Patent attributes
A high-frequency power supply apparatus includes the following elements. A first power supply outputs a first high-frequency voltage with a first fundamental frequency. A second power supply outputs a second high-frequency voltage with a second fundamental frequency lower than the first fundamental frequency. A second matching device is connected between the second power supply and the load. The second matching device generates a timing control signal with a frequency lower than the second fundamental frequency. The first power supply generates a modulation signal by applying a start phase and a frequency shift amount to a modulation fundamental wave signal whose frequency is equal to the second fundamental frequency. The start phase is applied to the modulation fundamental wave signal in accordance with an input timing of the timing control signal. The first power supply performs frequency modulation on the first high-frequency voltage by using the modulation signal.
