| 摘要 |
When treating items with high-frequency electric power there is a need for making a correct impedance matching can be made between a generator and a tool holding the item to be treated, and there is a need to avoid the formation of standing waves in transmission lines, etc.. In addition there is a need to be able to treat items having a dimension which is comparable with the wave length at the frequency used, and to be able to exactly measure the power transmitted to the treated item. This object is attained by means of a method which comprises tuning of a circuit to resonance and adjustment of an impedance transforming ratio to correct impedance matching, as well as correction of said adjustments during the treatment of the item. For carrying out the method an apparatus is provided which comprises at least two variable impedances as well as means for detecting deviation from resonance and from correct impedance matching. The two variable impedances are preferably a continuously variable capacitor and a continuously variable coil, and the detection is performed by measuring of the standing wave ratio on the transmission line. |
