Rotation angle detection device

A rotation angle detection device for detecting a rotation angle of a rotating body rotatably provided with respect to a support body comprising:

• a magnetic circuit fixed to the rotating body, the magnetic circuit having a first magnet and a second magnet arranged opposite each other across a rotation axis of the rotating body and having a same magnetization direction, and a first yoke and a second yoke connecting same poles of the first magnet and the second magnet;
• and
• a magnetic detection unit having a magnetic detection element configured to output an electric signal according to a magnetic field in an inner region of the magnetic circuit, the magnetic detection element being fixed to the support body so that the magnetic detection element is positioned on an axis, wherein
• when a direction in which an imaginary line connecting a center of the first magnet and a center of the second magnet extends is defined as a first direction, and a direction in which the axis extends and which is perpendicular to the first direction is defined as a second direction, the first yoke and the second yoke are disposed opposite to each other in the second direction across the axis, and
• a distance between a portion of the first yoke facing a north pole of the first magnet and a portion of the second yoke facing a south pole of the first magnet and a distance between a portion of the first yoke facing a north pole of the second magnet and a portion of a second yoke facing a south pole of the second magnet are both greater than or equal to a distance between a surface of the first yoke facing the second yoke between the first magnet and the second magnet and a surface of the second yoke facing the first yoke between the first magnet and the second magnet.