Efficient modeling methods on GaAs MESFETs for Ku- and Ka-band power amplifiers

Nowadays GaAs MESFETs dominate in modern MIC/MMIC applications such as switches, PA, LNA, oscillator, etc. Therefore, reliable modeling methodologies and accurate device models of GaAs MESFETs are extremely crucial and in great demand. In this paper, both small signal and large signal modeling methods of GaAs MESFETs will be addressed. Firstly, a GaAs MESFET distributed model based on the accurate EM simulation and optimization method will be presented. For the large-signal modeling of GaAs MESFETs, an improved drain current expressions and a novel gate terminal charge model of gate capacitors will be illustrated. For complete model evaluation, the modeling methods will be extended to design Ku- and Ka-band power amplifiers and good agreement between simulation and measurement will be demonstrated.