WO2011046398A2

WO2011046398A2 - Antenna which includes choke member surrounding radiation element and distanced from reflective plate

Info

Publication number: WO2011046398A2
Application number: PCT/KR2010/007100
Authority: WO
Inventors: 일나르바타로브; 박철근; 백승철; 정민석; 오정근
Original assignee: 주식회사 에이스테크놀로지
Priority date: 2009-10-16
Filing date: 2010-10-15
Publication date: 2011-04-21
Also published as: KR101094510B1; KR20110041785A; WO2011046398A3

Abstract

Disclosed is an antenna having a structure in which a choke member surrounds a radiation element in a state separated from a reflective plate to improve a beam pointing error. The antenna comprises: the reflective plate; at least one radiation element arranged on the reflective plate; and the conductive choke member arranged around the radiation element. The choke member is arranged at a predetermined distance from the reflective plate.

Description

An antenna in which the choke member surrounding the radiation element is arranged spaced apart from the reflector

The present invention relates to an antenna implemented to surround a radiating element with a choke member spaced apart from a reflecting plate to improve beam pointing error.

The antenna has a radiation pattern for transmitting and receiving an RF signal (Radio Frequency), and generally has a structure shown in FIG. 1 below.

FIG. 1 is a diagram illustrating a structure of a general antenna, and FIG. 2 is a diagram illustrating a beam pointing error according to a change of an inclination angle in the antenna of FIG. 1.

Referring to FIG. 1, the antenna includes a reflector plate 100 and a plurality of radiation elements 102 arranged on the reflector plate 100.

When a predetermined power is supplied to the radiation elements 102, the radiation elements 102 output a radiation pattern in a specific direction, for example ± 45 ° polarizations.

However, for example, in the case of a base station antenna, it is often necessary to change the direction of the radiation pattern in order to transmit and receive a desired RF signal, that is, when the tilt angle Tilt of the antenna is changed.

Hereinafter, the characteristic change of the antenna when the inclination angle is changed in the antenna will be described.

When the inclination angle of the beam (radiation pattern) radiated from the radiation elements is changed to, for example, -15 ° as shown in FIG. 2, the beam pointing ideally the center of the radiation pattern 200 is formed along the Θ axis It should move along the line (Beam Pointing Line) 202. That is, when the tilt of the beam is changed by -15 °, ideally the center of the radiation pattern 204 should be located at the beam pointing line 202. Here, the beam pointing line 202 means a path in which the center of the radiation pattern 200 is moved when the inclination angles of the beams emitted from the radiation elements are changed.

In practice, however, when the inclination angle of the beam radiated from the radiation elements included in the antenna is changed, the center of the radiation pattern 200 does not move along the beam pointing line 202 but along the new beam pointing line 208. Move. That is, when the inclination angle of the beam radiated from the radiation element is changed by -15 °, the center of the radiation pattern 206 that is actually generated is positioned at the beam pointing line 208. Here, a value (eg, A) between the center of the radiation pattern 206 positioned on the beam pointing line 208 and the Θ axis is defined as a beam pointing error.

The beam pointing error is caused by the influence of an element inside or around the antenna (for example, a reflector), and in particular, as the inclination angle of the beam radiated from the radiation elements increases as shown in FIG. 2. do.

If the beam pointing error is outside the allowable range, the radiation pattern radiated from the radiation elements is not radiated in the desired direction. That is, it is difficult to control the direction of the radiation pattern output from the radiation elements.

It is an object of the present invention to provide an antenna that improves beam pointing error, beam width, and the like.

In order to achieve the object as described above, the antenna according to an embodiment of the present invention includes a reflector; At least one radiation element arranged on the reflector; And a conductive choke member arranged around the radiation element. Here, the choke members are arranged spaced apart from the reflecting plate by a predetermined distance.

The choke member is formed to surround the radiation element, and the radiation element has a circular shape.

The choke member includes a first sub choke member, a second sub choke member, a third sub choke member, and a fourth sub choke member to implement a rectangular shape. Here, the distance between the first sub choke member and the radiation element, the distance between the second sub choke member and the radiation element, the distance between the third sub choke member and the radiation element and the fourth sub choke member And at least one of the distances between the radiation elements has a length different from the other distances.

The reflector plate is a base member; And vertical members bent vertically from the base member and formed on both sides of the base member. Here, the first sub choke member and the third sub choke member face the vertical member, and the distance between the first sub choke member and the vertical member and the distance between the third sub choke member and the vertical member are The same is true, and the distance between the second sub choke member and the radiation element and the distance between the fourth sub choke member and the radiation element are different.

The first sub choke member and the third sub choke member are spaced apart from the vertical member.

A slot is formed in a lower end of at least one of the sub choke members, and the radiation element includes a plurality of radiating members, and a slot is formed in at least one of the radiating members.

The choke member further includes connecting portions for connecting between neighboring sub choke members.

Antenna according to another embodiment of the present invention is a reflector; A radiation element arranged on the reflector; And a conductive choke member surrounding the radiation element and having a first sub choke member, a second sub choke member, a third sub choke member and a fourth sub choke member. Here, the distance between the first sub choke member and the radiation element, the distance between the second sub choke member and the radiation element, the distance between the third sub choke member and the radiation element and the fourth sub choke member And at least one of the distances between the radiation elements has a length different from the other distances.

The choke members are arranged spaced apart from the reflecting plate.

The radiation element has a circular shape, a slot is formed in at least one of the first sub choke member or the fourth sub choke member, and a slot is formed in a portion of the radiation element.

