KR100922230B1 - Multilayer Antenna - Google Patents

Abstract

PURPOSE: A multilayer antenna increasing channel capacity and data speed are provided to secure feature enhancement effect in full band by relieve mutual interference of full band while keeping antenna characteristics without changing the band. CONSTITUTION: A multilayer antenna includes a plurality of antenna strips(30), an antenna plate(40), and an insulating layer. The plural antennas trips are connected with an individual feeding part and they are arranged to be adjacent with each other. The antenna plate includes a coupling stage and a connection part, and the coupling part is coupled with the plural antenna strips. The connection part makes the coupling stage connected with each other, and the antenna plate is separately placed with the antenna strip. The insulating layer is formed between the antenna strip and the antenna plate.

Description

Multilayer Antenna

The present invention relates to a multi-layered antenna that can improve communication performance by improving the performance of a plurality of closely arranged antenna elements by coupling to reduce the size and increase the gain.

In the wireless communication methods such as Wimax, 802.11x, or Long Term Evolution (LTE), which are gaining popularity as the next communication methods, various problems must be solved in order to provide the same or superior performance as wired voice and data communication. .

One of the techniques for reducing the difference between the wireless communication and the wired communication is the MIMO (Multiple-Input, Multiple-Output) method using a plurality of antennas. MIMO is an attractive new approach to solving wireless communication problems such as signal attenuation, increased interference and spectrum constraints.

MIMO uses multiple antennas to provide diversity of antennas, doubling data processing speed, simultaneously improving bandwidth range and reliability, and without consuming additional radio frequencies.

MIMO is an innovative multidimensional approach to sending and receiving two or more separate data streams over a single wireless channel, which allows the system to provide more than twice the data rate per channel. By allowing the simultaneous transmission of multiple data streams, MIMO multiplies wireless data capacity without the need for additional frequency spectrum.

The peak processing speed of the MIMO system can be as high as a multiple corresponding to the number of signal streams transmitted on the wireless channel. Since multiple signals are transmitted from each of the different radios and antennas, the MIMO signal is called a 'multidimensional' signal.

MIMO, which provides such an advantage, requires a plurality of antenna elements, and thus, a mobile communication terminal requires mounting a plurality of antennas in a relatively small space compared to a base station. Phenomenon occurs and the signal is distorted or canceled, resulting in a significant drop in reception sensitivity. That is, the flow of current induced between the plurality of antennas occurs to weaken the signal sensitivity, which causes a break in data communication, making it difficult to obtain a gain by applying the MIMO system.

In addition to the MIMO system, such a system using a plurality of antennas includes a tunable antenna system using a plurality of antennas set to different bands, a smart antenna system having a configuration similar to that of MIMO, and such a system. Appearing.

FIG. 1 illustrates a conventional example in which a plurality of antennas are configured in a single layer, and illustrates a case in which a monopole antenna is implemented by configuring a pair of symmetrical antenna strips 11 on a plane of a carrier 10.

Substantially, as illustrated, when the monopole antennas are arranged adjacent to each other in a symmetrical manner, one antenna signal is induced in the adjacent antenna to reduce antenna sensitivity, thereby reducing the length of the antenna and lowering communication performance.

For example, when the illustrated configuration is configured to operate in the 2.5 GHz band, the length of the antenna strip 11 is required about 30 mm. However, when the antenna strip is configured to have a length of 30 mm, the resonant frequency of the corresponding antenna is actually higher than 2.5 GHz, which shows the effect of reducing the actual antenna length. In other words, if an antenna operating in the 2.5 GHz band is required, the antenna length must be further extended.

Figure 2 shows the actual line characteristics of the antenna designed in the 2.5GHz band, it can be seen that the resonance occurs at a frequency higher than 2.5GHz as shown in the phenomenon that the length of the antenna is reduced.

Figure 3 shows an equivalent circuit of the antenna configured as shown in Figure 1, in the antenna consisting of two ports, as shown, one antenna signal can be induced to the adjacent antenna it can be seen that there is no means to prevent this have.

Therefore, when a plurality of antennas are configured in this way, when the antenna having a single layer structure is applied, the length of the antenna must be configured longer, and the antenna configuration space increases because the distance between the antennas must be sufficiently separated. In addition, the gain is also reduced by interference, resulting in lower channel capacity and data rate.

