| Abstract: | Wireless power transmission via a sheet medium is a novel physical form of communication that utilizes a surface as a medium to provide both data and power transmission services. To efficiently transmit a relatively large amount of electric power (several watts), we have developed a wireless power transmission system via sheet medium that concentrates electric power on a specific spot by using phase control of multiple inputs. However, to find the optimal phases of the multiple inputs that let the microwave energy converge on a specific spot in the sheet medium, prior knowledge of the device's position and a preliminary experiment measuring the output power are needed. In the field of wireless communication, it is known that the retrodirective array scheme can efficiently transmit power in a self‐phasing manner, which uses pilot signals sent by client devices. In this paper, we apply the retrodirective array scheme to our wireless power transmission system via a sheet medium, and propose a power transmission scheme using the phase‐adjusted power transmission inputs. To confirm the effectiveness of the proposed scheme, we evaluate its performance by computer simulation and real‐world measurement. Both results show that the proposed scheme can achieve retrodirectivity over wireless power transmission via a sheet medium. |
