the V-i and F couple and the CT, V-DS, I-DS, and f operation parameters of the device point by point; all the compatible performance (F, voltage-standing wave ratio Vi, G,) triplets within the physical limits of the device, which are F greater than or equal to F-min, V-i greater than or equal to 1, G(T) (min) less than or equal to G(T) less than or equal to G(T) (max), together with their Z(S), Z(L) termination functions; and the potential operation frequency bandwidth for a selected performance (F, V-i, G(T)) triplet. The selected performance triplet and termination functions can be realized together with their potential operation bandwidth using the novel amplifier design techniques. Many examples are presented for the potential gain characteristics of the chosen low-noise or ordinary types of transistor. (C) 2002 Wiley Periodicals, Inc.