An ultrasonic through-metal-wall power transfer system with regulated DC output

This paper presents a novel and efficient system capable of transmitting medium-power electric energy through a solid metal wall and generating a regulated direct current (DC) output. The electric power is transmitted using radio frequency (RF) ultrasound without physical penetration. An RF alternating current to direct current converter with input impedance matching is used to convert the transmitted RF signal to a DC output, which is directly suitable as a power supply for electronic devices. The system is constructed from commercial off-the-shelf components, and a computer-controlled measurement method is designed to test the effectiveness of the full system. The measurement results show that the system is able to transfer power through a 40-mm-thick stainless steel plate and generate 5-V, 15.7-W regulated DC output power with an overall power transfer efficiency of 27.7%. In addition, the effectiveness of the system is successfully demonstrated by powering ARM® evaluation boards with liquid-crystal display panels. A discussion of potential enhancements that could be made to improve the transfer capability and efficiency of the system is also presented. This system could be applied to improve safety and preserve structural integrity in many industrial and military applications, such as submarines, space crafts, planes, nuclear storage facilities, etc.