Wireless power transfer to biomedical implants

A system for wireless power transfer to biomedical implants, comprising:

• a radio frequency (RF) power source;
• and
• a transmitter (TX) array comprising an excitation coil and a plurality of passive, non-overlapping resonant coils distributed about and symmetrically surrounding the excitation coil, the TX array configured to transfer power from the RF power source to a biomedical implant inserted below a skin surface of a subject when the TX array is positioned on the skin surface adjacent to the biomedical implant, wherein each resonant coil of the plurality of passive, non-overlapping resonant coils is adjacent to the excitation coil and two other resonant coils of the plurality of passive, non-overlapping resonant coils, wherein the plurality of passive, non-overlapping resonant coils couples a magnetic field originating from the excitation coil throughout the TX array allowing coupling with a receiver (RX) coil of the biomedical implant when overlapping at least a portion of the plurality of passive, non-overlapping resonant coils without overlapping the excitation coil.