KR100906915B1 - antenna - Google Patents

Abstract

According to an embodiment of the present invention, there is provided an antenna comprising: a first conductive part including a metal line forming a polygonal structure and a side of the polygonal side spaced apart from each other; A dielectric plate on which the first conductive portion is formed; And a ground plate formed under the dielectric plate.

According to the embodiment, since the magnetic field and surface current of the antenna are maximized and high-gain near-field communication is possible, the RFID communication area can be prevented from narrowing according to the use environment. In addition, it is possible to reliably transmit and receive signals regardless of the packing material of the goods, the type of contents, transport type, etc., and can maximize the characteristics of the HF band and UHF band signals, so that barcodes can be replaced by RFID transceivers. Effectively build distribution logistics and ID recognition system.

RFID, shopping systems, antennas, slots, conductors, surface current, electric field, magnetic field, distribution logistics, barcode

Description

Antenna {Antenna}

An embodiment discloses an 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.

Such RFID technology has a wide range of applications, and it is expected that various technologies and services will be combined to make life in the real world more convenient. However, technology development is still in its infancy, and the application services used are also very limited in the form of transportation cards, identity cards, animal management chips, and the like.

In the future, it is expected to increase the convenience of buyers by applying RFID technology to shopping spaces such as large marts, and to increase the convenience of buyers. RFID channel band and UHF (Ultra HF; 400-915 MHz) channel band are expected to be used.

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 of an internal tag of the antenna.

However, there are many restrictions in processing signals according to the characteristics of the RFID channel band and the antenna characteristics.

For example, when a buyer moves a tagged item in a cart or processes an automatic payment through RFID communication, a large number of tags are formed in a narrow space, which greatly increases the probability of interference in a received signal. .

In addition, in the case of a can made of a conductor, a water bottle and a vial having a high dielectric constant, the impedance value of the tag antenna is changed to achieve conjugate matching, and thus the recognition distance of the tag becomes very narrow.

In this case, the magnetic field (H-field) is relatively small compared to the electric field (E-field) and the surface current is weakened, so that the reception signal cannot be properly processed.

In addition, most antennas currently inserted in a tag form a loop and dipole structure, which has a null region in a scattering pattern of radio waves.

When the radio wave from the reader is incident toward the null area of the antenna, the power of the energy signal is extremely limited, so that the tag recognition rate is remarkably lowered.

Embodiments provide an antenna that facilitates near-field communication by maximizing magnetic field (H-field) and surface current.

The embodiment provides an antenna capable of stably transmitting and receiving a signal regardless of the type of packaging material and contents, transport type, etc. of a shopping system when building a shopping system through an RFID transceiver device using an HF band, a UHF band, or the like.

According to an embodiment of the present invention, there is provided an antenna comprising: a first conductive part including a metal line forming a polygonal structure and a side of the polygonal side spaced apart from each other; A dielectric plate on which the first conductive portion is formed; And a ground plate formed under the dielectric plate.

According to the embodiment, the following effects are obtained.

First, since the magnetic field and surface current of the antenna are maximized and high-gain near-field communication is possible, the RFID communication area can be prevented from narrowing according to the use environment.

Second, it is possible to reliably transmit and receive signals regardless of the packing material of the goods, the type of contents, transport type, etc., and can maximize the characteristics of the HF band and UHF band signals, so that barcodes can be replaced by RFID transceivers. Effectively build distribution logistics and ID recognition system.

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

1 is a perspective view showing the structure of the antenna 100 according to the first embodiment, and FIG. 2 is a top view showing the structure of the antenna 100 according to the first embodiment.

1 and 2, the antenna 100 according to the first embodiment includes a conductor part 110, a chip element 140, and a connection including a first conductor part 111 and a second conductor part 112. The member 141, the dielectric layer 120, and the ground layer 130 are included.

The antenna 100 may be used in various RF communication systems, but may be used in an RFID (Radio Frequency IDentification) system for processing signals in the HF band or the UHF band.

The dielectric layer 120 is a layer on which the conductor part 110, the chip device 140, and the connection member 141 are mounted. The dielectric layer 120 may have a square or rectangular shape such as a square shape 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 implement the first conductive portion 111 and the second conductive portion 112, and the dielectric constant of the dielectric layer 120 may be 3.5 to 4.7) to adjust the capacitive reactance of the antenna 100. For example, in an embodiment, the dielectric layer 120 may be formed to a thickness of about 1 mm, and may have a dielectric constant of about 4.6.

