Coil device, phase shift circuit, and communication apparatus

A coil device comprising:

• an insulating substrate;
• and
• a first input/output terminal, a second input/output terminal, a common terminal, a first coil, and a second coil, each of which is provided on the insulating substrate;
• wherein
• the first coil includes a first coil conductor with a shape wound around a first winding axis;
• the second coil includes a second coil conductor with a shape wound around a second winding axis parallel or substantially parallel to a direction of the first winding axis;
• the first coil includes a plurality of first coil conductors provided over a plurality of layers, the plurality of first coil conductors including an input/output terminal side first coil conductor with one end connected to an input/output terminal;
• the second coil includes a plurality of second coil conductors provided over a plurality of layers, the plurality of second coil conductors including an input/output terminal side second coil conductor having one end connected to an input/output terminal;
• the input/output terminal side first coil conductor is located between two second coil conductors among the plurality of second coil conductors in a direction of the second winding axis, and overlaps the two second coil conductors when viewed in a direction of the second winding axis;
• one of the two second coil conductors is the input/output terminal side second coil conductor;
• the input/output terminal side second coil conductor is between two first coil conductors among the plurality of first coil conductors in a direction of the first winding axis, and overlaps the two first coil conductors when viewed in a direction of the first winding axis;
• and
• one of the two first coil conductors is the input/output terminal side first coil conductor.