KR20090066899A - Antenna - Google Patents

Abstract

An antenna is provided to improve transmission and reception performance by maximizing an antenna gain through a control of an energy flow of a radiating signal and securing a wide grounding surface. An antenna(100) includes a conductor layer(110), a first dielectric layer(120), a second conductor layer(130), and a second dielectric layer(140). A slot is formed at the first conductor layer. The first dielectric layer is formed under the first conductor layer. The second conductor layer is formed under the first dielectric layer. The second conductor layer has a grating structure. The second dielectric layer is formed under the second conductor layer. A grounding layer is formed under the second dielectric layer.

Description

Antenna {Antenna}

An embodiment discloses an antenna.

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. The antenna interworks with a change in 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. It can recognize, track, and manage a tagged object or person. It becomes possible. The RFID transceiver device has 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 identification information of the tag.

In particular, the tag premise of mobility has a limitation in size, so there is a lot of difficulty in designing the arrangement of the antenna.

For example, a film antenna having a printed conductor is used as a tag antenna of a dipole type. When the tag antenna is attached to a ground plane, the tag antenna is short-circuited and cannot perform a function as an antenna.

In addition, for conjugate matching with a tag chip having a capacitive impedance, the tag antenna should have an inductive impedance, but it is difficult to implement this in the structure of a film-type tag antenna.

Therefore, the tag antenna also has to be produced in various sizes and shapes according to the type of tag chip products, there is a problem that the production efficiency is lowered and mass production is difficult.

At present, the product has been developed by improving the grounding structure of the tag antenna to manufacture the integrated ground plane integrally, but in order to avoid short-circuit condition, it is necessary to secure a certain height so that the size is large and the price is expensive. It is a constraint to produce the tag product of.

Embodiments provide an antenna that maximizes antenna gain by adjusting the energy flow of a radiated signal, and provides an antenna having a small and wide ground plane to improve transmission and reception performance.

In accordance with an embodiment, an antenna includes a first conductor layer having a slot; A first dielectric layer formed under the first conductor layer; And a second conductor layer formed under the first dielectric layer and forming a lattice structure.

According to the embodiment, the following effects are obtained.

First, since the energy radiated backwards can be concentrated forward, the antenna gain can be improved and the transmission and reception efficiency can be improved.

Second, since the ground plane can be secured even though it is small, the transmission and reception performance of the antenna can be improved, and the antenna can be easily installed in a device having a limited arrangement space such as a tag.

Third, since the impedance of the antenna can be adjusted by using a short pin, it is possible to match various impedances of the tag chip with a single antenna product.

Fourth, since the PIFA structure can be manufactured in the form of a printed board that can be easily processed, it is possible to expand the field of use of the antenna, to mass-produce, and to lower the production cost.

Fifth, by using the antenna according to the embodiment it is possible to manufacture a small but inexpensive tag product.

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

1 is a perspective view illustrating the structure of the antenna 100 according to the first embodiment, FIG. 2 is a perspective view illustrating the structure of the second conductor layer 130 according to the first embodiment, and FIG. Is a side cross-sectional view of the antenna 100 according to the first embodiment when it is cut based on the display line A-A '.

1 to 3, the antenna 100 according to the first embodiment includes a first conductor layer 110, a first dielectric layer 120, a second conductor layer 130, a second dielectric layer 140, The ground layer 150 includes a chip device 160 and a connection member 162.

The antenna 100 may be used in various RF communication systems, but the first embodiment exemplifies that the antenna 100 is used in an RFID (Radio Frequency IDentification) tag using a frequency in the 900 MHz band.

The first conductor layer 110 is formed on the first dielectric layer 120, and the second conductor layer 130 is formed between the first dielectric layer 120 and the second dielectric layer 140.

The ground layer 150 is formed under the second dielectric layer 140.

In an embodiment, two types of short pins are provided, and the first short pins 112 may include the first dielectric layer 120, the second conductor layer 130, and the second dielectric layer 140. Through it, the first conductor layer 110 and the ground layer 150 are electrically connected to each other.

