Patent attributes
A high-frequency power supply device includes: a first power supply that supplies first high-frequency power to a load by outputting a first high-frequency voltage having a first fundamental frequency; a second power supply that supplies second high-frequency power to the load by outputting a second high-frequency voltage having a second fundamental frequency lower than the first fundamental frequency; a first matching unit between the first power supply and the load; and a second matching unit between the second power supply and the load. When frequency-modulating the first high-frequency voltage with a modulation signal having a same frequency as the second fundamental frequency to output a modulated wave, the first power supply repeatedly performs search processing of a start phase of the modulation signal and search processing of a frequency shift amount of the modulated wave such that magnitude of a reflection coefficient or magnitude of reflected wave power reduces.
