KR101294579B1 - Antenna - Google Patents

Abstract

The antenna according to the embodiment has a loop shape and is divided into two parts with a middle part spaced apart from each other and resonates the first frequency signal; And a second conductive part connected to both ends of the first conductive part and including a curved line to resonate a second frequency signal.

According to the embodiment, since the multi-band signal can be processed through one antenna at the same time, it can be mounted in various RF transmission / reception devices such as RFID readers / tags, thus improving productivity, such as reducing production process and cost. have. In addition, since it is not necessary to mount multiple antennas to process the multi-band signal, the size of the RF transceiver can be minimized.

Description

Antenna {Antenna}

1 is a perspective view showing the structure of an antenna according to an embodiment;

2 is a top view illustrating some structures of an antenna according to an embodiment.

3 is a view schematically illustrating the shape of the surface current when the first frequency signal is resonated in the antenna according to the embodiment.

4 is a view schematically illustrating the shape of a radiation pattern when the first frequency signal is resonated in the antenna according to the embodiment.

5 is a graph measuring a band of a first frequency signal resonating in an antenna according to an exemplary embodiment.

6 is a view schematically illustrating the shape of the surface current when the second frequency signal is resonated in the antenna according to the embodiment.

7 is a view schematically illustrating the shape of a radiation pattern when the second frequency signal is resonated in the antenna according to the embodiment.

8 is a graph measuring a band of a second frequency signal resonating in an antenna according to an exemplary embodiment of the present invention.

Description of the Related Art

100: antenna 110: antenna unit

111: second conductive portion 112: first conductive portion

112a: first slot 112b: second slot

113: chip element 114: connecting member

120: dielectric layer 130: ground layer

In an embodiment, an antenna is disclosed.

An antenna is a device that converts an electrical signal expressed in voltage / current and an electromagnetic wave expressed in an electric field / magnetic field, and interlocks a change of an electromagnetic field outside the antenna and an electrical signal on a wire inside the antenna.

RFID (Radio Frequency IDentification) transceiver is a device that recognizes or records the information that a tag has by using radio frequency without contact. When it is used, it recognizes, tracks, It can be managed. The RFID transceiver device has a unique identification information and includes a tag (tag or transponder) attached to an object or animal, and a reader (reader or interrogator) for reading or recording the identification information of the tag.

The use of the RFID transceiver is determined according to various frequency channels assigned to the RFID channel, and the frequency channel can be largely divided into a UHF (about 900 MHz) band and a microwave (about 2 GHz) band. The transmitter and receiver are developed separately.

In particular, the antenna is also mounted as a differentiated product to fit each frequency band, a patch type antenna, a dipole type antenna, a slot type antenna and the like can be used, the structure and size is different depending on the frequency band.

Therefore, various antenna products have to be produced according to the frequency of the RF transceiver, and a transceiver for processing a multiband signal has to be provided with multiple antennas, making circuit design difficult and difficulty in minimizing product size.

Embodiments provide an antenna capable of simultaneously processing a multiband signal and having a minimized size.

The antenna according to the embodiment has a loop shape and is divided into two parts with a middle part spaced apart from each other and resonates the first frequency signal; And a second conductive part connected to both ends of the first conductive part and including a curved line to resonate a second frequency signal.

Hereinafter, an antenna according to an embodiment will be described in detail with reference to the accompanying drawings.

1 is a perspective view illustrating a structure of an antenna 100 according to an embodiment, and FIG. 2 is a top view illustrating a partial structure of an antenna 100 according to an embodiment.

1 and 2, the antenna 100 according to the embodiment includes an antenna unit 110, a chip element 113, and a connection member including a first conductor part 112 and a second conductor part 111. 114, a dielectric layer 120, and a ground layer 130.

The antenna 100 may transmit and receive a multi-band frequency signal through a single antenna structure, and may be used in various RF communication systems. However, the antenna 100 may be used in an RFID (Radio Frequency IDentification) system. To illustrate.

