KR20150010063A - Antenna structure for near field communication - Google Patents

Abstract

The present invention relates to a short-range communication antenna capable of securing a reliable recognition distance regardless of the relative distance between the antenna and an RFID tag. The short-range communication antenna structure includes: a base; a non-contact power reception coil unit which is arranged on the upper center part of the base and is in the shape of a loop; a first loop antenna pattern which is formed on the upper part of the base and is formed to surround the non-contact power reception coil unit while being spaced apart from the non-contact power reception coil unit; and a loop antenna including a second loop antenna pattern which is electrically connected to the loop antenna and is formed in the loop of the non-contact power reception coil unit.

Description

ANTENNA STRUCTURE FOR NEAR FIELD COMMUNICATION [0002]

The present invention relates to an antenna structure for a short distance communication. More particularly, the present invention relates to an antenna structure for a short-range communication capable of generating an induced electromotive force to perform non-contact charging and short-range communication.

BACKGROUND ART [0002] In order to operate various mobile communication terminals represented by a mobile phone, a power supply is required. For this purpose, a battery must be mounted, and a multi-purpose rechargeable battery is widely used as a battery for a mobile communication terminal.

The wired charging method has conventionally been widely used for charging the battery for the mobile communication terminal. However, the wired charging not only limits the mobility which is the greatest merit of the mobile communication terminal, but also the charging performance due to the deterioration of the charging terminal .

A non-contact (wireless) charging method has been introduced to charge a mobile phone, which is a typical mobile communication terminal. The most common principle of non-contact charging is induction current. When a mobile phone with a secondary coil installed on a primary coil installed in a solid state charger is placed on it, a few hundred kHz (for example, 300 kHz or less) An induction electromotive force is generated in the frequency band and the battery of the mobile phone is charged.

In order to apply the non-contact charging to the mobile communication terminal, a coil that can generate an induced electromotive force, that is, a loop antenna in the form of a helical coil (hereinafter referred to as an antenna) is required.

In general, the non-contact charging antenna is mounted on a battery cover of a portable telephone. Since a charging circuit to which an antenna is connected is recently miniaturized and built in a portable telephone body, only an antenna (part) remains in the battery cover.

Meanwhile, a wireless environment of RFID (Radio Frequency Identification) is widely used in mobile communication terminals apart from the environment of the non-contact charging. For example, a near field communication (NFC) When an NFC chip is installed and a non-contact type smart card such as a USIM card is attached to the RF reader, the information of the USIM card of the mobile phone is read by the RF reader by the short distance wireless communication, For example, a built-in function (e. G., An electronic money function) such as an electronic money function is realized. At this time, information exchange between the NFC chip and the RF reader is performed by supplying power for driving the USIM card by the induced electromotive force at 13.56 MHz between the coil installed in the RF reader and the coil of the NFC chip installed in the mobile phone.

In addition, an NFC chip installed in a mobile phone has been developed so that it can also function as an RFID reader and read information recorded on an external RFID tag or the like. When an NFC chip operates as an RF reader, an antenna (coil) connected to the NFC chip acts as a primary coil to transmit power, and an induced electromotive force is generated in a coil (antenna) To be realized.

That is, in order to apply an RFID system (NFC) to a mobile communication terminal, a helical coil type loop antenna capable of generating an induced electromotive force is required. An antenna for the NFC is also installed in the battery cover or the battery.

As a result, in order to mount both the non-contact charging function and the short-range wireless communication function in a mobile communication terminal represented by a mobile phone, two antennas (coils) are required to induce electromotive force in each mobile communication terminal. In this case, the recognition distance of the short distance communication may vary depending on the relative position between the antenna and the RFID tag. Therefore, there is a demand for an antenna structure for a short-range communication that can secure a recognition distance of short-distance communication stably regardless of the position between the antenna and the RFID tag.

It is an object of the present invention to provide an antenna structure for a short distance communication which can secure a stable recognition distance regardless of the relative position between the antenna and the RFID tag.

In order to accomplish one object of the present invention, an antenna structure for a short distance communication according to embodiments of the present invention includes a base, a noncontact power receiving coil portion disposed at a central portion of the upper portion of the base, And a loop antenna unit having a first loop antenna pattern formed to be spaced apart from the non-contact power receiving coil part and having a second loop antenna pattern formed in a loop of the non-contact power receiving coil part and electrically connected to the first loop antenna .

