Clamped-mode resonant converter implementation of an RF power amplifier

The authors improve on the energy efficiency of the power amplifier presented in an earlier paper, using soft switching techniques. A clamped-mode resonant converter is proposed to implement a RF power amplifier. They analyze the operation of the converter with a parallel equivalent load. Then, they design the filter that couples the power to the antenna using a procedure that was previously developed by the authors. Finally an experimental prototype is implemented to generate a carrier signal of 300 kHz, with 300 W on a 50 Ω load. Operation with constant and variable loads is tested, confirming that the resonance condition is preserved even when the load varies in a wide range