KR101412135B1 - Horizontal polarized omni-directional antenna for MIMO - Google Patents

Abstract

The present invention relates to a horizontal polarization unidirectional antenna for MIMO, the horizontal polarization unidirectional antenna comprising: a first radiating element including a first signal terminal and a first ground terminal; A second radiating element disposed perpendicular to the first radiating element, the second radiating element including a second signal end and a second ground end; And a feeder for feeding a signal to the first radiating element and the second radiating element, wherein the feeder feeds a plurality of port signals to each signal terminal, and the plurality of port signals And have different phase characteristics.

Description

[0001] Horizontal polarized omni-directional antenna for MIMO [0002]

The present invention relates to a horizontal polarization unidirectional antenna for MIMO, and more particularly, it is possible to implement a plurality of independent antenna ports without increasing the number of antennas or increasing the number of polarization, To a horizontally polarized omnidirectional antenna.

In accordance with the development of wireless communication technology, MIMO (Multiple Input Multiple Output) technique which utilizes spatial scattering of radio waves is actively used in LTE (Long Term Evolution) called 4th generation mobile communication. The 3GPP Release 10 specification, released in 2010, supports up to 8 x 8 MIMO in LTE Advanced.

The MIMO technique is a technique for increasing the transmission rate by using a plurality of antennas for transmitting and receiving. To realize this, a plurality of independent antenna ports are required. 2 x 2 MIMO requires two independent antenna ports, and four and eight independent antenna ports for 4 x 4 and 8 x 8 MIMO, respectively. need.

Meanwhile, there are various techniques for forming a plurality of independent antenna ports. Typically, spatial diversity techniques, polarization diversity techniques, and the like are used for MIMO implementation.

First, a space diversity technique is a technique of forming a plurality of independent antenna ports by using a plurality of antennas spaced at a certain distance.

Next, a polarization diversity technique is a technique of forming a plurality of independent antenna ports by implementing polarizations orthogonal to each other in one antenna. That is, a technique of forming a plurality of independent antenna ports using polarization orthogonality.

However, in these conventional techniques, it is necessary to install a plurality of antennas in order to form a plurality of independent antenna ports, and it is necessary to implement a plurality of polarizations in one antenna without installing a plurality of antennas.

Therefore, there is a demand for a new concept MIMO antenna capable of forming a plurality of independent antenna ports without installing a plurality of antennas (space diversity) or implementing a plurality of polarized waves (polarization diversity).

The present invention is directed to forming a plurality of independent antenna ports using a single antenna and a single polarized wave. In particular, a plurality of antenna ports are formed by using only one horizontal polarization in one antenna.

According to an aspect of the present invention, there is provided a horizontal polarization uni-directional antenna for a MIMO system, including: a first radiating element including a first signal terminal and a first ground terminal; A second radiating element disposed perpendicular to the first radiating element, the second radiating element including a second signal end and a second ground end; And a feeder for feeding a signal to the first radiating element and the second radiating element, wherein the feeder feeds a plurality of port signals to each signal terminal, and the plurality of port signals And have different phase characteristics.

Here, the MIMO horizontal polarization non-directional antenna can form a plurality of antenna ports using only horizontal polarization.

The plurality of port signals may be an A port signal and a B port signal, and the power supply unit may be configured to 1) supply a signal of the A port to the first signal terminal and the second signal terminal, The phase of the signal fed to the second signal terminal by 90 degrees from the phase of the signal fed to the second signal terminal, 2) feeding the signal of the B port to the first signal terminal and the second signal terminal, The phase of the signal fed to the first signal terminal may be delayed by 90 degrees from the phase of the signal fed to the second signal terminal.

The plurality of port signals may be an A port signal and a B port signal, and the power supply unit may be configured to 1) supply a signal of the A port to the first signal terminal and the second signal terminal, To the first signal terminal and to the second signal terminal while the phase of the signal fed to the second signal terminal is delayed by 90 degrees from the phase of the signal fed to the second signal terminal, The phase of the signal fed to the first signal terminal can be advanced by 90 degrees from the phase of the signal fed to the second signal terminal.

In addition, the power supply unit includes a 90-degree hybrid circuit, and can generate two signals having a phase difference of 90 degrees with respect to each port signal, and then use it for power supply.

Also, the A port signal and the B port signal have the same irregular radiation pattern, but the direction of rotation of the electric field may be opposite to each other.

The first radiating element and the second radiating element may be dipole elements, or may be formed in the form of a turnstile antenna.

