US Patent 11804874 Method and apparatus for magnetic field communication

An antenna device for magnetic field communication may include: a first coil; a second coil; a third coil; a first capacitor connected to a 1-1 terminal of the first coil; a second capacitor connected to a 2-1 terminal of the second coil; a third capacitor connected to a 3-1 terminal of the third coil; and an input port including a first input terminal connected to a 1-2 terminal of the first coil, a 2-2 terminal of the second coil, and a 3-2 terminal of the third coil, and a second input terminal connected to the first capacitor, the second capacitor, and the third capacitor.