Stacked coil structure and electronic device including the same

An electronic device comprising:

• a coil unit;
• a power transmission circuit electrically connected to the coil unit;
• and
• a control circuit configured to wirelessly transmit power using the coil unit,
• wherein the coil unit includes:
• a first coil wound in a first shape by a first number of turns, the first shape including a first layer and a second layer having an area narrower than the area of the first layer, and
• a second coil wound in a second shape by a second number of turns, the second coil being disposed above the first layer to overlap at least a portion of the first layer.

An electronic device comprising:

• a power transmission circuit configured to generate power;
• and
• a coil assembly electrically connected to the power transmission circuit and configured to wirelessly transmit the power,
• wherein the coil assembly includes:
• a first coil module including a first coil wound by a first number of turns, and a second coil wound by a second number of turns smaller than the first number of turns, the second coil being electrically connected to the first coil and disposed above the first coil, and
• a second coil module including a third coil wound by a third number of turns and disposed above the first coil adjacent to the second coil, a portion of the third coil overlapping the first coil, and a fourth coil wound by a fourth number of turns smaller than the third number of turns, the fourth coil being electrically connected to the third coil and disposed below the third coil adjacent to the first coil.