In addition, the first radiating element and the second radiating element may be formed of a radiating element having a slot at the center, and may form a cross-slot structure.

In addition, the slots may be formed in a vertical direction and may have a length of 0.5 to 1 wavelength.

The present invention can form a plurality of antenna ports without using a plurality of antennas or using a plurality of polarized waves. Specifically, the present invention can form a plurality of independent antenna ports even if only one antenna and one polarization are used, and MIMO can be implemented through these independent antenna ports.

In addition, the present invention can form a plurality of independent antenna ports using only one horizontal polarization uni-directional antenna. Specifically, the present invention can form two independent antenna ports using only one horizontal polarization uni-directional antenna and having the same omni (omnidirectional) radiation pattern but different phase characteristics from each other.

In addition, the present invention has the same coverage of two antenna ports, because two independent antenna ports formed through a single horizontal polarization uni-directional antenna have a same radiation pattern with only different phase characteristics. Therefore, the diversity effect for the MIMO implementation is constant regardless of the direction (incidence direction of the radio wave).

In addition, the present invention can form a horizontal polarization unidirectional antenna for MIMO by using radiating elements formed with slots in the vertical direction, and the horizontal size of the horizontal polarization unidirectional antenna can be reduced through such a structure.

FIG. 1 is a configuration diagram of a horizontal polarization unidirectional antenna for MIMO according to an embodiment of the present invention. Referring to FIG.
Fig. 2 is an exemplary diagram showing a hybrid circuit that may include a power supply section. Fig.
3 is a configuration diagram illustrating a horizontal polarization unidirectional antenna for MIMO according to another embodiment of the present invention.
Fig. 4 is a conceptual diagram showing a radiating element in which a slot having a dog-bone shape is formed.
5 is a graph showing the individual radial magnitudes of the first and second radiating elements, which may be included in a horizontal polarization uni-directional antenna according to the present invention.
FIG. 6 is a graph showing the radiation magnitudes of two port signals (port A and port B) radiated through a horizontal polarization unidirectional antenna according to the present invention.
7 is a graph showing the instantaneous value of the radiation pattern (magnitude) of the port A signal.
8 is a graph showing the instantaneous value of the radial pattern magnitude of the port B signal.
9 is a graph showing the phase values of the radiation patterns of the port A signal and the port B signal.
10 is a graph showing the rectangular coordinate system of FIG.

Hereinafter, a horizontal polarization uni-directional antenna for MIMO according to the present invention will be described in detail with reference to the accompanying drawings. The embodiments are provided so that those skilled in the art can easily understand the technical spirit of the present invention, and thus the present invention is not limited thereto. In addition, the matters described in the attached drawings may be different from those actually implemented by the schematic drawings to easily describe the embodiments of the present invention.

On the other hand, the expression " comprising " is intended to merely denote that such elements are present as an 'open expression', and should not be construed as excluding any additional elements.

Also, terms such as 'first, second, third' or A, B, C, D, etc. may be used to describe various components, but they are used to distinguish one component from another Purpose, and the attributes of the constituent elements are not limited by the terms.

The present invention relates to a horizontal polarization non-directional antenna. Here, the horizontal polarization non-directional antenna means an antenna having an omni-directional radiation pattern in which an electric field radiates a horizontal polarization that is horizontal to the ground and has an omni-directional radiation pattern with respect to the horizontal direction.

Such a horizontally polarized omnidirectional antenna can be configured in various forms within a range that is obvious to a person skilled in the art.

Hereinafter, a horizontal polarization unidirectional antenna for MIMO according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

The horizontal polarization unidirectional antenna for MIMO according to an exemplary embodiment of the present invention includes a first radiating element 100 including a first signal terminal and a first ground terminal, A second radiating element 200 including a second grounding terminal, and a feeding part 300 for feeding a signal to the first radiating element and the second radiating element.

Also, the first radiating element 100 and the second radiating element 200 may be arranged in the form of a turnstile antenna.

The first radiating element 100 is preferably configured in the form of a dipole and may include a first signal terminal 110 and a first ground terminal 120. The first signal terminal 110 is connected to the feeder 300 to transmit and receive a signal, and the first ground terminal 120 is connected to a ground plate or a ground bar to maintain a ground state.

The first radiating element 100 may be formed in the form of various conductors such as a conductor rod, a conductor plate, and a microstrip.

The second radiating element 200 is also configured in the form of a dipole and may include a second signal terminal 210 and a second ground terminal 220. The second signal terminal 210 is connected to the feeder 300 to transmit and receive a signal, and the second ground terminal 220 is connected to a ground plate or a ground bar to maintain a ground state.

