US Patent 11387680 Coreless power transformer

A transformer system is provided that includes four magnetically coupled coils having fixed spacing geometry. The four magnetically coupled coils include a drive coil that produces magnetic fields and a load coil. All coils are coupled in the transformer system, but the first resonant coil is highly coupled with the drive coil so that the resonant coil can receive energy from the drive coil and the second resonant coil is highly coupled to the load coil so that the load coil can extract energy efficiently from the second resonant coil.