Design methodology for a high-Q self-resonant coil for medical and wireless-power applications

A high-Q self-resonant coil for medical, wireless power transfer, induction cooking, or induction heating applications is described. Stacked layers of conductor and dielectric provide the resonant capacitance while the use of many thin foil layers parallel to the magnetic field minimizes conductor losses. Integration of the resonant capacitor avoids the need for high-current terminations and balances current flow between conductor layers. Through the use of different conductor and dielectric thicknesses and materials, the approach can be applied at a wide range of frequencies. An example of a 160 kHz coil for a medical application provides an order-of-magnitude reduction in losses.