In addition, when the dielectric layer 120 is formed using an insulating film, PET film, polyimide (PI), polyethylene naphtharate (PEN), polyvinyl chloride (PVC), acetate, polyester, polyethylene, poly A material such as propylene or polypropylene having calcium carbonate may be used, and the first conductive part 111 and the second conductive part 112 may be formed by applying a conductive material to the insulating film.

The conductor part 110 includes a first conductor part 111 and a second conductor part 112, wherein the first conductor part 111 and the second conductor part 112 are formed of the dielectric layer 120. It is formed in the middle region and includes a metal line close to a circle.

The first conductive part 111 includes a metal line 111a and a passive element 111b.

The metal line 111a constituting the first conductive part 111 is a portion for resonating a signal, and forms a polygonal structure close to a circle, and slots are formed by spaced sides of the polygon. Hereinafter, for convenience of description, the metal line 111a between the slot and the slot is referred to as a "unit metal line".

The passive element 111b is positioned between a slot, that is, the unit metal line 111a to electrically connect the unit metal line 111a, and may be provided as a capacitor.

As described above, according to the antenna 100 structure according to the first embodiment, the surface current and the electromagnetic field, in particular the magnetic field, are realized by implementing the loop type antenna by using the unit metal line 111a and the passive element 111b. It can be evenly distributed and its strength can be strong.

In addition, as the magnetic field becomes stronger, the null area may be minimized.

Although the first conductive portion 111 and the second conductive portion 112 are closer to the circular shape, the signal characteristics are better, but there is a limit in changing the capacitance characteristics by inserting the passive element 111b, that is, the passive element ( Since the number of insertions of 111b) is limited, it is preferable to form a polygonal structure of octagonal to 32 octagonal.

Thus, for example, when 16 unit metal lines 111a are provided so that the first conductive portion 111 forms a hexagon, 16 slots and 15 passive elements 111b are provided.

For reference, the chip element 140 is positioned in the other slot not filled by the passive element 111b, which will be described later.

When the first conductor unit 110 resonates a signal in the UHF band, the first conductor unit 110 may be about 1/4 of a length of about 32 cm in frequency wavelength lambda (the frequency wavelength in the 800 MHz to 900 MHz band). It may be formed to have a length of 8 cm.

In addition, since the length of the unit metal line 111a is constant, the influence of the capacitance on the resonance signal due to the passive element 111b may be constantly applied to the entire region.

On the other hand, when the capacitance component is induced to change the signal characteristics, the slot structure may be used without the passive element 111b.

In this case, the width, thickness, and separation distance of the unit metal line 111a may be determined according to the capacitance according to the size of the slot and the characteristic impedance of the first conductive part 111.

In the embodiment, the passive element 111b is used because it is determined that the passive element 111b can be implemented more easily than the slot itself.

The second conductive portion 112 has a diameter smaller than that of the first conductive portion 111 and has the same polygonal structure as that of the first conductive portion 111. However, the first conductive portion 112 is formed without a slot and is formed as a single line. It is different from the body part 111.

The second conductive portion 112 is positioned inside the first conductive portion 111, and a polygonal side (unit metal line) forms a polygonal side (unit metal line) of the first conductive portion 111. It is formed to correspond to the center point.

The second conductive part 112 may cause a coupling phenomenon with the first conductive part 111 to amplify the size of the magnetic field to a larger value, thereby increasing the antenna gain.

The unit metal lines of the first conductive part 111 and the second conductive part 112 are arranged in alignment to induce a smooth coupling phenomenon.

3 is a perspective view illustrating a part of the structure A of the first conductive part 111 of the antenna 100 according to the first embodiment.

The passive element 111b may be connected to the unit metal line 111a through a connection member such as a wire, or may be directly bonded to the end B of the unit metal line 111a as shown in FIG. 3.

1 and 2, the chip element 140 is positioned in the remaining slot where the passive element 111b is not disposed, and is electrically connected to the unit metal lines 111a on both sides.

The chip device 140 may have a built-in RF transmission and reception circuit, a control logic and a memory, and transmit and receive an RF frequency through the conductor unit 110.

The RF signal of the chip element 140 is radiated while flowing through the first conductor part 111, and the first conductor part 111 transmits the resonant RF signal to the chip element 140.

Since the chip element 140 is connected to the first conductive part 111, there is no direction for electrical polarity, and since the chip element 140 operates without polarity, the feed current is supplied to the unit metal lines 111a on both sides. Can flow.

The connection member 141 is a component that connects the chip element 140 and the unit metal line 111a. The connection member 141 may be formed using a conductive pad, a lead, or the like, and the chip element 140 and the unit metal line 111a. The electrical connection can be made in a variety of ways, such as flip chip bonding or wire bonding.

