Study Of RF Power Amplifiers Based On SiC MESFET

With the development of wireless communications and microelectronic technologies, modern communication is developing towards adding channel capability, multi-carrier, multi-level, widening the frequency and higher PAR. All these changes make the design of wireless communication equipment more difficulty. As the core of the transmitter, the RF power amplifier accounted for most of the power of the whole system.Therefore, the key to building a radio-frequency system is to improve the efficiency of RF power amplifiers.This thesis does reaearch on the core of the transmitter-high efficiency power amplifiers . First, by comparing the working principles of classic amplifier and switch mode power amplifier, we achieved the conclusion that the switch mode amplifiers had the advantages of higher efficiency; second, the design parameters of class E amplifiers in parallel capacitors and parallel circuits were compared with theoretical discussion, we choosed the latter as the class E amplifier topology.This thesis presents a novel way to design class E amplifier with output shunt capacitor which is composed by the parasitic capacitor of SiC MESFET devices, and using the matching network of the harmonic suppression Stub, which not only achieve the transformation of the resistance, but also have a very good harmonic suppression. By using the multi-objective optimization of system design methods, the performance of circuit is improved greatly. Finally, this thesis complete the class E power amplifier design by using SiC MESFET model of CREE CRF24010, and carried out simulation with ADS.