A Novel High Effciency Power Amplifier Concept for GSM Handsets

The demand for ever increasing talking times and reduced weight of modern GSM handsets can only be achieved by a significant reduction of the power consumption of the cellular handset, mostly the power the power amplifier (PA). The constant evelope modulation scheme of the GSM system allows the desing of high efficiency power amplifier, such as switching amplifiers. Among them. them, the Class-E amplifier concept is best suited, because it allows about 80% efficiency, while maintaining an excellent output spectrum and reasonable gain. Another advantage is the possibility to an a-priori design an characterization of the amplifier stage by simulation this fact is demonstrated in this paper, by comparing simulation and measurement results of a 45-MHz Class-E amplifier as a 1:20 frequency scaled model of a 900-MHz GSM power amplifier. The excellent match between theory and measurement allows a good prediction of the final Class-E amplifier characteristics by simulation.