The efficiency of class-F and inverse class-F amplifiers

The efficiency of class-F and inverse class-F amplifiers are studied using measurements and theories. At high quiescent current, inverse class-F amplifiers show higher efficiency than that of class-F. This phenomenon is experimentally ensured with GaAs pHEMTs and GaAs HBTs. A harmonic balanced simulation also supports this result, and reveals the difference between the classes. An analytic waveform analysis with restricted harmonics explains this dependence on the quiescent currents.