The Research Of High-efficiency Class-F And Inverse Class-F Power Amplifiers

As one of the core components in radio transmitters of modern wirelesscommunication systems， the performances of power amplifiers directly affect thequality of the systems. And the efficiency of power amplifiers directly determinesthe efficiency of the systems, as it will lead to low power consumption. Hence howto effectively improve the efficiency turns into an important task of poweramplifiers design. The class-F and inverse class-F power amplifiers have drawn themost attention from engineers because of the simple structure and their capabilityof providing excellent theoretical efficiency, which is100%. High-efficiency classF and inverse class F power amplifiers based on harmonic control circuit andLDMOSFET, which is widely used on communication, are designed and researchedin this paper.The theory of RF power amplifiers is studied and researched firstly, and thenthe basic reason of class F and inverse class F power amplifiers to achieve highefficiency are analyzed from the basic principles. Finally, high efficiency class Fand inverse class F power amplifiers is simulation analyzed by using microwavesimulation software. Based on the lager signal modal of the transistor, load pulltechnology and harmonic balance technology,4W high efficiency class-F andinverse class-F power amplifiers with harmonic control circuit are designedrespectively. In order to validate the results of theoretical analysis and simulation,the samples of4W high efficiency F class and inverse F class power amplifierswith harmonic control circuit are tested. When input power is20dBm, the outputpower of inverse class-F amplifier measured is36.33dBm as class F amplifier is36.17dBm. The maximum PAE of inverse class-F amplifier measured is71%, whichis slightly higher than class F amplifier (70%). All specifications satisfy the designrequirements, and consisted with the simulation results.