CONCLUSION
A multiple-transmitter wireless power transfer scheme via coupled magnetic resonance has been analyzed using electrical circuit theory. For the case of two multiple transmit coils, the gain and diversity effect has been presented. The negative
effect of transmitter resonant coupling has been shown theoretically and experimentally. Practical synchronization issues with regard to frequency and phase have been presented for the multiple-transmitter case. Experiments were also conducted to gauge the effect of resonant frequency shifting due to nearby metallic objects. Frequency shifts can be readjusted to the correct frequency by performing capacitance tuning. A practical
synchronization technique has been presented to ensure proper magnetic field combining at the receiver coil. This was done via PLC with appropriate gain and phase tuning. Future work includes intelligent transmit coils that communicate between each other to enhance power efficiency depending on each coils environment. This includes automatic capacitive tuning for incidental resonance shifts for both transmitter and receiver coils and automatic gain and phase tuning for synchronizing reference signals between transmitters.