Abstract
The considerable explosion these last three years of power MMICs based on the pseudormorphic GaInAs channel (PM HEMT) has crown the leader position of this device for power applications. Initially considered to be essentially promised to ultra low noise amplification it has gained record drain current and cutt-off frequencies together with remarkable progress in breakdown voltage. Owing to its maturity and reliabily it now permits realization of nearly 1 watt modules at Q and even V bands but it is also progressively surpassing MESFETs and able to compete with HBTs in the microwave low frequency range, for example in the mobile communications market. The question to be asked now is, first, what can be the ultimate expansion of the pseudomorphic HEMT technology and, second, among the new emerging technologies what can be expected as future power FETs developments.