The dielectric layer 120 is a layer on which the antenna unit 110, the chip device 113, and the connection member 114 are mounted. The dielectric layer 120 may have a square, rectangular, and rectangular structure for efficient radiation of an RF signal. (E.g. FR-4) or an insulator (e.g. insulating film) or the like.

When the dielectric layer 120 is formed of a dielectric substrate, the copper foil on the surface of the dielectric substrate may be etched to form the shape of the first conductive portion 112 and the second conductive portion 111. Capacitive reactance of the antenna 100 may be adjusted according to the permittivity (eg, 3.5 to 4.7).

In addition, when the dielectric layer 120 is formed using an insulating film, PET film, polyimide (PI), polyethylene naphtharate (PEN), polyvinyl chloride (PVC), paper, acetate, polyester, polyethylene, poly A material such as propylene, polypropylene with calcium carbonate, acrylonitrile butadiene styrene (ABS) or plastic may be used, and the first conductive part 112 and the second conductive part 111 are conductive materials on the insulating film surface. It can be formed by applying.

In an embodiment, the dielectric layer 120 is formed using a dielectric substrate.

The antenna unit 110 includes a first conductor portion 112 and a second conductor portion 111. The first conductor portion 112 is formed in an intermediate region of the dielectric layer 120 and has a loop shape. The middle part is spaced apart and has a structure divided into two parts (hereinafter, the upper part of the two parts separated by a loop shape is referred to as "first slot 112a" and the lower part as "second slot 112b"). .

The width of the first slot 112a and the second slot 112b is determined according to the capacitance by the slots 112a and 112b and the characteristic impedance of the conductor parts 111 and 112.

The second conductive part 111 is also composed of two parts, each part of which is connected to both ends of the first conductive part 112 and extends to the side end of the dielectric layer 120, and constitutes the second conductive part 111. The feeding line has a stepped structure that is bent several times.

The first conductive part 112 and the second conductive part 111 may be formed by applying a microstrip line or a conductive material having a predetermined width (for example, 0.8 to 1.2 mm) as a line through which electric current is supplied. have.

The first and second conductive parts 112 and 111, which are divided into two parts through the first slot 112a and the second slot 112b, respectively, are symmetrical with respect to the slots 112a and 112b. The length of the first conductive portion 112 having a loop shape is shorter than that of the second conductive portion 111 having a stepped structure.

Accordingly, the first conductive part 112 resonates the first frequency signal having a relatively high band, and the second conductive part 111 resonates the second frequency signal having a low band.

The first slot 112a of the first conductive part 112 is a part which is connected through the chip element 113 to receive a current or transmit a signal received from the outside to the chip element 113, and the second slot ( 112b) is a portion where the current supplied from the first slot 112a is transmitted to both sides, and the first frequency signal is resonated.

The chip device 113 may have a built-in RF transmission and reception circuit, a control logic and a memory, and transmits / receives an RF frequency in a dual frequency band through the antenna 100. The RF signal of the chip element 113 is radiated while flowing through the first conductive part 112 and the second conductive part 111, and the first conductive part 112 and the second conductive part 111 are received. The RF signal is transmitted to the chip device 113.

Since the chip element 113 is connected between the first conductor part 112 and the second conductor part 111, there is no directionality with respect to the electrical polarity, and since the chip element 113 operates without polarity, the feed current is The first conductive portion 112 flows in both directions.

The connection member 114 is a component that connects the chip element 113 and the first slot 112a of the first conductor part 112 and may be formed using a conductive pad, a lead, or the like. The electrical connection between the 113 and the first slot 112a may be variously changed to flip chip bonding or wire bonding depending on the application.

In addition, the antenna 100 according to the embodiment may be used for an RFID tag (transponder) or an RFID reader according to the type of the chip element 130, and may be manufactured in various sizes according to the use environment. For example, the dielectric layer 120 and the ground layer 130 may have a size of about 140 mm × 20 mm and a thickness of about 1 mm.

