A coil-type loop antenna for a mobile device is installed in a mobile device, and includes an antenna coil which is arranged in the form of a coil wound around the outside surface of a housing of a permanent magnet structure having a permanent magnet on the inside thereof.

A coil-type loop antenna for a mobile device is installed in a mobile device, and includes an antenna coil which is arranged in the form of a coil wound around the outside surface of a housing of a permanent magnet structure having a permanent magnet on the inside thereof.

Provided are a multi-function card that has a non-contact IC card function, a magnetic stripe card function, and a function of generating a magnetic card signal and an NFC signal, a Bluetooth function capable of transmitting a signal to devices such as smartphones, includes a metallic frame, and is robust against bending or breakage, a transmission/reception sensor system used for the multi-function card or the like, and a wearable device, and the transmission/reception sensor system includes a magnetic sensor 10 including a coil 2 wound around a magnetic sensor core 1, an NFC coil 12 formed in a planar shape, and a metallic frame 13a of a loop shape which is installed along the NFC coil 12 and includes one or more cut portions.

An antenna device in which a conductive foil or an antenna pattern directly formed on the magnetic sheet without an insulating substrate such as polyimide, has a reduced thickness and may be prepared simple process. Also, with respect to the antenna device, flexibility may be improved by using a polymer-type magnetic sheet, and, since magnetic properties are excellent, the antenna device may be used for multiple applications such as NFC, WPC, and MST.

Disclosed is an electronic device which includes: a metal body including a hole defined by an inner edge thereof and extending in a first direction, wherein the metal body is defined by an outer edge thereof; and a near field communication (NFC) antenna including a coil wound about a central axis and arranged near the metal body to overlap the hole in a plan view of the metal body, wherein the inner edge and the outer edge are not connected to each other and the NFC antenna is arranged at the center of the hole along a second direction perpendicular to the first direction, and wherein the NFC antenna is arranged such that four cross points at which the NFC antenna and the inner edge cross in the plan view are formed.

Disclosed is an electronic device which includes: a metal body including a hole defined by an inner edge thereof and extending in a first direction, wherein the metal body is defined by an outer edge thereof; and a near field communication (NFC) antenna including a coil wound about a central axis and arranged near the metal body to overlap the hole in a plan view of the metal body, wherein the inner edge and the outer edge are not connected to each other and the NFC antenna is arranged at the center of the hole along a second direction perpendicular to the first direction, and wherein the NFC antenna is arranged such that four cross points at which the NFC antenna and the inner edge cross in the plan view are formed.

According to a method of preparing a conductive magnetic composite sheet, the method comprising preparing a magnetic sheet comprising a magnetic powder and a binder resin; stacking the magnetic sheet and a first conductive foil; and applying heat and pressure to the obtained stack to bond the magnetic sheet and the first conductive foil, a conductive magnetic composite sheet having excellent interlayer adhesion between the magnetic sheet and the conductive foil can be prepared while having an excellent magnetic property at NFC, WPC, and MST frequencies.

A transmission antenna includes a closed-loop core having at least two electrically-conductive windings arranged on the closed-loop core. The windings are each electrically-actuated to generate a magnetic flux along the closed-loop core in opposing directions. The transmission antenna may generate a polarized magnetic field within a plane of the closed-loop core and provide broadband transmission of a polarized signal having a relatively flat frequency response. The transmission antenna is electrically-small, and the frequency of the polarized signal is nearly independent of the size of the closed-loop core. Multiple polarized signals may be provided, each being independently and continuously controlled through actuation of the windings. The direction of the polarized signal may also be varied. Additional windings for receiving a signal may simultaneously be employed on the closed-loop core. A method for transmitting a polarized signal with the transmission antenna is also provided.

A transmission antenna includes a closed-loop core having at least two electrically-conductive windings arranged on the closed-loop core. The windings are each electrically-actuated to generate a magnetic flux along the closed-loop core in opposing directions. The transmission antenna may generate a polarized magnetic field within a plane of the closed-loop core and provide broadband transmission of a polarized signal having a relatively flat frequency response. The transmission antenna is electrically-small, and the frequency of the polarized signal is nearly independent of the size of the closed-loop core. Multiple polarized signals may be provided, each being independently and continuously controlled through actuation of the windings. The direction of the polarized signal may also be varied. Additional windings for receiving a signal may simultaneously be employed on the closed-loop core. A method for transmitting a polarized signal with the transmission antenna is also provided.

Various embodiments of a multi-mode antenna are described. The antenna is preferably constructed having a first inductor coil and a second inductor coil. A plurality of shielding materials are positioned throughout the antenna to minimize interference of the magnetic fields that emanate from the coils from surrounding materials. The antenna comprises a coil control circuit having at least one of an electric filter and an electrical switch configured to modify the electrical impedance of either or both the first and second coils.