According to an embodiment of the present invention, the loop antenna may include a flexible substrate having the first and second loop antenna patterns formed on one surface thereof, and a second loop antenna pattern formed on the other surface of the flexible substrate, And a second connection line formed on the other surface of the flexible substrate and electrically connecting the first and second loop antenna patterns to each other.

In one embodiment of the present invention, the first and second loop antenna patterns may achieve capacitive coupling.

In one embodiment of the present invention, the first and second loop antenna patterns may include at least one of a conductive material formed of copper, silver-coated copper, aluminum, and conductive carbon.

In one embodiment of the present invention, the base may be made of ferrite or an electromagnetic wave absorbing material.

The antenna structure for a short-range communication according to embodiments of the present invention includes a first loop antenna pattern formed to surround and surround a portion of a non-contact power receiving coil, and a second loop antenna pattern electrically connected to the first loop antenna, By providing the loop antenna portion having the second loop antenna pattern, it is possible to secure a stable recognition distance regardless of the relative position between the loop antenna portion and the RFID tag. Particularly, even when the RFID tag is located in the loop of the non-contact power receiving coil part, the antenna structure for short range communication can have a stable recognition distance to the RFID tag.

Further, since the first and second loop antenna patterns are formed on one surface of the flexible substrate, and the connection line connecting the first and second loop antenna patterns to the other surface of the flexible substrate, 2 loop antenna patterns can be mutually stably connected.

Meanwhile, the first and second loop antenna patterns may be formed on one surface and the other surface of the flexible substrate, respectively, and the first and second loop antenna patterns may form capacitive coupling, .

1 is a plan view illustrating an antenna structure for a short-range communication according to an embodiment of the present invention.
2 is a cross-sectional view of the antenna structure for the short-range communication of FIG.
3 is a plan view for explaining an example of the coupling relationship of the first and second loop antenna patterns of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to the accompanying drawings showing embodiments of the invention. However, the present invention should not be construed as limited to the embodiments described below, but may be embodied in various other forms. The following examples are provided so that those skilled in the art can fully understand the scope of the present invention, rather than being provided so as to enable the present invention to be fully completed.

When an element is described as being placed on or connected to another element or layer, the element may be directly disposed or connected to the other element, and other elements or layers may be placed therebetween It is possible. Alternatively, if one element is described as being placed directly on or connected to another element, there can be no other element between them. The terms first, second, third, etc. may be used to describe various items such as various elements, compositions, regions, layers and / or portions, but the items are not limited by these terms .

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Furthermore, all terms including technical and scientific terms have the same meaning as will be understood by those skilled in the art having ordinary skill in the art, unless otherwise specified. These terms, such as those defined in conventional dictionaries, shall be construed to have meanings consistent with their meanings in the context of the related art and the description of the present invention, and are to be interpreted as being ideally or externally grossly intuitive It will not be interpreted.

Embodiments of the present invention are described with reference to cross-sectional illustrations that are schematic illustrations of ideal embodiments of the present invention. Accordingly, changes from the shapes of the illustrations, such as changes in manufacturing methods and / or tolerances, are those that can be expected. Accordingly, the embodiments of the present invention are not to be construed as being limited to the specific shapes of the areas described by way of illustration, but rather to include deviations in the shapes, the areas described in the drawings being entirely schematic and their shapes Are not intended to illustrate the exact shape of the regions and are not intended to limit the scope of the invention.

1 is a plan view illustrating an antenna structure for a short-range communication according to an embodiment of the present invention. 2 is a cross-sectional view of the antenna structure for the short-range communication of FIG.

1 and 2, an antenna structure 100 for a short distance communication according to embodiments of the present invention includes a base 110, a non-contact power receiving coil part 130, and a loop antenna part 150. The antenna structure 100 for short-distance communication is mounted on a surface of a battery 10 and can be contactlessly charged to the battery 10 and can acquire information from an external RFID tag, This is possible.

The base 110 may include a metal. Thus, the base 110 can block the radio wave interference between the loop antenna pattern 150 formed on the base 110 and the printed circuit board (not shown) disposed therebelow. The base 110 may be made of, for example, a ferrite material.

The noncontact power receiving coil part 130 is disposed on the upper side of the base 110. The noncontact power receiving coil part 130 is disposed on the central part of the base 110. [ The noncontact power receiving coil part 130 is a part of a wireless power charger (WPC) and is connected to the charging terminals 113 to charge the battery 10 in a non-contact manner.