Recently, a new type of antenna configuration has been introduced to reduce interference between adjacently arranged antennas. For example, a technique such as adding a line that shorts the antennas between a plurality of antennas or adding a specific signal processing circuit is used. It is being applied experimentally. However, the method of directly shorting the antennas has a fatal problem of reducing the bandwidth by changing the band characteristics of the antenna, and the method of adding the signal processing circuit has a problem in that it is difficult to actually apply the additional configuration.

Accordingly, an object of the present invention is to provide a multi-layer antenna that can reduce the size of an antenna in a multiple antenna composed of a plurality of antenna elements in close proximity and block interference and noise between antennas to increase channel capacity and data rate. It is done.

In addition, an object of the present invention is to provide a multi-layered antenna that does not change the band to maintain the characteristics of the antenna while mitigating mutual interference for the entire band to ensure the effect of improving the characteristics for the entire band.

In addition, an object of the present invention is to provide a multi-layer antenna that can implement a tunable antenna by varying the antenna resonance point for each of a plurality of antenna ports by adjusting the position and arrangement of the multi-layer structure in applying the antenna plate. .

In order to achieve the above object, a multi-layer antenna according to an embodiment of the present invention and a plurality of antenna strips are arranged adjacent to each other while being connected to the individual feeder; A coupling part coupled to each of the plurality of antenna strips and a connection part connecting the coupling part to each other, and the antenna plate is spaced apart from the antenna strip.

An insulating layer may be further configured between the antenna strip and the antenna plate.

In addition, the multi-layer antenna according to an embodiment of the present invention comprises a first layer formed on the substrate and a plurality of antenna strips to secure the power supply and the electrical length of the antenna; A second layer spaced apart from the first layer; And a third layer spaced apart from the first layer by the second layer and having an antenna plate of a single conductor including a coupling portion coupled to each antenna strip of the first layer.

Multi-layer antenna according to an embodiment of the present invention has the effect of increasing the channel capacity and data rate by reducing the size of the antenna in the multiple antenna consisting of a plurality of antenna elements in close proximity, to block mutual interference and noise between the antennas .

The multilayer antenna according to the embodiment of the present invention has the effect of ensuring the characteristic improvement effect on the entire band by mitigating mutual interference on the entire band while maintaining the characteristics of the antenna by not changing the band.

Multi-layer antenna according to an embodiment of the present invention by adjusting the position and layout of the multi-layer structure in the application of the antenna plate can be variously adjusted the antenna resonance point for each of the plurality of antenna port has the effect that can implement a tunable antenna.

The multilayer antenna according to the embodiment of the present invention as described above will be described in detail with reference to the drawings.

The illustrated embodiments may be applied to an example of a MIMO antenna, a smart antenna having a similar structure, or the like, and may be applied as various antennas for reducing mutual interference between adjacent antennas.

4 is a perspective view of a multilayer antenna according to an exemplary embodiment of the present invention, in which a pair of antenna strips 30 are disposed on a carrier 20 in the same manner as the single-layer monopole antenna configuration shown in FIG. The antenna plate 40 is arrange | positioned at the upper layer which separated and spaced the air layer on the upper part.

5 is a cross-sectional view of a part of FIG. 4, in which an antenna strip 30 is disposed on a carrier 20, and a gap using dielectric insulating material or air for insulation thereon. It can be seen that the insulating layer 35 is formed, and the antenna plate 40 is formed on the upper portion thereof.

The separation configuration may be variously modified. In addition to the configuration as shown, the antenna strip 30 may be formed inside the carrier 20, or conversely, the antenna plate 40 may first be formed on the carrier 20. After forming, the antenna strip 30 may be spaced apart from each other. Also, both side ends of the antenna strip 30 and the antenna plate 40 may be spaced apart from each other on the same plane, and only portions connecting both side ends of the antenna plate 40 may be spaced apart from the antenna strip 30. The deformation is free. However, at least a part of the antenna strip 30 and the antenna plate 40 should have a multi-layered structure, and structural features of not being electrically connected to each other should be maintained.

As shown in FIGS. 4 and 5, when the multilayer antenna structure in which the antenna plate 40 is spaced apart from the single-layer antenna structure is formed, coupling by the antenna plate 40 spaced apart from the antenna strip 30 is performed. Due to the phenomenon, it is possible to block the antenna signal of one side from being induced by the adjacent antenna. Meanwhile, a capacitance component is formed between the antenna strip 30 and the antenna plate 40 to reduce the physical length of the antenna.

