Antenna coil comprising plurality of coil portions

摘要

Provided is an antenna coil capable of forming a magnetic field in a desired direction in an efficient manner, while suppressing leakage of magnetic flux into a space other than the space in which the magnetic field is formed. The antenna coil includes a main coil portion formed by winding a length of conductor wire around a first reference axis and an auxiliary coil portion formed by winding the conductor wire around a second reference axis. The second reference axis is set to intersect the magnetic flux of the main coil portion at an axial end of the auxiliary coil portion. The main coil portion and the auxiliary coil portion are connected to together form a closed circuit.

主权项

1. An antenna coil, comprising:
a main coil portion formed by winding a length of conductor wire around a first reference axis; and an auxiliary coil portion formed by winding a length of conductor wire around a second reference axis different from the first reference axis, the auxiliary coil portion having a smaller diameter than a diameter of the main coil portion, the auxiliary coil portion being disposed such that a magnetic flux of the main coil portion is deflected in a direction along the second reference axis; wherein the main coil portion and the auxiliary coil portion are connected in series or in parallel to form a closed circuit, and wherein when current flows simultaneously in the main coil portion and the auxiliary coil portion, the magnetic flux of the main coil portion has directivity such that the magnetic flux of the main coil portion spreads on a side where the auxiliary coil portion is absent relative to a side where the auxiliary coil portion is present and the magnetic flux of the main coil portion bends and returns via the auxiliary coil portion as a bypassing circuit.