Hitachi Maxell Ltd developed a wireless power transmission system that realizes bidirectional data transmission by, for example, superimposing communication signals on electricity being transmitted.
The system was exhibited at Techno-Frontier 2013, which runs from July 17 to 19, 2013.
The wireless power transmission of the system is based on an electromagnetic induction method. Some conventional wireless power transmission systems have a data transmission function that sends data on battery status, etc from a power-receiving device to a power-sending device.
"Ours is the first system capable of sending data from a power-sending device to a power-receiving device," Hitachi Maxell said.
The bidirectional data transmission technology of the new system is similar to the technology used for data transmission between an RFID reader/writer and a wireless tag. Specifically, to transmit data from a power-sending device to a power-receiving device, ASK (amplitude shift keying) is used. And, to send data from a power-receiving device to a power-sending device, backscattering modulation is used. The data transmission speed of the system is 2 kbits per second at this point.
Hitachi Maxell is currently developing a lithium-ion (Li-ion) rechargeable battery having a function to wirelessly receive electricity. And the latest technology is targeted at the battery. At the exhibition, the company had a demonstration of wirelessly transmitting power to a 8.5mm-diameter Li-ion battery equipped with a power-receiving antenna and a communication circuit.