The Parameter Model And The Design Of RF Amplifier For 4H-SiC MESFETs

SiC is a very promising candidate for high temperature, high power, high frequency, and radiation hardness applications because of its superior properties such as wide band gap, high critical breakdown field, high thermal conductivity and high saturation electron drift velocity. Therefore the microwave power devices-Metal Semiconductor Field Effect Transistors (MESFETs) based on 4H-SiC have received increased attention. The large-signal model and the design of RF power amplifier of 4H-SiC MESFET have been studied in this paper.Based on the material parameters and the device structure of 4H-SiC MESFET, two methods are presented to simulate the large-signal behavior. The first method is the large-signal model based on the high-frequency small-signal physical model and equivalent circuit of 4H-SiC MESFETs. Combining the anylatical model with empirical model, the second method, a CAD oriented 4H-SiC MESFET quais-anylatical parameter model, is presented considering the fundamental operation principle of 4H-SiC MESFETs. Based on the 4H-SiC MESFET quais-anylatical parameter model presented in this paper, a 4H-SiC MESFET RP(Radio Frequency) amplifier is designed with the software ADS.The work of this paper not only provides some basic references for the further nonlinear microwave characteristics and device design for 4H-SiC MESFETs, but also instructs the further CAD oriented large-signal models and the design of RF small-signal and power amplifiers of 4H-SiC MESFETs.