FIG. 6 shows the line characteristics when the length of the antenna strip shown in FIG. 4 is 30 mm. In case of a single-layer antenna, resonance is performed at about 2.57 GHz as in FIG. 2, but the antenna plate 40 is as shown in FIG. ), It can be seen that resonance occurs at about 2.3GHz. That is, the resonance point movement of about 200 MHz can be confirmed by the capacitance component between the antenna strip 30 and the antenna plate 40. This shows that the physical length of a monopole antenna, a dipole antenna, a Planar Inverted-F Antenna (PIFA), or a patch antenna mounted in a portable device can be reduced.

As a result, when the antenna is configured in a multilayer structure in which the antenna plate spaced apart from the insulation layer is applied to the single-layer antenna structure as shown in the exemplary configuration of FIGS. 4 and 5, the antenna strip length on the carrier is reduced, thereby reducing the carrier size. The volume of the entire antenna can be reduced.

FIG. 7 illustrates a schematic diagram and an equivalent circuit for explaining the operation principle of the multilayer antenna structure illustrated in FIGS. 4 to 5. First, a pair of antenna elements respectively fed by the antenna strip 30 are defined. An antenna plate 40 having spaced apart from the antenna strip 30 having both side ends disposed in parallel with the antenna strip 30 and connecting portions connecting the both ends to each other in a direction perpendicular to the antenna strip 30. Thus, the first antenna A1 and the second antenna A2 are operated. When considering this as a single antenna, the feeder of each antenna may be referred to as a first port and a second port.

The antenna strip 30 simultaneously feeds and radiates, and the antenna plate 40 simultaneously performs radiating and organic current canceling functions.

In the equivalent circuit configuration shown on the right, the capacitor and inductor pairs configured in parallel on the left and right sides mean portions of the first antenna A1 and the second antenna A2, which operate as an antenna by coupling, respectively, on top of each other. The configured resistor and capacitor (inside the circle) refer to a connection portion connecting both side ends (ie, a coupling portion) of the antenna plate 40.

Currents radiated from the first antenna A1 and the second antenna A2 are respectively reflected by a series-connected capacitor (inside the circle) corresponding to the antenna plate connection portion, and the currents induced by each other are canceled with each other by a symmetrical structure. do. That is, the series-connected capacitor prevents unwanted signals from neighboring antennas, and this circuit configuration is equivalent to a general noise canceling circuit used in an active antenna, so that the active performance of the terminal can be increased.

FIG. 8 shows an equivalent circuit of the coupling structure antenna. As shown in FIG. 8, the capacitor C1 connected in series with the power supply unit performs a current blocking function to perform an organic current blocking and a noise removing function. Since this configuration is applied to the equivalent circuit of the multilayer antenna according to the exemplary embodiment of the present invention as shown in FIG. 7, the multilayer antenna according to the exemplary embodiment has an organic current blocking function and a noise canceling function, thereby improving the active performance of the terminal. .

9 to 11 show configuration examples of the multilayer antenna according to the embodiments of the present invention.

FIG. 9 is a diagram in which the lengths of the adjacent sides of the antenna strip 31 and the antenna plate 41 are long, and the antenna strips 31 spaced apart from each other by a predetermined distance are disposed on the carrier 20 on the substrate 25. The antenna strip 30 is spaced apart from the antenna strip 31 and disposed above the antenna strip 31, and both ends (coupling portions) are disposed outside the antenna strip 31, and the connecting portion 50 connecting the both ends is the antenna strip. It is composed of the antenna plate 41 of the 'c' shape is disposed perpendicular to the (31). The antenna strip 31 and the antenna plate 41 may have various structures having curved surfaces along the structure of the carrier 20, and the antenna plate 41 may be modified in addition to the 'c' shape. Do.

The antenna strip 30 and the antenna plate 40 form a pair of symmetrical antenna parts. The antenna strip 30 is composed of a pair of strip electrodes, each of which is a feeding part of an independent antenna to which different signals are fed. It also works as a radiator at the same time. On the other hand, both ends of the antenna plate 40 in close proximity to the antenna strip 30 operate as antennas fed by coupling, respectively, and adjacent antenna induced signals by one end of the connecting portion 45 connecting the both ends at the same time. Is cut off and noise is removed.

FIG. 10 illustrates a case in which the antenna strip 32 and the antenna plate 42 are more three-dimensionally configured in a configuration in which the arrangement of the antenna strip and the antenna plate is modified. When such a structure is used, multiband characteristics may be exhibited. On the other hand, Figure 11 shows a simplified structure of the antenna strip 33 and the antenna plate 43, when using this structure can show a more effective band characteristics.