4 is a top view showing the structure of the antenna 200 according to the second embodiment.

Referring to FIG. 4, the antenna 200 according to the second embodiment includes a conductor part 210, a chip element 240, and a connection member including a first conductor part 211 and a second conductor part 212. 241, dielectric layer 220, and a ground layer (not shown).

The antenna 200 according to the second embodiment is different from the first embodiment in that the second conductive portion 212 is formed outside of the first conductive portion 211 and the chip element 240 has the first characteristic. The form of connection with the conductor portion 211 is different.

Hereinafter, repeated description of the second embodiment will be omitted.

The first conductive portion 211 is composed of a plurality of unit metal lines 211a and passive elements 211b in the same manner as in the first embodiment.

However, as shown in FIG. 4, an end 241 of the unit metal line 211a connected to the chip element 240 is partially extended to the outside (or inside) of the polygonal structure, and the chip element 240 ) Is connected to the end 241 of the partially extended unit metal line 211a.

The length of the unit metal line 211a connected to the chip element 240 and the length of the unit metal line 211b connected to the passive element 211b are maintained while maintaining the overall structure of the unit metal line 211a close to a circle. It is for making length equal.

In general, since the chip device 240 has a larger size than the passive device 211b, the length of the unit metal line 211b may be kept constant by adjusting the position of the chip device 240.

5 is a top view showing the structure of the antenna 300 according to the third embodiment.

Referring to FIG. 5, the antenna 300 according to the third embodiment includes a conductor part 310 and a chip including a first conductive part 311, a second conductive part 312, and a third conductive part 313. The device 340 includes a connection member 341, a dielectric layer 320, and a ground layer (not shown).

In addition, the first conductive portion 311 includes a unit metal line 311a and a passive element 311b as in the first and second embodiments described above.

The first conductive part 311 according to the third embodiment corresponds to the first conductive part 111 of the first embodiment, and the second conductive part 312 and the third conductive part 313 according to the third embodiment. Corresponds to the second conductive parts 112 and 212 of the first and second embodiments.

That is, the second conductive portion 312 and the third conductive portion 313 according to the third embodiment are substantially the same components that cause a coupling phenomenon with the first conductive portion 311, and may be formed in different sizes. The points provided on the inside and the outside of the one conductor portion 311 are different.

Hereinafter, repeated description of the third embodiment will be omitted.

6 is a view schematically illustrating the shape of the surface current when the antenna 100 according to the first embodiment resonates, and FIG. 7 illustrates the shape of a radiation pattern when the antenna 100 according to the first embodiment resonates. It is a schematic diagram.

8 is a view schematically illustrating the shape of the magnetic field formed when the antenna 100 according to the first embodiment resonates, and FIG. 9 illustrates a signal resonated by the antenna 100 according to the first embodiment. This is a graph measuring the band.

In a typical loop antenna, the surface current is maximized at two points on the mutually opposite circle (eg + Y axis, -Y axis) and then towards the other two points (eg + X axis, -X axis). It is getting weaker.

Referring to FIG. 6, it can be seen that the surface current has an even distribution under the influence of the passive element 111b.

The radiation pattern shown in FIG. 7 measures the antenna 100 according to the embodiment vertically and measures the signal source while sequentially moving angles θ and Φ in the respective axial directions from 0 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 frequency efficiency in the measurement is 0.9523 (reference is higher efficiency as close to 1) and the gain (dB) is 3.306 dB in the S parameter (S1.1; meaning that the input and output ports are the same). Was measured.

As shown in FIG. 7, the antenna 100 according to the first embodiment has an even radiation pattern as the strength of the magnetic field signal is increased and the region is wide, and the null region is significantly reduced.

Referring to FIG. 8, it can be seen that the magnetic field is evenly distributed along each unit metal line 111a based on the region where the passive element 111b is located.

In addition, in the case of the general loop antenna, the strength of the magnetic field is about 7.62 A / m, while in the first embodiment, it is measured as about 48.1 A / m.

Referring to FIG. 9, the band of the resonant signal in the conductor unit 110 of the first embodiment is measured. Resonance occurs in the band D of about 0.89333 GHz to 0.92573 GHz, and the bandwidth BW at this time is about 0.032398 GHz. to be.

The resonance frequency band of the conductor unit 110 of the first embodiment is a numerical value that includes both domestic and international RFID frequency bands.

