ABSTRACT
The family of pseudomorphic HEMTs based on GaAs substrate devides into two main classes of transistors: the pseudomorphic single-heterojunction HEMT (SH-PHEMT) and the pseudomorphic double-heterojunction HEMT (DH-PHEMT). In this paper, the respective advantages and drawbacks of these two different device concepts are discussed in view of the intended frequency range and with respect to the question if a small or large signal amplifier application is envisaged.
