Variable-Voltage Class-E Power Amplifiers

The class-E power amplifier is widely used due to its high efficiency, resulting from switching at zero voltage and zero slope of the switch voltage. In this paper, we extend general analytical solutions for the class-E power amplifier to the ideal single-ended variable-voltage class-E (class-E_VV) power amplifier that switches at zero slope but not necessarily at zero voltage. The theory is verified by simulations and measurements, and show that the peak switch voltage of class-E_VV power amplifier is lower (up to ap 30% ) than in the conventional class-E power amplifier; which can be utilized to obtain e.g. higher output power (up to ap 200% more) with lower power-added efficiency (maximum ap 20% less) from technologies with low-breakdown voltages.