Patent ID: 7710341

Claim:
A portable electronic device comprising: a rectangular circuit board having a longitudinal dimension and a lateral dimension, the longitudinal dimension being larger than the lateral dimension; and an antenna coil provided on the circuit board, the antenna coil including: a rod-shaped magnetic core, and a coil wound around the magnetic core, the coil including a first coil portion, a second coil portion, and an unwound portion at an intermediate portion of the magnetic core in a longitudinal direction thereof, wherein winding directions of the first coil portion and the second coil portion differ from each other, and wherein a length X of the magnetic core and a distance Y between two points at which a virtual line formed by projecting a central line of the magnetic core in an axial direction thereof onto the circuit board intersects an outer periphery of the circuit board along the lateral dimension thereof, satisfies Y≧X≧0.8Y.