| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-frequency power supply device that makes an effective power of a load constant.SOLUTION: From a (t) time point when outputting of a high-frequency power is started, a SWEEP mode for greatly changing a frequency is started, and a voltage standing wave ratio (a VSWR value) that is a ratio of an FWD value and an REF value is calculated. When the VSWR value becomes equal to or less than a VSWR threshold that is preliminarily defined (when a reflection wave is reduced to a predetermined level), an ADJUST mode for finely changing the frequency depending on the VSWR value is started (t). In addition, with respect to an REF value proportion calculated from the REF value and the FWD value, an REF value proportion difference that is a difference between previous and this-time REF value proportions is calculated. When a state that the REF value proportion difference is equal to or less than an REF value proportion difference threshold that is preliminarily defined continues for a predetermined time period (from tto t), it is determined that matching is saturated by frequency control, and power corresponding to a reflection wave power (W) is added to a progressive wave power (W) to perform effective power constant control for according an effective power to a target output. |
