US Patent 10105172 Radiofrequency amplifier impedance optimization

The present disclosure is directed to an electrosurgical generator including a resonant inverter having an H-bridge and a tank. The generator also includes a pulse width modulation (PWM) controller configured to output PWM timing signals to the H-bridge. A switch is configured to select a modality from among a plurality of modalities and the PWM controller adjusts a frequency of the PWM timing signals based on the selected modality.