Therefore, by using the antenna 100 according to the first embodiment, it is possible to satisfy all frequency bands allocated to the RFID communication channel, and thus be used in an RFID transmission / reception system such as an RFID tag or an RFID reader that is used for various purposes. Can be.

FIG. 10 is a view schematically illustrating the shape of the surface current when the antenna 200 according to the second embodiment resonates. FIG. 11 illustrates the shape of a radiation pattern when the antenna 200 according to the second embodiment resonates. It is a schematic diagram.

12 is a view schematically illustrating the shape of the magnetic field formed when the antenna 200 according to the second embodiment resonates, and FIG. 13 illustrates a signal resonated by the antenna 200 according to the second embodiment. This is a graph measuring the band.

Referring to FIG. 10, as in the first embodiment, it can be seen that the surface current of the antenna 200 has an even distribution under the influence of the passive element 211b.

In the measurement of the radiation pattern shown in FIG. 11, the frequency efficiency was 0.6445, and the gain (dB) was measured as 0.7476 dB in the S parameter (S1.1).

As shown in FIG. 11, the antenna 200 according to the second embodiment has a stronger intensity of the magnetic field signal and a wider area than the first embodiment, and the null area is further reduced.

Referring to FIG. 12, it can be seen that the magnetic field is evenly distributed along each unit metal line 211a based on the region where the passive element 211b is located.

In addition, the size of the magnetic field of the antenna 200 according to the second embodiment is about 47.7 A / m.

Referring to FIG. 13, a band of a signal resonating in the conductor unit 210 of the second embodiment is measured. Resonance occurs in the band D of about 0.89725 GHz to 0.91953 GHz, and the bandwidth BW at this time is about 0.032273 GHz. to be.

The present invention has been described above with reference to the preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications not illustrated above are possible. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

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

2 is a top view showing the structure of an antenna according to the first embodiment;

3 is a perspective view showing a partial structure of a first conductive part of an antenna according to the first embodiment;

4 is a top view showing the structure of an antenna according to a second embodiment;

5 is a top view showing the structure of an antenna according to a third embodiment;

FIG. 6 is a diagram schematically illustrating the form of surface current when the antenna according to the first embodiment is resonated. FIG.

7 is a view schematically illustrating the shape of a radiation pattern when the antenna according to the first embodiment is resonated.

8 is a diagram schematically illustrating the shape of a magnetic field formed when the antenna according to the first embodiment resonates.

9 is a graph measuring a band of a signal resonating in an antenna according to a first embodiment;

10 is a diagram schematically illustrating the form of surface current when the antenna according to the second embodiment is resonated.

11 is a view schematically illustrating the shape of a radiation pattern when the antenna according to the second embodiment resonates.

FIG. 12 is a diagram schematically illustrating the shape of a magnetic field formed when the antenna according to the second embodiment resonates. FIG.

FIG. 13 is a graph measuring a band of a signal resonating in an antenna according to a second embodiment; FIG.

Claims (14)

A first conductive part comprising a metal line forming a polygonal structure and the sides of the polygon being spaced apart from each other to form a slot; A dielectric plate on which the first conductive portion is formed; An antenna comprising a ground plate formed under the dielectric plate. The method of claim 1, wherein the first conductive portion And a passive element positioned between the slots to electrically connect the spaced metal lines. The method of claim 1, A second conductive part including a metal line having the same polygonal structure as the first conductive part and formed inside the first conductive part; And a metal line having the same polygonal structure as the first conductive part, and including at least one of the third conductive parts formed outside the first conductive part. The method of claim 1, wherein the first conductive portion An antenna forming a polygonal structure of one of octagons and 32 octagons. The method of claim 1, And a chip device positioned in one of the slots to electrically connect the spaced metal lines. The method of claim 3, And an edge forming a polygon of the first conductive portion and a side forming a polygon of the second conductive portion or the third conductive portion correspond to each other in parallel. The method of claim 2, wherein the passive element An antenna comprising a capacitor. The method of claim 2, wherein the passive element Connected to the spaced metal line through a connecting member, or And bonded directly to the end of the metal line. The method of claim 5, wherein the chip element Connected to the spaced metal line through a connecting member, or And bonded directly to the end of the metal line. The method of claim 5, The metal line end of the first conductive portion connected to the chip element is partially extended to the inside or the outside of the polygonal structure, And the chip device is connected to the partially extended metal line end. delete delete The method of claim 1, And the first conductive part has a length equal to one quarter of a wavelength of a resonant frequency signal. The method of claim 1, wherein the first conductive portion And the size of the slot is adjusted to generate a capacitance component.

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