| 摘要 |
<P>PROBLEM TO BE SOLVED: To resolve a problem that when reducing a direct-current power source voltage Vdc in order to expand an area from which a predetermined traveling wave electric power can be outputted, an amplification element is likely to cause a self-oscillation, then, controlling a high frequency amplification portion 23 becomes in an unstable state. <P>SOLUTION: A direct-current electric power output portion 10, which supplies a direct-current electric power to a high frequency electric power output portion 20, includes an output voltage setting portion 11, a direct-current power source control portion 12, a direct-current power source 13, a direct-current detection portion 14, a reflection coefficient calculation portion 15, a loss calculation portion 16, a target of minimum loss setting portion 17, and a voltage correction portion 18. A relation between a reflection coefficient and minimum loss is memorized in the target of minimum loss setting portion 17, the minimum loss correspondent to the reflection coefficient calculated by the reflection coefficient calculation portion 15 is to be the target of minimum loss Tloss. Moreover, when a loss Ploss calculated by the loss calculation portion 16 is lower than the target of minimum loss Tloss, the voltage correction portion 18 corrects an output voltage setting value Vset set by the output voltage setting portion 11 to be larger. <P>COPYRIGHT: (C)2010,JPO&INPIT |
