Wireless power receiving apparatus

An impedance control circuit employed in a wireless power receiving apparatus that receives an electric power signal including any one from among an electric field component, a magnetic field component, and an electromagnetic field component transmitted from a wireless power supply apparatus, and arranged between a reception antenna arranged to receive the electric power signal and a load, the impedance control circuit comprising:

• a third switch arranged between one end of the reception antenna and one end of the load;
• an impedance element arranged between said one end of the reception antenna and an other end of the reception antenna;
• and
• a switch control circuit that switches on and off the third switch at a frequency of the electric power signal,
• wherein the switch control circuit is structured to change a ratio of an on time of the third switch with respect to a period of the electric power signal.

An impedance control circuit employed in a wireless power receiving apparatus that receives an electric power signal including any one from among an electric field component, a magnetic field component, and an electromagnetic field component transmitted from a wireless power supply apparatus, and arranged between a reception antenna arranged to receive the electric power signal and a load, the impedance control circuit comprising:

• a first input line connected to one end of the reception antenna;
• a second input line connected to an other end of the reception antenna;
• a first output line connected to one end of the load;
• a second output line connected to an other end of the load;
• an H-bridge circuit comprising a first switch arranged between the first input line and the first output line, a second switch arranged between the second input line and the first output line, a third switch arranged between the first input line and the second output line, and a fourth switch arranged between the second input line and the second output line;
• and
• a switch control circuit that switches on and off the first switch through the fourth switch of the H-bridge circuit,
• wherein the switch control circuit is structured to change a phase of a switching operation for each of the first switch through the fourth switch, wherein the switch control circuit is structured to sequentially switch its state in synchronization with the electric power signal between:
• a first state in which the first switch and the fourth switch are turned on and the second switch and the third switch are turned off;
• a second state in which (i) the first switch and the second switch are turned on and the third switch and the fourth switch are turned off, or otherwise (ii) the first switch and the second switch are turned off and the third switch and the fourth switch are turned on;
• a third state in which the second switch and the third switch are turned on and the first switch and the fourth switch are turned off;
• and
• a fourth state in which (i) the first switch and the second switch are turned on and the third switch and the fourth switch are turned off, or otherwise (ii) the first switch and the second switch are turned off and the third switch and the fourth switch are turned on;
• and wherein the switch control circuit is further structured to change a length of each of the first state through the fourth state,
• and wherein the switch control circuit is further structured to change a transition phase of a cycle of the first state through the fourth state.