The second radiating element 200 may be formed in the form of various conductors, such as a conductor rod, a conductor plate, and a microstrip.

Meanwhile, it is preferable that the first radiating element 100 and the second radiating element 200 are arranged horizontally on the ground. Therefore, both of the first radiating element 100 and the second radiating element 200 have horizontal polarization by this horizontal arrangement.

In addition, the first radiating element 100 and the second radiating element 200 are preferably arranged perpendicular to each other. Specifically, it is preferable that they are arranged perpendicular to each other as shown in Fig. 1, because a radial pattern of an irregular direction in the horizontal direction can be formed by such vertical arrangement.

The feeder 300 is configured to feed a signal to the first radiating element 100 and the second radiating element 200. Specifically, the feeder 300 feeds a signal to the first signal terminal 110 and the second signal terminal 210.

Here, the power feeder 300 may supply a plurality of port signals to the respective signal terminals. For example, the A port signal and the B port signal are supplied to the first signal terminal 110 , And the A port signal and the B port signal may be also supplied to the second signal terminal 210. (In other words, an A port signal is supplied to the first signal terminal 110 and the second signal terminal 210 and a B port signal is also supplied to the first signal terminal 110 and the second signal terminal 210, . ≪ / RTI >

In this case, the plurality of port signal signals preferably have different phase characteristics in relation to the first signal terminal 110 and the second signal terminal 210. For example, 1) the A port signal is fed to the first signal terminal 110 by 90 degrees in phase (0 degrees) and the second signal terminal 210 is phase-delayed by 90 degrees (- 90 degrees and the phase delay is negative), the B port signal is fed to the first signal terminal 110 in a phase (90 degrees) delayed by 90 degrees and the second signal terminal 210 (0 degrees) prior to the phase of the current I1. (2) the A port signal is fed to the first signal terminal 110 at a phase delay of 90 degrees (-90 degrees) and to the second signal terminal 210 at a phase 90 degrees ahead (0 The B port signal is fed to the first signal terminal 110 by 90 degrees in phase (0 degrees) and to the second signal terminal 210 by 90 degrees in phase (- (For reference, it is assumed that phase comparison is relatively performed between the first signal terminal 110 and the second signal terminal 210. For example, The fact that a signal 90 degrees ahead in phase is fed to the 1 signal terminal 110 means that a signal 90 degrees ahead of the phase of the signal fed to the second signal terminal 210 is fed. The fact that a signal delayed by 90 degrees in phase is fed to the signal terminal 210 means that a 90 degree delay in comparison with a phase of a signal fed to the first signal terminal 110 It means that the signal is the power supply.)

The difference in the phase characteristics is that the radiation pattern of the A port signal and the radiation pattern of the B port signal can be separated (independent) from each other through a power supply system having different phase characteristics. Specifically, both the radiation pattern of the A port signal and the radiation pattern of the B port signal are formed in the same irregular radiation pattern by the above-mentioned power feeding method, but the electric field directions are formed in different states with time. Therefore, the A port and the B port are distinguished from each other and can be independent (strictly speaking, a correlation or less correlation) due to the time difference in the electric field direction.

Meanwhile, the power feeder 300 may include a 90 degree hybrid circuit. Specifically, the 90-degree hybrid circuit 310 shown in FIG. 2 may be included.

As described above, the feeder 300 needs to generate two signals having a phase difference of 90 degrees with respect to each of the port signals (A port signal and B port signal), and then use them for power supply. The 90 degree hybrid circuit 310), these signals can be easily generated and used for power supply.

Referring to FIGS. 1 and 2, an A port signal and a B port signal are input to two input terminals of a 90 degree hybrid circuit 310. 1) The A port signal is distributed through the 90-degree hybrid circuit 310 to the A port signal (-90) whose phase is relatively delayed by 90 degrees relative to the A port signal (0 degree) preceding the phase relatively by 90 degrees The A port signal (0 degree) preceding the phase by 90 degrees is fed to the first signal terminal 110 and the A port signal (-90 degree) whose phase is delayed by 90 degrees is fed to the second signal terminal 210 do. 2) Also, the B port signal is similarly transmitted through the 90-degree hybrid circuit 310 to the B port signal (-90) whose phase is relatively delayed by 90 degrees relative to the B port signal (0 degree) The B port signal 0 whose phase is 90 degrees ahead is supplied to the second signal terminal 210 and the B port signal 90 whose phase is delayed by 90 degrees is supplied to the first signal terminal 110 Power is supplied. Therefore, through the 90 degree hybrid circuit 310, the A port signal and the B port signal can be supplied with different phase characteristics.

