Multi-mode wireless charging system

A method of providing charging power to a power receiver, the method comprising:

• determining a first frequency for providing power from a first power transmitter to the power receiver via a first wireless field;
• passing a first signal having the first frequency via a first filter circuit, the first signal for generating the first wireless field at the first frequency;
• passing a second signal having a second frequency different from the first frequency via a second filter circuit, the second signal for generating a second wireless field at the second frequency;
• receiving the first signal from the first filter circuit;
• generating the first wireless field based on the first signal via a first coil circuit;
• receiving the second signal from the second filter circuit;
• generating the second wireless field based on the second signal via a second coil circuit;
• matching impedance of the first coil circuit to impedance observed at the first filter circuit;
• and
• matching impedance of the second coil circuit to impedance observed at the second filter circuit.

A power transfer system for providing charging power to a power receiver, the system comprising:

• means for determining a first frequency for providing power from a first power transmitter to the power receiver via a first wireless field;
• means for passing a first signal having the first frequency, the first signal for generating the first wireless field at the first frequency;
• means for passing a second signal having a second frequency different from the first frequency, the second signal for generating a second wireless field at the second frequency;
• means for receiving the first signal from the means for passing the first signal;
• means for generating the first wireless field based on the first signal;
• means for receiving the second signal from the means for passing the second signal;
• means for generating the second wireless field based on the second signal;
• means for matching impedance of the means for generating the first wireless field to impedance observed at the means for passing the first signal;
• and
• means for matching impedance of the means for generating the second wireless field to impedance observed at the means for passing the second signal.