| 摘要 |
An impedance matching device is installed between a transmitter circuit and a transmitting antenna in a wireless power transmission system based on an electromagnetic resonant coupling system. A reflection coefficient calculation unit calculates a value equivalent to the absolute value of the reflection coefficient on the basis of the voltage of a traveling wave and the voltage of a reflected wave extracted by a traveling wave and reflected wave extraction unit. A phase determination unit determines whether the voltage of the traveling wave and the voltage of the reflected wave are close to the same phase or close to the reverse phase. A matching circuit selection unit, which, on the basis of the value equivalent to the absolute value of the reflection coefficient and the result of the phase determination unit, electrically connects either a first form matching circuit, a second form matching circuit, or a through circuit, in which a matching circuit is not inserted, between the transmitter circuit and the transmitting antenna. A storage unit selection unit selects either a first storage unit or a second storage unit on the basis of the phase determination result. A control value output unit applies the control value to either the first form or the second form matching circuit as selected by the matching circuit selection unit. |
