Patent ID: 7630220
Filing Date: 2009-12-08
Classification: H02M

Abstract:
1. A high frequency power supply that supplies a high frequency voltage amplified by an amplification unit to a load, comprising: a DC voltage power source unit that generates and outputs a DC voltage, the DC voltage power source unit being capable of changing an output level of the DC voltage to be outputted; a DC voltage detection unit that detects the DC voltage outputted by the DC voltage power source unit; a DC voltage control unit that controls the output level of the DC voltage power source unit such that the DC voltage detected by the DC voltage detection unit becomes equal to a target voltage; an oscillation unit capable of changing an output level of a high frequency voltage signal to be outputted; an amplification unit including a plurality of amplifying elements, to amplify and output the high frequency voltage signal outputted by the oscillation unit utilizing the DC voltage outputted by the DC voltage power source unit as an energy source for the amplification; an output power setting unit that decides an output power value of the high frequency power to be supplied to the load; a power detection unit that is connected to the load and detects the output of the amplification unit in power value; a high frequency signal control unit that controls the output level of the oscillation unit such that die power value detected by the power detection unit becomes equal to the decided output power value; an amplitude detection unit that detects an amplitude of a voltage between amplified-side terminals of the amplifying elements of the amplification unit, or an amplitude of a voltage that is proportional to the amplitude of the voltage between the amplified-side terminals, the amplitude detection unit being provided separately from the power detection unit; and a target voltage decision unit that decides a target value of the DC voltage based on the amplitude of the voltage detected by the amplitude detection unit.