As described above, according to the present invention, a plurality of port signals (for example, A port and B port) can be made independent from each other by using one horizontal polarization non-directional antenna. Therefore, the present invention can implement a MIMO environment without adding an antenna or adding polarization.

Hereinafter, a horizontal polarization unidirectional antenna for MIMO according to another embodiment of the present invention will be described with reference to FIG. 3 to FIG.

The horizontal polarization uni-directional antenna for MIMO according to another embodiment of the present invention may include a radiating element in which slots are formed in the center of the first radiating element 400 and the second radiating element 500.

In addition, the first radiating element 400 and the second radiating element 500 may be coupled to each other in a state of being perpendicular to each other as shown in FIG. 3, so that a cross-slot structure can be formed have.

The slots formed in the first radiating element 400 and the second radiating element 500 are preferably formed in a vertical direction and are formed to have a length of 0.5 to 1 wavelength. In addition, the shape of the slot may be formed in a dog-bone shape as shown in FIG. 4 in order to improve impedance matching.

The horizontal polarization unidirectional antenna for MIMO according to another embodiment of the present invention is different from the horizontal polarization unidirectional antenna except for a structural difference in which the first radiating element 400 and the second radiating element 500 are formed in a cross- , The present invention described above has substantially the same characteristics as the horizontal polarization antenna for MIMO according to an embodiment.

For example, the MIMO horizontal polarization unidirectional antenna according to another embodiment of the present invention includes a first signal terminal 410, a first ground terminal 420, a second signal terminal 510, and a second ground terminal 520 And includes a power feeder 300 having the same features as those of the above embodiment.

Therefore, as described above, the MIMO horizontal polarization non-directional antenna according to another embodiment of the present invention can form a plurality of antenna ports (e.g., A port and B port) independent of each other under a single antenna and a single polarization (horizontal polarization) .

5 to 10, an embodiment in which two independent antenna ports are formed in one horizontal polarization uni-directional antenna will be described in detail.

It is assumed that the embodiment to be discussed below is as follows.

1) First, the forward direction of the power supply is assumed to be the X-axis and Y-axis directions shown in Figs. 1 and 3.

2) Also, the observer's angle is defined as counterclockwise from the X axis to the Y axis.

3) In addition, the signal of the port A is supplied to the first radiating element (100, 400, y-axis direction) at a relatively high 90 degrees relative to the first radiating element (0, Is assumed to be fed with a relatively 90 degree delay (-90 degree).

4) Further, the signal of the port B is supplied to the first radiating element (100, 400, y-axis direction) with a relative delay of 90 degrees (-90 degrees), and the second radiating element ) Is assumed to be fed to a state that is relatively 90 degrees ahead (0 degrees).

Referring to FIG. 5, the radial patterns of the first radiating element 100, 400, the y-axis direction and the second radiating element 200, 500, x-axis direction can be confirmed.

5, the radiation pattern formed by the first radiating element lying in the y-axis direction can be confirmed. Referring to the lower graph of FIG. 5, the second radiating element located in the x- Can be confirmed.

The port signals (A port and B port) are fed to the first radiating element (100, 400, y axis direction) and the second radiating element (200, 500, x axis direction) with a phase difference of 90 degrees , And the radiation patterns of the respective port signals (A port and B port) are formed in an omni-directional pattern as shown in Fig.

However, since the A port signal and the B port signal are fed with different phase characteristics, the direction of rotation of the electric field is opposite to each other.

Specifically, in the case of the A-port signal whose phase is 90 degrees faster than the phase of the second radiating element (200, 500, x-axis direction), the phase of the first radiating element As shown in the upper graph of FIG. 6, in a clockwise direction. Further, in the case of the B port signal in which the phase of the first radiating element (100, 400, y axis direction) is delayed by 90 degrees from the phase of the second radiating element (200, 500, x axis direction) As shown in the lower graph of FIG. 6, in a counterclockwise direction. (The arrows in the drawing indicate the direction of the electric field, and the numbers in the vicinity of the arrow indicate the time order).

Therefore, the A port and the B port can be distinguished from each other and can be independent (strictly speaking, have a correlation or less correlation) due to the difference in the electric field direction.

Referring to FIG. 7, the radiation pattern of the A-port signal can be checked instantaneously. Also, referring to FIG. 8, the radiation pattern of the B port signal can be checked instantaneously. (For reference, the arrows shown in the figure represent the direction of the electric field, and w t is the angular frequency and t is the time).