The first conductive part 112 and the second conductive part 111 may be formed to have a width of about 1 mm and a thickness of 0.5 mm, in which the width and thickness of the two parts of the conductor parts 111 and 112 are made. The feeding lengths may be the same or different.

3 is a diagram schematically illustrating the shape of the surface current when the first frequency signal is resonated in the antenna 100 according to the embodiment, and FIG. 4 is a diagram in which the first frequency signal is resonated in the antenna 100 according to the embodiment. In this case, the shape of the radiation pattern is schematically illustrated. FIG. 5 is a graph measuring a band of a first frequency signal resonating in the antenna 100 according to the embodiment.

The first conductive part 112 having a loop shape resonates a signal (first frequency signal) of about 2 GHz band, and thus each part of the first conductive part 112 divided by the slots 112a and 112b. Is formed to have a length of about 1.5 cm, which is half the length of λ (frequency wavelength in the 2 GHz band) corresponding to about 3 cm.

Therefore, when the current supplied from the chip element 113 corresponds to a signal of about 2 GHz band, the current does not flow to the second conductive portion 111 but mostly flows along the first conductive portion 112 (see FIG. 2). Resonance occurs in the second slot 112b.

Such a resonance process of the first conductive portion 112 is illustrated in FIG. 3.

In addition, referring to FIG. 5, the band of the first frequency signal resonating in the first conductive part 112 is measured. Resonance occurs in the band 2.3446 GHz to 2.5477 GHz, and the bandwidth BW at this time is about. 0.20308 GHz, which satisfies the active RFID frequency band having a band of 2.319 to 2.516 GHz.

In FIG. 5, the y-axis represents power value (dB) and the x-axis represents frequency value (Hz).

The radiation pattern shown in FIG. 4 is an antenna 100 according to an exemplary embodiment, and the signal source is measured while sequentially moving angles θ and Φ in each axial direction from 0 degrees to 90 degrees. The characteristics of the loop antenna can be observed and the areas marked on the radiation pattern show the difference in power gain.

For reference, the standing wave ratio (VSWR) is 2.2, and the gain (dB) is measured at -10dB in the S parameter (S1.1; meaning that the input and output ports are the same).

6 is a view schematically illustrating the shape of the surface current when the second frequency signal is resonated in the antenna 100 according to the embodiment, and FIG. 7 is a diagram in which the second frequency signal is resonated in the antenna 100 according to the embodiment. In this case, the shape of the radiation pattern is a schematic view, and FIG. 8 is a graph measuring a band of a second frequency signal resonating in the antenna 100 according to the embodiment.

The second conductive portion 111 resonates a signal in a range of about 800 MHz to 900 MHz, and thus each of the second conductive portions 111 divided by the slots 112a and 112b of the first conductive portion 112. The portion is formed to have a length of about 8 cm, which is 1/4 of a length (frequency wavelength in the 800 MHz to 900 MHz band) corresponding to about 32 cm.

As described above, the second conductive part 111 may have a stepped structure that is aberrationally curved, and thus its length may be reduced, and one or more lines constituting the stepped structure may be formed as a looped line 111a. In this case, the size in the longitudinal direction can be further reduced.

1 and 2, the second conductive part 111 according to the embodiment has a second stepped curved structure, and a line connected to the first conductive part 112 is configured as a loop type line 111a. do.

For reference, in the stepped structure, the second conductive part 111 may be formed in various structures such that a line extending in a bend toward the first conductive part 112 side or toward an outer direction thereof. In consideration of the interference phenomenon caused by the current flow direction, the first conductive part 112 may be formed to face the outer direction (which is more advantageous in reducing the length).

Through such a structure, the entire length l1 of the conductor portion may be reduced from about 16 cm to about 10 cm, and the stepped curved width l2 may be formed about 2 cm.

