Coil element, antenna device, and electronic device

A coil element comprising:

• an insulator;
• a first outer electrode, a second outer electrode, a third outer electrode, and a fourth outer electrode on a surface of the insulator;
• and
• a first coil and a second coil each including a plurality of conductor patterns in the insulator;
• wherein
• the first coil includes:
• at least two layers of first conductor patterns electrically connected to the first outer electrode;
• and
• a second conductor pattern on the first conductor patterns and electrically connected to the second outer electrode;
• the layers of the first conductor patterns are connected in parallel to each other and the second conductor pattern is connected in series to the first conductor patterns;
• the second coil includes:
• at least two layers of third conductor patterns electrically connected to the third outer electrode;
• and
• a fourth conductor pattern laminated on the third conductor patterns and electrically connected to the fourth outer electrode;
• the layers of the third conductor patterns are connected in parallel to each other and the fourth conductor pattern is connected in series to the third conductor patterns;
• the first coil and the second coil are positioned in the insulator such that the second conductor pattern and the fourth conductor pattern face each other in a lamination direction of the insulator;
• an opening of the first coil overlaps an opening of the second coil when viewed in the lamination direction of the insulator;
• and
• an area of a portion where the second conductor pattern overlaps the fourth conductor pattern is equal to or smaller than about 80% of an area of a portion where at least one of the second conductor pattern and the fourth conductor pattern exists when viewed in the lamination direction of the insulator.