As illustrated in FIGS. 9 to 11, a multi-layered antenna structure including a first layer including an antenna strip, a second layer defined as a separation space, and a third layer defined as an antenna plate is various and three-dimensional (enclosing a carrier). Shape, or the first layer is formed on the three-dimensional carrier, etc.) and the third layer, the second layer, and the first layer may be sequentially disposed on the substrate by changing the arrangement.

On the other hand, the antenna line characteristics may vary due to the separation distance between the antenna plate and the antenna strip, the size of the coupling portion (both ends) of the antenna plate, the length of the adjacent portion of the antenna strip and the antenna plate, the distance between the antenna strip, and the structure of the antenna strip. As it can be adjusted, proper antenna strip and antenna plate placement is required.

In addition, the antenna strip included in the multi-layer antenna according to the present invention may be composed of a general built-in antenna structure such as monopole antenna, dipole antenna, PIFA or patch antenna.

FIG. 12 is a simplified circuit diagram illustrating a characteristic change of individual antennas according to the line characteristic adjustment. In the multilayer antenna including a plurality of antennas, as shown in FIG. In this case, the resonance point can be set differently for each antenna, and in this case, a tunable antenna using a switching antenna can be configured.

That is, since the capacitance and inductance vary according to the height and dielectric constant of the insulating layer and the structure of the antenna strip and the antenna plate for each antenna, it can be configured as the equivalent circuit shown in FIG. 13. The antenna can be configured. As a result, switching antennas having different band characteristics can be easily configured by adjusting the arrangement structure of the plurality of antennas, and since the signals are separated from each other, the antennas using the same band as MIMO or smart antennas can be used. It can improve performance.

14 and 15 illustrate an example of preventing interference by blocking a current induced in a port other than a port in which an antenna plate is induced by a flow of current induced between antennas in a multi-layer antenna using multiple ports.

FIG. 14 shows the flow of current induced in port 1 (P1), and the flow of current of one port induced in one coupling antenna is blocked by the capacitance component formed in each coupling antenna so as not to interfere with another port. It showed no. 15 similarly shows that the flow of current induced in port 2 (P2) is not induced to another port.

Therefore, in the case of configuring a plurality of antennas, applying a multi-layer antenna reduces interference between ports, removes noise, and improves antenna performance, and adjusts an arrangement structure of each layer to give independent characteristics for each antenna. In addition, the active performance of the terminal to which such an antenna is applied may be increased.

In addition, when the above-described configuration is used, not only an effect of extending the antenna length by the coupling effect can be obtained, but also it is possible to prevent a change in the band characteristics of the antenna while suppressing the interference between the antennas.

Recently, in order to suppress interference between adjacent antennas, a single-layer antenna structure, which directly connects a plurality of antennas or configures elements between antennas, has been introduced. However, since these structures directly connect antennas, there is a problem of reducing the bandwidth of an antenna. Will occur.

However, the configuration according to the embodiment of the present invention does not reduce the bandwidth defined by the antenna strip because the antenna plate is spaced apart from the antenna strip while configuring the antenna in a multi-layer structure, so that multiple antennas requiring even communication characteristics for a wide band are required. Optimal performance can be achieved by constructing a small area.

FIG. 16 shows the characteristics of a multi-layer MIMO antenna constructed in accordance with an embodiment of the present invention as an S parameter, in which two monopole antennas are configured to be symmetrical. Looking at the band characteristics of S11 and S22 representing the reflection characteristics of each of the antennas, it can be seen that the band of 2.5 GHz to 2.7 GHz is a use band of -10 dB or less. At this time, the graph of S21 for showing the mutual interference characteristics between the antennas shows excellent characteristics of -13 dB or less for the corresponding use band.

In general, when the monopole antenna is disposed in close proximity, the S21 reflection characteristic in the use band is less than -10dB, since the S21 reflection characteristic in the use band is 0dB or more, which means that there is little effect between the pair of antennas.

FIG. 17 illustrates S parameter characteristics of a multi-layer antenna configured as one of the embodiments of the present invention. S21 of the illustrated graph is shown in dB scale, and S11 and S22 represent the ratio of the voltage standing wave ratio (VSWR) (right side of the graph). Indicates.

As shown, S11 and S22 have a voltage standing wave ratio of 2.5 or less, and S21 exhibits a characteristic of -7 dB or less at 1.7 to 2.1 GHz, which shows little interference between antennas.

FIG. 18 shows the H plane pattern of the embodiment of FIG. 17, the first antenna having the left side and the second antenna having the right side, which are symmetrical without interference.

