| With the development of wireless technology, spectrum resource become scarce, in order to improve the bandwidth efficiency, modern wireless communication systems employ very complex modulation skill, these kinds of modulation skills make signal with high PAR, to ensure the communication quality power amplifier has to be made with high linearity. However, with the miniaturization of electronic devices and improvement of energy-efficient performance, system put forward higher requirements for the efficiency of the power amplifier. Power amplifier serves as the main power consuming modules in the RF transceivers, improving power amplifier's efficiency can effectively save energy. Therefore, researching for a power amplifier with high efficiency and high linearity can save energy under the condition of ensuring the communication quality becomes significant.Outphasing power amplifier that can improve power amplifier's efficiency and linearity has obvious technical advantages and high research value. This paper focuses on the study of high-efficiency power amplifiers in outphasing system, discussing the reason that power amplifier in the outphasing system with non-isolated combiner has a time-varying load, aiming at the reason, several classes of the common power amplifier are compared to choose the most fitted one for the outphasing system. To minimize the effect that power transistor's parasitic parameters on the efficiency of power amplifier, harmonically tuned class-F power amplifier is employed, the method of sourcepull-loadpull is described, impact of source impedance on the efficiency is analyzed, simulation and test of the class-F power amplifier is completed. Harmonically tuned class-F power amplifier is applied in the outphasing system, system simulation and test is done. |
PDF Full Text Request