Patent ID: 7615983

Claim:
A high frequency power device for supplying high frequency power to a load to generate plasma, comprising: a high frequency detector, detecting a forward wave voltage and a reflected wave voltage in an output end of the high frequency power device to output a forward wave signal corresponding to the forward wave voltage and a reflected wave signal corresponding to the reflected wave voltage; a first oscillator, outputting a signal oscillated by a first predetermined frequency as a first oscillating signal; a second oscillator, outputting a signal oscillated by a frequency within a second predetermined frequency band as a second oscillating signal; a phase adjuster, adjusting a phase of the second oscillating signal outputted from the second oscillator; a modulation index adjuster, adjusting a modulation index of the second oscillating signal outputted from the second oscillator; a modulator, outputting a modulated signal obtained by modulating, in frequency, the first oscillating signal by the second oscillating signal whose phase and modulation index are adjusted by the phase adjuster and the modulation index adjuster respectively; and a high frequency output unit, amplifying and outputting the modulated signal outputted from the modulator or a signal obtained by controlling the output level of the modulated signal.