Patent ID: 8362868

Claim:
A plane coil comprising: a plurality of conductive wires which are generally parallel to each other, wherein the conductive wires are arranged in a plane and spirally wound, coil ends of the respective conductive wires are electrically connected to each other at a coil lead-out portion such that the conductive wires are connected in parallel, positions of the parallel conductive wires relative to each other are switched at a plurality of changing positions on the plane, the conductive wires have an even number of the conductive wires in parallel in each spiral loop, a first coil comprising a first half of the even number of the conductive wires is stacked vertically adjacent to a second coil comprising a second half of the even number of the conductive wires, the first coil and the second coil have at least one of equal coil diameters and equal numbers of turns, at least one position of the first half of the even number of the conductive wires relative to at least one other position of the first half of the even number of the conductive wires are switched at least one of the plurality of the changing positions on the plane, and the first half of the even number of the conductive wires are connected in series with the second half of the even number of the conductive wires.