Patent ID: 8704607
Filing Date: 2014-04-22
Classification: H01J,H02M,H03F,H03K

Abstract:
1. A pulse modulated RF power control method for controlling RF power to be supplied to a load, the RF power being a pulse output which is a RF output outputted intermittently in time wise, the method comprising: an output amplitude control step for controlling amplitude of the pulse output, a duty control step for controlling a duty ratio of the pulse output, wherein, the output amplitude control step performs a constant amplitude control to control an amplitude value of the pulse output so that the amplitude value becomes equal to a set amplitude value, the duty control step performs a constant power control to control the duty ratio of the pulse output so that a power amount determined by the duty ratio becomes equal to a set power value, and the output amplitude control step and the duty control step are operated independently to perform pulse modulation of the RF power, wherein peak forward power is assumed as a control target of the pulse output in the output amplitude control step, average load power is assumed as a control target of the pulse output in the duty control, the output amplitude control step performs the constant amplitude control so that the amplitude value of the peak forward power becomes constant, and the duty control step performs the constant power control so that an average power value of peak load power which is obtained from the peak forward power and peak reflected power determined by the duty ratio, becomes equal to a set power value, thereby controlling the average load power.