A proposal of data transmission in parallel line fed wireless power transfer

This paper proposes a data transmission for parallel line fed wireless power transfer system. We focus on power receiver-to-source transmission link and employ the load modulation as a modulation scheme. To transmit data back to the power source from receiver, the power receiver periodically switches its load impedance to modulate the electric current, which can be observed at the source using envelope detection. The load modulation generally has a trade-off between modulation index and power transfer efficiency. Numerical analysis showed that, the system is able to achieve sufficiently a high modulation index while maintaining a high power transfer efficiency, if appropriate switching values for load impedance are employed. This result clarifies feasibility of the proposed load modulation.