Student design - Efficiency Comparison Between Highly Efficient Class-F and Inverse Class-F Power Amplifiers

The purpose of this note is to provide a clear quantitative explanation of the better efficiency and a design guide for optimizing the output power or efficiency of inverse class-F amplifiers (Woo, et. al., 2006). For this purpose, the efficiency equations of the inverse class-F and conventional class-F amplifiers are derived using ideal time-domain waveforms. Then, analytic comparisons are carried out using these equations under the condition that the fundamental output power of both amplifiers are identical, near where maximum power added efficiency (PAE) is produced. The analysis results clearly show why the inverse class-F amplifier has higher efficiency than the class-F amplifier. We have designed and implemented several inverse class-F amplifiers at 1 GHz to confirm these results