This disclosure provides systems, methods and apparatus for wireless power transfer. In one aspect, an apparatus for wirelessly transmitting power is provided. The apparatus includes a first conductive structure configured to generate a first magnetic field based on a first current received from a power source. The apparatus further includes a second conductive structure configured to generate a second magnetic field based on a second current from the power source. The apparatus further includes a controller configured to determine a respective coupling coefficient between each of the first and second conductive structures and a third conductive structure configured to receive power via the first or the second magnetic field. The controller is further configured to adjust the first or second current applied to the first and second conductive structures based at least in part on the coupling coefficients.