KR20160050502A

KR20160050502A - NFC Antenna Core and NFC Antenna Using the same

Info

Publication number: KR20160050502A
Application number: KR1020140148849A
Authority: KR
Inventors: 서종권
Original assignee: 서울전자통신(주)
Priority date: 2014-10-30
Filing date: 2014-10-30
Publication date: 2016-05-11

Abstract

The present invention relates to an NFC antenna with communication function and small sizes. The NFC antenna includes a core made of a magnetic material and a coil wound around the core. The magnetic core has a hexahedron shape where protrusions are formed at the four corners of one surface. The coil passes between a pair of the protrusions located at both ends of the other surface facing the core, and winds the circumference of the core.

Description

NFC Antenna Core and NFC Antenna Using the NFC Antenna [

The present invention relates to a core of an NFC antenna and an NFC antenna using the same.

An antenna is a wireless communication device that transmits and receives electromagnetic waves. The antenna is configured to resonate with respect to an electromagnetic wave having a specific frequency to transmit and receive electromagnetic waves of the corresponding frequency.

RFID technology is a technology that uses radio waves to recognize information at distant distances. RFID tags and RFID readers are needed. The tag consists of an antenna and an IC circuit, which records information in an integrated circuit and transmits information to the reader via the antenna. The information is used to identify the tagged object. RFID differs from bar code systems in that it uses radio waves instead of reading them using light.

Near Field Communication (NFC) is an abbreviation of short-range wireless communication. It has a band of 13.56MHz and is a contactless data exchange technology between terminals of up to 10cm.

NFC supports bidirectional communication, which allows information to be read and written, and is more secure than other RFIDs by encrypting information. Unlike a smart card that only stores specific information and transmits it to a reader, the NFC can also serve as a reader / writer for reading and writing tag information, as well as tag roles as needed. The NFC developed on the basis of the RFID technology has a slow data transmission speed compared to other methods such as the Bluetooth Zigbee used for the short distance communication but the communication setting time is short and the recognition malfunction is small. NFC has a variety of application fields compared with RFID because it can transmit and share contents among NFC-equipped terminals by enabling data communication between devices. NFC-equipped phones can be used as smart cards such as electronic money, electronic wallets, electronic ticketing, door keys, and ID cards, and data such as business cards, phone numbers, pictures and music can be easily shared or exchanged.

FIG. 1 schematically illustrates a general configuration of a smart phone equipped with an NFC. As shown in FIG. 1, the smart phone includes an NFC-based USIM, an NFC controller chip, and an NFC antenna. NFC USIM acts as a tag, and NFC controller chip and NFC antenna act as a reader / writer. Data communication is performed through a magnetic field generated between the antennas built in the communicating device. Active mode for reader / reader communication and passive mode for reader / tag communication. Therefore, both the active communication mode and the manual communication mode can be supported.

As an NFC antenna, an air-core coil has been conventionally used because it is inexpensive and has excellent performance. Examples of the antenna of the air-core coil include a wire formed by winding a wire coated with an insulating layer in a spiral shape and attaching to a base layer, or a metal layer formed by laminating a metal layer on a base layer and etching the wire.

In the case of such an air-core coil antenna, since the magnetic flux is generated in a direction passing through the base layer, magnetic flux passes through the base layer to reach the contacted part, thereby causing eddy currents in the component, There is a problem that the resonance frequency changes or the loss increases. In order to prevent this, the conventional NFC antenna further includes a shielding layer to prevent damage due to the magnetic flux even when the NFC antenna is installed in contact with the conductive article.

Meanwhile, in order to provide an NFC communication function in a smart device, it is necessary to mount an NFC antenna module on a smart device such as a mobile phone or a tablet PC. Since smart devices continue to be slimmed down, the thickness of the NFC antenna module installed in a smart device needs to be reduced in thickness. In the past, in order to make the module slimmer, a shielding layer was formed by lamination using a chemical process, a metal for an antenna was laminated on a shielding layer, and an antenna layer was formed through patterning and etching.

Smart device manufacturers are intensely competitive in reducing thickness. In the case of the antenna sheet formed by forming the antenna layer on the shielding layer as described above, even if the antenna sheet is manufactured in the form of a thin film, the thickness of the smart device is increased by 1MM or more. A significant contribution can be made to the reduction.

Korean Patent Publication No. 10-2013-0022820 Korean Patent No. 10-0693204

It is an object of the present invention to provide an NFC antenna that is miniaturized while preserving communication functions.

In order to achieve the above object, a core of an NFC antenna according to an embodiment of the present invention is a core of an NFC antenna including a core made of a magnetic material and a coil wound around the core, And the protrusions are formed in a hexagonal shape.