In addition, the second shorting pin 132 penetrates through the second dielectric layer 140 to electrically connect the second conductor layer 130 and the ground layer 150.

The first dielectric layer 120 and the second dielectric layer 140 may have a square structure such as square or rectangular for efficient radiation of the RF signal, and may be formed of a dielectric substrate (eg FR-4) or an insulator (eg insulation). Film) or the like.

When the first dielectric layer 120 and the second dielectric layer 140 are formed of a dielectric substrate, copper foil is formed on the substrate surface and the copper foil is etched to form the first conductor layer 110 and the second conductor layer 130. ), The ground layer 150 may be formed, and the capacitive reactance of the antenna 100 may be adjusted according to the dielectric constant (eg, 3.5 to 4.7) of the substrate.

For example, the first dielectric layer 120 and the second dielectric layer 140 may be formed of an FR4 substrate.

In addition, when the first dielectric layer 120 and the second dielectric layer 140 are formed using an insulating film, PET film, polyimide (PI), polyethylene naphtharate (PEN), polyvinyl chloride (PVC), Material such as paper, acetate, polyester, polyethylene, polypropylene, polypropylene with calcium carbonate, acrylonitrile butadiene styrene (ABS) or plastic may be used, and the first conductor layer 110 and the second conductive material may be used. The body layer 130 and the ground layer 150 may be formed by applying a conductive material to the insulating film surface.

In an embodiment, the first dielectric layer 120 and the second dielectric layer 140 may be formed of a FR4 substrate through a printed circuit board (PCB) process.

The first conductor layer 110 is a line through which a current transmitted from the chip element 160 or a current by an energy signal in the air flows, and has a rectangular plate shape in which a “U” -shaped slot S1 is formed.

The interval between the slots S1 causes a capacitance component and may be adjusted according to characteristic impedance of the first conductor layer 110 and the second conductor layer 130.

The chip device 160 is positioned in the slot S1 and is electrically connected to the first conductor layer 110. At this time, in consideration of the current flow, the chip element 160 is preferably located in the middle portion of the left and right symmetry of the "U" -shaped slot (S1).

The chip device 160 is die-bonded to the first dielectric layer 120 exposed through the slot S1, and the first conductor layer 110 across the slot S1 through the connection member 162. ) Is electrically connected.

The chip device 160 may include an RF transceiver circuit, a control logic, a memory, and the like, and transmit and receive an RF frequency through the first conductor layer 110.

Since the chip element 160 is connected to the first conductor layer 110, there is no directionality with respect to the electrical polarity, and since the chip element 160 operates without the polarity, the feed current is the “U” slot ( It can flow in both directions along S1).

The connection member 162 is a component that connects the chip element 160 and the first conductor layer 110, and may be formed using a conductive pad, a lead, and the like, and the chip element 160 and the Electrical connection of the first conductor layer 110 may be variously performed by flip chip bonding or wire bonding.

In addition, the antenna 100 according to the first embodiment may be used for the RFID tag or the RFID reader according to the type of the chip element 160, and may be manufactured in various sizes according to the usage environment. The first dielectric layer 120 and the second dielectric layer 140 may have a size of about 140 mm × 20 mm and a thickness of about 1 mm. The first conductor layer 110 and the second conductor layer 130 may have a thickness of about 0.5 mm, and the slot S1 may have a width of about 1 mm.

As shown in FIGS. 2 and 3, the second conductor layer 130 includes a plurality of unit grids to form a lattice structure. The unit grids may have one or more of a circular shape and a multi-layered shape.

The second conductor layer 130 may improve the gain of the antenna 100 by combining energy radiated to the rear of the antenna 100 through the lattice structure in the direction of the first conductor layer 110.

Therefore, in order to form a constant electromagnetic field in the entire region of the antenna 100, the unit grids may be regularly arranged at predetermined intervals. In the first embodiment, the unit grids have a rectangular shape similar to that of a checkerboard.