On the other hand, the phase of the radiation pattern of the A port signal is observed as shown in Table 1 below.

Viewpoint
(Degree) 0 45 90 135 180 225 270 315 Phase angle
(Degree) 0 315 270 225 180 135 90 45

Referring to the upper graph of FIG. 9, the phase of the radiation pattern of the A port signal can be observed.

Next, the phase of the radiation pattern of the B port signal is observed as shown in Table 2 below.

Viewpoint
(Degree) 0 45 90 135 180 225 270 315 Phase angle
(Degree) 90 135 180 225 270 315 0 45

Referring to the lower graph of FIG. 9, the phase of the radiation pattern of the B port signal can be examined.

Referring to Table 1, Table 2 and FIG. 9, it can be seen that the phase of the port A and the phase of the port B increase in opposite directions. Therefore, the two radiation patterns can be distinguished from each other by the difference in the phase characteristics, and a plurality of antenna ports can be formed through the two radiation patterns.

10 is a graph obtained by converting the graph of FIG. 9 into a rectangular coordinate system.

Referring to FIG. 10, it can be seen that the two graphs (the phase change of the A port and the phase change of the B port) show a straight line and have an opposite slope.

Therefore, when a signal arrives from various directions due to scattering as in the MIMO environment, the correlation between signals of the respective ports becomes smaller, so that the MIMO operation can be performed (a plurality of independent antenna ports can be formed).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, , Changes and additions should be considered to fall within the scope of the claims of this patent.

100: first radiating element 200: second radiating element
110: first signal stage 120: first ground stage
210: second signal stage 220: second ground stage
300: feeding part 310: 90 degree hybrid circuit
400: first radiating element 500: second radiating element
410: first signal stage 420: first ground stage
510: second signal stage 520: second ground stage

Claims (9)

In a horizontally polarized omnidirectional antenna,
A first radiating element including a first signal terminal and a first ground terminal;
A second radiating element disposed perpendicular to the first radiating element, the second radiating element including a second signal end and a second ground end; And
A feeder for feeding a signal to the first radiating element and the second radiating element;
, ≪ / RTI &
The power supply unit supplies a plurality of port signals to the respective signal terminals,
The plurality of port signals including an A port signal and a B port signal,
Wherein the A port signal and the B port signal have different phase characteristics at different signal ends.
The method according to claim 1,
A horizontal polarization unidirectional antenna for MIMO, wherein a plurality of antenna ports are formed using only horizontal polarization.
The method according to claim 1,
Wherein the plurality of port signals include an A port signal and a B port signal,
Wherein the power feeding unit feeds the signal of the port A to the first signal terminal and the second signal terminal, wherein the phase of the signal fed to the first signal terminal is 90 degrees As a result,
Wherein the power feeding unit feeds the signal of the port B to the first signal terminal and the second signal terminal and supplies the phase of the signal fed to the first signal terminal to the phase of the signal fed to the second signal terminal by 90 degrees Wherein the first antenna and the second antenna are spaced apart from each other by a predetermined distance.
The method according to claim 1,
Wherein the plurality of port signals include an A port signal and a B port signal,
Wherein the power feeding unit feeds the signal of the port A to the first signal terminal and the second signal terminal, wherein the phase of the signal fed to the first signal terminal is 90 degrees ≪ / RTI >
Wherein the power feeding unit feeds the signal of the port B to the first signal terminal and the second signal terminal and supplies the phase of the signal fed to the first signal terminal to the phase of the signal fed to the second signal terminal by 90 degrees Wherein the first antenna and the second antenna are spaced apart from each other.
The method according to claim 3 or 4,
Wherein the power feeder includes a 90-degree hybrid circuit, and generates two signals having a phase difference of 90 degrees with respect to each port signal, and then uses the generated signals for power feeding.
The method according to claim 3 or 4,
Wherein the A port signal and the B port signal have the same non-directed radiation pattern, but the electric field rotation directions are opposite to each other.
The method according to claim 1,
Wherein the first radiating element and the second radiating element are dipole elements,
Wherein the antenna is formed in the form of a turnstile antenna. ≪ RTI ID = 0.0 > 21. < / RTI >
The method according to claim 1,
Wherein the first radiating element and the second radiating element are radiating elements having slots formed at the center thereof to form a cross-slot structure.
9. The method of claim 8,
The slot
And is formed in a vertical direction and has a length of 0.5 to 1 wavelength.

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