The NFC antenna according to an embodiment of the present invention is a NFC antenna including a core made of a magnetic material and a coil wound around the core, wherein the magnetic core has a hexagonal shape in which protrusions are formed at four corners of one side, do.

And the coil is wound between the two protrusions located at both ends of the opposing flank of the core and wound around the ferrite core.

The core is composed of a ferrite core, and the ferrite core is composed of 64 to 67 wt% of Fe ₂ O ₃ , 9 to 11 wt% of NiO, 19 to 23 wt% of ZnO, and 2 to 3 wt% of CuO desirable.

The core and the NFC antenna of the NFC antenna according to the embodiment of the present invention configured as described above can obtain a large induction electromotive force with a very small size and can easily assemble the coil at the time of manufacture.

1 is a schematic view of a smart device having an NFC function,
2 is a perspective view showing a ferrite core of an NFC antenna according to an embodiment of the present invention, and Fig.
FIG. 3 is a perspective view showing an NFC antenna in which a coil is wound around the core of FIG. 2. FIG.

Hereinafter, the technical structure of a core and an NFC antenna of an NFC antenna will be described in detail with reference to the accompanying drawings.

FIG. 2 is a perspective view of a core of an NFC antenna according to an embodiment of the present invention, and FIG. 3 is a perspective view illustrating an NFC antenna in which a coil is wound around a core of FIG.

The core 100 of the NFC antenna according to the embodiment of the present invention is formed by sintering a ferrite material. The core 100 is preferably composed of 64 to 67% by weight of Fe ₂ O ₃ , 9 to 11% by weight of NiO, 19 to 23% by weight of ZnO and 2 to 3% by weight of CuO for the permeability μ 1,200 . More preferably, 65.6 wt% of Fe ₂ O ₃ , 9.0 wt% of NiO, 21.2 wt% of ZnO and 3.6 wt% of CuO are sintered to produce a ferrite core. Since the core is made of ferrite, the antenna can be miniaturized due to the permittivity and the permeability of the ferrite.

As shown in FIG. 2, the ferrite core 100 is formed in a hexagonal shape so that protrusions 110 are formed at four corners on one side. The hexagonal shape can be a thin rectangular plate columnar shape. As shown in FIGS. 2 and 3, the ferrite core 100 may be formed in the shape of a rectangular plate. A terminal 111 is plated on the upper surface of one of the pair of protrusions 110 facing each other. The terminal 111 is preferably plated with a metal such as gold, silver, copper, or nickel.

The coil 200 is wound around the core 100 as shown in Fig. The coil 200 is wound around the core so as to pass between the pair of protrusions 110 and pass between the pair of the other protrusions 110. Since the coil 200 is located between the protrusions 110, the coil 200 can be assembled so as to be wound around the core 100 more easily. Both end portions of the coil 200 are electrically connected to the terminals 111 of one of the pair of projecting portions 100 facing each other. The terminal 111 is electrically connected to the NFC controller chip. The number of turns of the coil 200 is determined according to the resonance frequency of the antenna. As shown in Fig. 3, in the case of a ferrite core 100 having a rectangular plate column shape, it is preferable to wind the coil 200 through the protrusions 110 of the long-length-direction flank to wind the coil 200 in the longitudinal direction The recognition direction and the recognition distance are further improved.

Since the coil 200 is wound between the protrusions 110 as shown in FIG. 3, even when the thin coil 200 is wound on the small-sized core 110, the coil 200 can be stably wound So that it can be easily manufactured and the defect rate can be reduced.

100: Core 110: Projection
111: terminal 200: coil

Claims

1. A core of an NFC antenna including a core made of a magnetic material and a coil wound around the core,
Wherein the core is formed in a square pillar shape having protrusions on four corners of one side.

1. An NFC antenna comprising: a core made of a magnetic material; and a coil wound around the core,
Wherein the core is formed in a square pillar shape having protrusions on four corners of one side.

3. The method of claim 2,
Wherein the coil passes between a pair of protruding portions located at both ends of a facing side of the core to wind around the core.

3. The method of claim 2,
Wherein the core is a ferrite core.

5. The method of claim 4,
Wherein the ferrite core comprises 64 to 67 wt% of Fe ₂ O ₃ , 9 to 11 wt% of NiO, 19 to 23 wt% of ZnO, and 2 to 3 wt% of CuO.

3. The method of claim 2,
Wherein the core is formed with a metal-plated terminal on the upper surface of one of the pair of projections located at both ends of the opposite side of the opposite side.