The unit grids of the second conductor layer 130 are connected to the ground layer 150 through the second short circuit pins 132. In the first embodiment, one unit of the second short circuit pins 132 is provided per unit grid. It is illustrated that 132 is formed.

In the first embodiment, the first short-circuit pin 112 is described as one formed on both sides of the end portion of the first conductor portion 110, the number and position can be adjusted in various ways.

In addition, the first short circuit pin 112 penetrates the first dielectric layer 120, the second conductor layer 130, and the second dielectric layer 140 to pass through the unit grid or between the unit grids. It can be formed through. For example, when the first shorting pin 112 passes through the unit grid, the first shorting pin 112 may be integrally formed with the second shorting pin 132.

In the first embodiment, the first short pin 112 is illustrated as passing through the unit grid.

The first shorting pin 112 and the second shorting pin 132 may be formed through a via hole process.

The first shorting pin 112 and the second shorting pin 132 affect the current distribution of the first conductor layer 110 and the second conductor layer 130.

The first conductor layer 110 may improve antenna performance by strengthening the ground component by the first shorting pin 112, and the second conductor layer 130 may be connected to the second shorting pin 132. As a result, the function of coupling the rear radiation pattern forward can be enhanced.

In addition, the first conductor layer 110 forms a modified Planar Inverted-F Antenna (PIFA) structure and depends on factors such as bandwidth, return loss at resonance frequency, and impedance matching efficiency. The shape can be adjusted.

As described above, the antenna 100 according to the first embodiment using the planar PIFA structure has an advantage of easy deformation and processing.

In addition, the first conductor layer 110 and the second conductor layer 130 are operated in a coplanar waveguide (CPW) manner, and the current and energy radiated behind the first conductor layer 110 are controlled by the second conductive layer. The body layer 130 may be collected in front of the first conductor layer 110, and the energy flow may be adjusted to obtain an effect of improving gain.

Since the ground layer 150 has a larger effect on antenna performance, the ground layer 150 may have the same width as that of the first dielectric layer 120 and the second dielectric layer 140.

4 is a diagram schematically illustrating the shape of the surface current of the antenna 100 according to the first embodiment.

Referring to FIG. 4, the current is distributed evenly over the entire area of the first conductor layer 110, mainly around the slot S1, and the rear current is almost blocked by the second conductor layer 130. It can be seen.

In addition, the second shorting pin 132 connects the ground layer 150 and the second conductor layer 130 to strengthen the ground component, and thus a current signal radiated through the first conductor layer 110. It can be seen that the strength of.

5 is a diagram illustrating an electric field field of the antenna 100 according to the first embodiment.

Referring to FIG. 5, the electric field of the antenna 100 according to the first embodiment is measured in a form similar to the surface current, and it can be observed that the electric field energy is strongly formed toward the front of the first conductor 110. .

6 is a diagram schematically illustrating the shape of a radiation pattern of the antenna 100 according to the first embodiment.

The radiation pattern shown in FIG. 6 measures the antenna 100 according to the first embodiment and measures the signal source while sequentially moving angles θ and Φ in the respective axial directions from 0 to 90 degrees. In this case, it can be observed that the antenna gain in front of the first conductor 110 is increased.

The areas indicated on the radiation pattern show the difference in power gain.

For reference, the frequency efficiency at measurement is 0.7040 (reference is higher efficiency as it approaches 1), and the gain (dB) is 5.246 dB in the S parameter (S1.1; meaning that the input and output ports are the same). Was measured.

The general PIFA antenna does not have a concentrated radiation pattern as in the first embodiment, and the gain is only about 3 dBi.

However, the antenna 100 according to the first embodiment may improve the overall gain by more than 5dBi or more by 2dBi or more than the general PIFA antenna.

Although the first conductor part 110 according to the first embodiment has a “U” shaped slot S1, CPW feeding may be performed through various slot structures.

