ELECTRODE UNIT, POWER TRANSMITTING DEVICE, POWER RECEIVING DEVICE, AND WIRELESS POWER TRANSMISSION SYSTEM

An electrode unit is used in a power transmitting device or a power receiving device in a wireless power transmission system of an electric field coupling method. The electrode unit includes a first electrode and a second electrode, which are a power transmitting electrode pair or a power receiving electrode pair, and a matching circuit to be connected between a power conversion circuit and the first and second electrodes in the power transmitting device or the power receiving device. The matching circuit includes a first inductor connected to the first electrode, a second inductor connected to the second electrode, and a first capacitor. The first capacitor is connected between a wire between the first electrode and the first inductor and a wire between the second electrode and the second inductor. The first inductor and the second inductor are magnetically coupled together with a negative coupling coefficient.