Therefore, in the embodiment of the present invention, in the multilayer antenna, the antenna characteristics can be adjusted and improved only by installing the antenna plate spaced apart from the antenna strip plane, and the individual characteristics of the plurality of antennas can be adjusted. In addition to reducing the length, mutual interference between antennas can be prevented without band loss.

In the above described and illustrated with respect to preferred embodiments according to the present invention. However, the present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art without departing from the gist of the present invention attached to the claims. .

1 is a view showing the configuration of a conventional single-layer monopole antenna

Figure 2 is a graph showing the line characteristics of a conventional monolayer monopole antenna.

3 is an equivalent circuit diagram of a conventional single layer monopole antenna.

4 is a perspective view of a multi-layer antenna according to an embodiment of the present invention.

5 is a cross-sectional view of a multi-layer antenna according to an embodiment of the present invention.

6 is a graph showing the line characteristics of a multi-layer antenna according to an embodiment of the present invention.

7 is an antenna structure and equivalent circuit of a multilayer antenna according to an embodiment of the present invention.

8 is an equivalent circuit of a coupling structure antenna;

9 to 11 are perspective views of a multilayer antenna according to embodiments of the present invention.

12 is a multi-port equivalent circuit of a multi-layer antenna according to an embodiment of the present invention.

FIG. 13 is a conceptual view illustrating characteristic variation of a multilayer antenna according to an exemplary embodiment of the present invention. FIG.

14 and 15 are equivalent circuits showing the organic current flow of the multilayer antenna according to the embodiment of the present invention.

16 is a graph showing S-parameter characteristics of a multilayer antenna according to the present invention.

17 is a graph showing S-parameter characteristics of a multilayer antenna according to the present invention.

18 is a graph illustrating a radiation pattern of the high isolation multiple antenna according to the embodiment of FIG. 17.

*** Description of the symbols for the main parts of the drawings ***

20: carrier 30: antenna strip

40: antenna plate 50: connection portion

Claims (14)

A plurality of antenna strips connected to the respective feeders and disposed adjacent to each other; An antenna plate having a coupling portion coupled to each of the plurality of antenna strips and a connecting portion connecting the coupling portions to each other, the antenna plate being spaced apart from the antenna strip; And an insulating layer formed between the antenna strip and the antenna plate. delete The multi-layer antenna of claim 1, wherein the antenna strip is configured on a plurality of surfaces of a three-dimensionally formed carrier. The multilayer antenna of claim 1, wherein the coupling part of the antenna plate is disposed to overlap at least one side with the antenna strip to be coupled. The multilayer antenna according to claim 1, wherein the arrangement of the antenna plate and the antenna strip is determined according to a band characteristic of each radiation region defined as a coupling portion of the antenna plate and an antenna strip coupled to the coupling portion. . The multilayer antenna according to claim 5, wherein the arrangement between the coupling portion of the antenna plate and the antenna strip is different for each radiation region defined by the coupling portion of the antenna plate and the antenna strip coupled with the coupling portion. The multilayer antenna according to claim 5, wherein an arrangement between the coupling portion of the antenna plate and the antenna strip is identical for each radiation region defined by the coupling portion of the antenna plate and the antenna strip coupled with the coupling portion. The method of claim 5, wherein the band characteristics of each radiation region defined by the coupling portion of the antenna plate and the antenna strip coupled with the coupling portion, the separation distance between the antenna plate and the antenna strip, the size of the coupling portion of the antenna plate, the antenna And the length of adjacent portions of the strip and antenna plate, the distance between the antenna strips, and the structure of the antenna strip. The multilayer antenna of claim 1, wherein the antenna strip has one of a monopole antenna, a dipole antenna, a Planar Inverted-F Antenna (PIFA), and a patch antenna structure. A first layer formed on the substrate, the first layer having a plurality of antenna strips for securing the electrical length of the power supply and the antenna; A second layer spaced apart from the first layer; And a third layer spaced apart from the first layer by the second layer and having an antenna plate of a single conductor including a coupling portion coupled to each antenna strip of the first layer. The multi-layer antenna of claim 10, wherein the second layer is formed of an insulator including air or a dielectric material, and determines a separation distance between the antenna strip of the first layer and the antenna plate of the third layer. . 12. The multi-layer antenna of claim 11, wherein the second layer has a different height for each radiation region defined by a coupling portion of the first layer antenna strip and the third layer antenna plate. The multi-layer antenna of claim 10, wherein the first layer comprises an antenna strip configured on a plurality of surfaces of the three-dimensional substrate. The multi-layer antenna according to claim 10, wherein the third layer is formed in a substrate region in which the first layer is formed.

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