Antenna device and method of setting resonant frequency of antenna device

摘要

In antenna device, a coil conductor of an antenna coil module and a conductor layer at least partially overlap. A current flows in the conductor layer to block a magnetic field generated by a current flowing in the coil conductor. A current, which flows around the periphery of an opening of the conductor layer, flows along the periphery of a slit and around the periphery of the conductor layer due to a cut-edge effect. Since magnetic flux does not pass through the conductor layer, magnetic flux attempts to bypass the conductor layer along a path in which the conductor opening of the conductor layer is on the inside and the outer edge of the conductor layer is on the outside. As a result, the magnetic flux generates relatively large loops that link the inside and the outside of a coil conductor of an antenna on a reader/writer side.

主权项

1. An electronic appliance comprising:
a casing including an inner surface and an outer surface; an antenna device; and a camera module provided in the casing and including a lens; wherein the antenna device includes:
a coil conductor having a loop shape or a spiral shape in which a winding center portion defines a coil opening; anda conductor layer that is closer to an antenna on a communication partner side than the coil conductor is relative to the antenna on the communication partner side; the conductor layer includes a conductor opening and a slit, the slit connecting the conductor opening and an outer edge of the conductor layer; when the coil conductor is viewed in plan view, the coil conductor and the conductor layer are superposed one on top of the other; the conductor layer is arranged to function as a radiator to radiate a magnetic field; at least a portion of the lens of the camera module is exposed in the conductor opening of the conductor layer; the casing includes a metal portion; and the conductor layer is defined by at least a portion of the metal portion of the casing.