Designing repeater coils for wireless charging

A method for designing a repeater coil for wireless charging, the method comprising:

• determining target structural and electromagnetic parameters for a multi-coil system in which the repeater coil increases inductive flux linkage between a transmitting wireless charging coil and a receiving wireless charging coil of a mobile device;
• performing electromagnetic simulations to predict performance characteristics for the multi-coil system given different sets of design parameters for the repeater coil permitted by the target structural and electromagnetic parameters for the multi-coil system;
• based on the electromagnetic simulations, determining an initial set of design parameters for the repeater coil that are predicted to produce a target set of performance characteristics for the multi-coil system;
• fabricating the repeater coil according to the initial set of design parameters;
• measuring electromagnetic characteristics of the fabricated repeater coil;
• performing second electromagnetic simulations to predict performance characteristics for the multi-coil system based on the measured electromagnetic characteristics of the fabricated repeater coil;
• based on the second electromagnetic simulations, determining an adjusted set of design parameters for the repeater coil;
• and
• at least one of:
• modifying the fabricated repeater coil according to the adjusted set of design parameters, or
• fabricating a second repeater coil according to the adjusted set of design parameters.

A method for designing a repeater coil for wireless charging, the method comprising:

• (a) determining target structural and electromagnetic parameters for a multi-coil system in which the repeater coil increases inductive flux linkage between a transmitting wireless charging coil and a receiving wireless charging coil of a mobile device;
• (b) performing electromagnetic simulations to predict performance characteristics for the multi-coil system given different sets of design parameters for the repeater coil permitted by the target structural and electromagnetic parameters for the multi-coil system;
• (c) based on the electromagnetic simulations, determining an initial set of design parameters for the repeater coil that are predicted to produce a target set of performance characteristics for the multi-coil system;
• (d) fabricating the repeater coil according to the initial set of design parameters;
• (e) measuring performance characteristics for the multi-coil system comprising the transmitting wireless charging coil, the fabricated repeater coil, and the receiving wireless charging coil of the mobile device;
• (f) modifying the fabricated repeater coil to change a number of capacitors included in the fabricated repeater coil;
• and
• (g) repeating steps (e) and (f) to determine a number of capacitors to include in the fabricated repeater coil such that the multi-coil system most closely approximates the target set of performance characteristics.