The non-contact power receiving coil part 130 may have a loop shape. When the noncontact power receiving coil part 130 is positioned on the primary coil installed in the noncontact type charger, a frequency band of several hundreds of kHz (for example, 300 kHz or less) is applied between the coil part 130 and the primary coil, An induced electromotive force is generated and the battery 10 equipped with the antenna structure for short-range communication 100 can be charged.

The loop antenna unit 150 is disposed on the base 110. The loop antenna unit 150 enables short-range communication between the RFID tags. The loop antenna unit 150 is electrically connected to the local communication terminals 111.

The loop antenna unit 150 includes a first loop antenna pattern 151 formed so as to be spaced apart from the noncontact power receiving coil part and a second loop antenna pattern 151 electrically connected to the first loop antenna 151, And a second loop antenna pattern 153 formed in a loop of the second loop antenna pattern 153. [ Accordingly, the first loop antenna pattern 151 can perform close-range communication with the RFID tag located in the A1 region adjacent to the edge of the base 110, while the second loop antenna pattern 153 May be capable of short range communication with the RFID tag adjacent to the position in the A2 region corresponding to the central portion of the base 110. [ Thus, the antenna structure 100 for short-distance communication can have a constant recognition distance regardless of the relative position between the RFID tags.

The loop antenna unit 150 may further include a flexible substrate 155, first and second connection lines 156 and 157, and a second connection line 158. In this case,

The flexible substrate 155 may be made of a flexible material. The flexible substrate 155 may include, for example, a heat-resistant polymer resin, that is, an ethylene resin or a polyimide resin. The first and second loop antenna patterns 151 and 153 are formed on one surface of the flexible substrate 155.

The first connection lines 156 and 157 are formed on the other surface of the flexible substrate 155. The first connection lines 155 and 157 connect the first and second loop antenna patterns 151 and 153 to the short-distance communication pads 111, respectively. In this case, the first connection lines 156 and 157 are connected to the first and second loop antenna patterns 151 and 153 through contact vias (not shown) formed through the flexible substrate 155, Can be connected.

The second connection line 158 is formed on the other surface of the flexible substrate 155. The second connection line 158 interconnects the first and second loop antenna patterns 151 and 153. The second connection line 158 may connect the first and second loop antenna patterns 151 and 153 through contact vias (not shown) formed through the flexible substrate 155.

In one embodiment of the present invention, the first and second loop antenna patterns 151 and 153 may be formed of a conductive material such as copper, silver-coated copper, aluminum, or conductive carbon.

3 is a plan view for explaining an example of the coupling relationship of the first and second loop antenna patterns of FIG.

Referring to FIG. 3, the first and second loop antenna patterns 151 and 153 may be connected to each other through capacitive coupling. That is, the first and second loop antenna patterns 151 and 153 may be formed on different planes of the flexible substrate 155, respectively. The first and second loop antenna patterns 151 and 153 overlap in a planar manner so that the overlapped area 152 is larger than the effective area of the capacitive coupling effective area. Accordingly, the first and second loop antenna patterns 151 and 153 may be electrically connected to each other through capacitive coupling. As a result, it is possible to easily form the antenna structure 100 for short range communication including the first and second loop antenna patterns 151 and 153 by omitting the separate process for forming the via contact. Also, the antenna structure 100 for short range communication may have a simpler structure.

Claims (5)

Base;
A noncontact power receiving coil portion disposed at a central portion of the upper portion of the base and having a loop shape; And
A first loop antenna pattern disposed at an upper portion of the base and spaced apart from the noncontact power receiving coil portion and a second loop antenna pattern electrically connected to the first loop antenna and formed in a loop of the non- And a loop antenna portion having a pattern. The antenna device according to claim 1,
A flexible substrate on which the first and second loop antenna patterns are formed;
First connection lines formed on the other surface of the flexible substrate and electrically connecting the first and second loop antenna patterns to the antenna pads, respectively; And
And a second connection line formed on the other surface of the flexible substrate and electrically connecting the first and second loop antenna patterns to each other. 2. The antenna structure for a short-range communication according to claim 1, wherein the first and second loop antenna patterns are capacitively coupled. The antenna structure for a short distance communication according to claim 1, wherein the first and second loop antenna patterns are at least one selected from the group consisting of copper, silver-coated copper, aluminum, and conductive carbon. The antenna structure for a short-range communication according to claim 1, wherein the base is made of ferrite or an electromagnetic wave absorbing material.

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