Therefore, according to the antenna 100 according to the embodiment, the multi-band signal can be processed simultaneously and its size can be greatly reduced.

On the other hand, when the current supplied from the chip element 113 corresponds to a signal in the range of about 800 MHz to 900 MHz, the current does not flow to the first conductive portion 112 but mostly flows along the second conductive portion 111 (FIG. Resonance may occur at an end extending outward.

That is, the electric current supplied from the first slot 112a of the first conductive portion 112 flows branched from the first loop line 111a of the second conductive portion 111 and then joins at the point where the loop 111a ends. Then, the second frequency signal is resonated by flowing to the end along the remaining stepped line section.

Such a resonance process of the second conductive part 111 is illustrated in FIG. 6.

8, the band of the second frequency signal resonating in the second conductive part 112 is measured. Resonance occurs in the band D of about 0.83692 GHz to 0.96923 GHz, and the bandwidth BW at this time is about. 0.13231 GHz.

The resonant frequency band of the second conductive part 111 includes all of the European RFID (860-866MHz), North American RFID (902-930MHz), Korean RFID (908.5-915MHz), and Japanese RFID (955-957MHz) frequency bands. That's a number.

Therefore, using the antenna 100 according to the embodiment, it is possible to meet all frequency bands assigned to the RFID communication channel, and thus can be utilized in RFID transmission and reception systems such as RFID tags or RFID readers used for various purposes. .

The radiation pattern shown in FIG. 7 measures the antenna 100 according to the embodiment vertically and measures the signal source while sequentially moving the angle (θ, Φ) in each axial direction from 0 to 90 degrees. In addition, the characteristics of the dipole antenna can be observed by analyzing the power gain (dB) and the shape of the radiation pattern according to the radiation region.

In the case of the second conductive part 111, the first conductive part 112 is included therein. Even though a small amount of current leaks into the first conductive part 112, the shape of the measured radiation pattern is almost unaffected. You can see that it is close to the circle.

Although the present invention has been described above with reference to the embodiments, these are only examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains may have an abnormality within the scope not departing from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not illustrated. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

According to the antenna according to the embodiment, the following effects are obtained.

First, since the multi-band signal can be processed through one antenna at the same time, it can be mounted on various RF transmitters and receivers such as various RFID readers / tags, thus improving productivity, such as reduced production process and cost.

Second, since it is not necessary to mount multiple antennas to process multi-band signals, the size of the RF transceiver can be minimized.

Third, since a single RF transmitter and receiver can monitor multiple frequency channels and improve radio wave reception efficiency, an RF network (system) such as an RFID system and a ubiquitous sensor network (USN) system can be efficiently constructed. It becomes possible.

Claims (10)

A first conductor part having a middle portion spaced apart from each other and separated into two parts in a loop shape and resonating the first frequency signal; And And a second conductive part connected to both ends of the first conductive part and including a curved line to resonate a second frequency signal. The method of claim 1, wherein the first conductive portion and the second conductive portion An antenna that resonates an RFID signal. The method of claim 1, The first conductive unit resonates the signal of the 2GHz band, The second conductive part antenna for resonating the signal of the 800MHz to 900MHz band. The method of claim 1, wherein the first conductive portion The spaced portion is an antenna connected to the chip element. The method of claim 1, wherein the curved line is An antenna comprising a stepped structure. The method of claim 1, wherein the second conductive portion Antenna with looped lines. The method of claim 1, An antenna having a symmetrical structure with respect to the intermediate part spaced apart from the first conductive part separated into the two parts and the second conductive part connected to both ends of the first conductive part. The method of claim 1, And a dielectric plate on which the first conductive portion and the second conductive portion are formed. 9. The method of claim 8, An antenna comprising a ground plate formed under the dielectric plate. The method of claim 1, The first conductive portion has a length of 1/2 of the wavelength of the first frequency signal, And the second conductive part has a length of one quarter of the wavelength of the second frequency signal.

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