7 is a perspective view showing the structure of the antenna 200 according to the second embodiment, Figure 8 is a perspective view showing the structure of the antenna 300 according to the third embodiment, Figure 9 is a fourth embodiment It is a perspective view showing the structure of the antenna 400 according.

7 to 9, the antennas 200, 300, and 400 according to the second, third, and fourth embodiments may include a first conductor layer 210, 310, 410, and a first dielectric layer ( 220, 320, 420, second conductor layers 230, 330, 430, second dielectric layers 240, 340, 440, ground layers 250, 350, 450, chip elements 260, 360, 460, It comprises a connecting member (262, 362, 462).

The antenna 200, 300, 400 according to the second embodiment, the third embodiment and the fourth embodiment differs from the first embodiment described above in that the slots formed in the first conductor portions 210, 310, and 410 are different. It is in (S2, S3, S4) structure.

That is, the slot S2 according to the second embodiment is a one-shaped slot, and is formed along an elongated side of the first conductor portion 210, and the slot S3 according to the third embodiment has an "L" shape. Slot.

In addition, the slot S4 according to the fourth embodiment is a one-shaped slot and is formed along a short side of the first conductor portion 410.

As such, the slot structures of the first conductor parts 110, 210, 310, and 410 according to each embodiment may be modified to implement various power feeding methods.

In addition, if the structure and operation of the antennas 200, 300, and 400 according to the second, third, and fourth embodiments are similar to those of the first embodiment, repeated description thereof will be omitted.

For example, the antennas 200, 300, and 400 according to the second, third, and fourth embodiments are provided with the first short circuit pins 212, 312, and 412, as in the first embodiment. 1 The conductor layers 210, 310, and 410 are connected to the ground layers 250, 350, and 450.

Although not illustrated, the antennas 200, 300, and 400 according to the second, third, and fourth embodiments penetrate through the second dielectric layers 240, 340, and 440. And a second shorting pin connecting the second conductor layers 230, 330, and 430 to the ground layers 250, 350, and 450.

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 are not possible that are not illustrated above. 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 perspective view illustrating the structure of a second conductor layer according to the first embodiment;

3 is a side cross-sectional view of the antenna according to the first embodiment when cut based on the display line A-A 'of FIG. 1;

4 is a diagram schematically illustrating the shape of the surface current of the antenna according to the first embodiment.

5 is a diagram of measuring an electric field of an antenna according to the first embodiment;

6 is a diagram schematically illustrating the shape of a radiation pattern of an antenna according to the first embodiment.

7 is a perspective view showing the structure of the antenna according to the second embodiment;

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

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

Claims (10)

A slot formed first conductor layer; A first dielectric layer formed under the first conductor layer; And And a second conductor layer formed under the first dielectric layer and forming a lattice structure. The method of claim 1, A second dielectric layer formed under the second conductor layer; And And a ground layer formed under the second dielectric layer. The method of claim 1, wherein the second conductor layer is An antenna comprising a plurality of unit grids in the form of one or more of a circle, a polygon, and regularly arranged at predetermined intervals. The method of claim 2, And at least one first shorting pin formed through the first dielectric layer, the second conductor layer, and the second dielectric layer and electrically connecting the first conductor layer and the ground layer. The method of claim 2, And at least one second shorting pin formed through the second dielectric layer and electrically connecting the second conductor layer and the ground layer. The method of claim 1, And a chip device positioned in the slot and electrically connected to the first conductor layer. The method of claim 4 or 5, wherein the short circuit pin Antenna formed in the form of via hole. The method of claim 2, wherein at least one of the first dielectric layer and the second dielectric layer is An antenna comprising a FR4 substrate. The method of claim 4, wherein The second conductor layer includes a plurality of unit grids regularly arranged at predetermined intervals, The first short circuit pin passes through the unit grid or between the unit grids. The method of claim 1, wherein the slot is And at least one of a "U" shaped slot, a "L" shaped slot, and a "1" shaped slot formed along one side of the first conductor layer.

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