Patent ID: 10291198

Abstract:
A matching device includes: a directional coupler that detects a traveling wave and a reflected wave; a matching circuit that has a first variable capacitance capacitor, a second variable capacitance capacitor and an inductance; and a control unit that calculates a reflection coefficient based on the traveling wave and the reflected wave and controls a capacitance value VC1 of the first variable capacitance capacitor and a capacitance value VC2 of the second variable capacitance capacitor. The control unit changes VC2 such that VC2 moves toward a circle drawn by the trajectory of the reflection coefficient passing through a matching point on a Smith chart, fine-tunes VC1 on the basis of a predicted intersection point with the circle, and when the distance between the calculated reflection coefficient and the circle becomes a predetermined value or less, changes VC1 such that the calculated reflection coefficient approaches zero, and fine-tunes VC2.