| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-frequency power supply device capable of outputting a high-frequency power which is close to performance limit of the device even under such condition as impedance with a load is not matched.SOLUTION: As a low pass filter 15 which removes high frequency component from an output of a power amplifier 12 that amplifies high frequency signal, a first circuit configuration in which only one λ/4 type T type low pass filter works effectively and a second circuit configuration in which two λ/4 type &pgr; type low pass filter in cascade connection work effectively are switched over using a switch. Based on a reflection coefficient at an output end of the high-frequency power supply device 1, it is determined whether an impedance viewed from the high-frequency power supply device toward a load side is inductive or capacitive. According to the determination result, the switch is controlled so that an impedance when viewed from the power amplifier 12 toward the load side is appeared to be inductive at always. |
