impedance after the coupling system, which is the combination
of rectifier, DC/DC converter and load. By designing the
rectifier and DC/DC converter accordingly, the impedance
requirement of the coupling system is fulfilled. A 13.56 MHz
wireless power transfer system is demonstrated in this paper.
When transmitting 50 watts power, it can achieve an efficiency
of 73% for a resistive load and an efficiency of 66% for
charging batteries or supercapacitors.