**4. Conclusions**

An improved 4H-SiC MESFET with a partially low doped channel is designed and simulated in this paper to increase the PAE of the device. The results show that the maximum PAE of the PLDC-MESFET is 43.67%, while the PAE of the DR-MESFET is 23.43%; the optimized PAE was increased by 86.38%. A way to design an energy e fficient amplifier is proposed in this paper by balancing the parameters of the device. This ensures that the device has lower energy consumption at the same output power, which has grea<sup>t</sup> significance for RF power amplifier applications.

**Author Contributions:** Project administration, H.J.; writing—original draft preparation, Y.T.; writing—review and editing, T.L., S.Z., Y.L., Y.Y.; Data curation, X.W.; Formal analysis, T.Z.

**Funding:** This work was supported by the National Natural Science Foundation of China (NSFC) under Grant No. 61671343.

**Conflicts of Interest:** The authors declare no conflict of interest.
