US Patent 9362783 Wireless power transmission apparatus using ultrasound

Provided is a wireless power transmission apparatus. The apparatus includes an ultrasound transmitter generating an ultrasound signal in response to an external source voltage and transmitting the generated ultrasound signal to a medium layer and an ultrasound receiver receiving the ultrasound signal through the medium layer and converting the received ultrasound signal into a driving voltage. The ultrasound transmitter and receiver are manufactured to control impedance values thereof to be matched with each other and a distance between the ultrasound transmitter and receiver is controlled according to predetermined distance conditions.