Antenna according to another embodiment of the present invention is a reflector; A plurality of radiation elements arranged on the reflector; And a plurality of conductive choke members surrounding each of the radiating elements to satisfy the beam pointing error tolerance at a specific range of inclination angles.

At least one of the choke members is spaced apart from the reflecting plate, and an inclination angle satisfying the beam pointing error tolerance range is 0 ° to -15 °.

At least one of the choke members includes a conductive choke member having a first sub choke member, a second sub choke member, a third sub choke member and a fourth sub choke member, wherein the first sub choke member and the radiation element At least one of the distance between the second sub choke member and the radiation element, the distance between the third sub choke member and the radiation element, and the distance between the fourth sub choke member and the radiation element is different Have a different length than the distances.

In the antenna according to the present invention, the choke member spaced apart from the reflecting plate is implemented to surround the radiation element, and in particular, a slot is formed in at least one of the sub choke members included in the choke member. As a result, the beam pointing error of the antenna is improved, the cross polarization ratio (CPR) characteristic can be maintained high in the low frequency band and the high frequency band, and the beam width of the antenna can be kept wide.

In addition, since the choke member is coupled to the reflector using a plastic support, the choke member may be easily assembled at the antenna, and the choke member may be easily changed and installed if necessary.

In addition, since the choke member surrounds the radiation element and the choke member is coupled to the reflector through a plastic support, the distortion of the reflector can be reduced even if the length of the reflector is increased, and even if vibration, shock, etc. are applied, Mechanical stability can be ensured.

1 is a diagram illustrating a structure of a general antenna.

FIG. 2 is a diagram illustrating a beam pointing error according to a change of an inclination angle in the antenna of FIG. 1.

3 is a perspective view illustrating an antenna according to a first embodiment of the present invention.

4 is a diagram illustrating a detailed configuration of the radiation element and the choke member in the antenna according to an embodiment of the present invention.

FIG. 5 is a diagram schematically showing the structure of the antenna when the choke member is directly connected to the reflecting plate and when it is spaced apart from the reflecting plate.

FIG. 6 is a diagram illustrating CPR characteristics when the inclination angle is 0 ° in the antenna of FIG. 5.

FIG. 7 is a diagram illustrating CPR characteristics when the tilt angle of the antenna of FIG. 5 is −7 °.

FIG. 8 is a diagram illustrating beam pointing error characteristics in the antenna of FIG. 5.

9 is a perspective view showing the structure of an antenna according to a second embodiment of the present invention.

FIG. 10 is a diagram illustrating an electromagnetic field distribution when the choke member has no slot and an electromagnetic field distribution when the choke member has a slot.

FIG. 11 is a view illustrating beam width characteristic change in the antenna of FIG. 10.

FIG. 12 is a diagram illustrating a return loss characteristic of the antenna of FIG. 9.

FIG. 13 is a diagram illustrating isolation characteristics in the antenna of FIG. 9.

FIG. 14 is a diagram illustrating a beam pointing error characteristic of + 45 ° polarization in the antenna of FIG. 9.

FIG. 15 illustrates beam pointing error characteristics of -45 ° polarization in the antenna of FIG. 9.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, the antenna of the present embodiment is, for example, a base station antenna, which includes a reflector plate 300, at least one radiation element 302, and at least one choke member 304.

The reflector 300 is made of, for example, a conductor and may serve as a reflector and a ground.

According to one embodiment of the present invention, the reflector 300 includes a base member 310, a first vertical member 312 and a second vertical member 314.

The

vertical members

312 and 314 extend in length from both sides of the base member 310 in a direction perpendicular to the base member 310. These

vertical members

312 and 314 may affect the front and rear ratio and the beam width of the antenna.

The choke member 304 surrounds the radiation element 302 to improve beam pointing error as described below.

According to an embodiment of the present invention, the plurality of radiation elements 302 are sequentially arranged in the longitudinal direction on the reflector plate 300, and each of the radiation elements 302 is surrounded by the choke members 304. do.

According to another embodiment of the present invention, the choke members 304 are arranged spaced apart from the reflector plate 300. Specifically, the choke member 304 is spaced apart from the base member 310 as well as from the

vertical members

312 and 314.

According to another embodiment of the present invention, at least one of the distances between the sub choke members constituting the choke member 304 and the corresponding radiation element may be implemented to have a different length from the other distances.

In short, the antenna of the present invention is implemented to surround the radiation element 302 with the choke member 304 spaced apart from the reflector plate 300 to improve beam pointing error.

In the above, although the radiation element 302 is shown as having a circular shape, it may have a variety of shapes, such as a rectangular shape.

In addition, although the sub choke members constituting the choke member 304 are all connected to each other in FIG. 3, the sub choke members may be connected to the radiation element 302 with some of the sub choke members separated. It can be implemented to enclose.

According to another embodiment of the present invention, the choke member 304 may be implemented so as to surround only part of the radiation element 302 without completely surrounding it. However, in consideration of beam width improvement and the like, as described below, it is preferable that the choke member 304 completely surrounds the radiation element 302 as shown in FIG. 3.

Hereinafter, the detailed structure of the radiation element 302 and the choke member 304 of the present invention will be described.

4 is a diagram illustrating a detailed configuration of the radiation element and the choke member in the antenna according to an embodiment of the present invention. However, only one radiation element 302 and the corresponding choke member 304 are shown for convenience of description. Here, all of the choke members 304 may have the structure shown in FIG. 4, but only some of them may have the structure shown in FIG. 4.

Referring to FIG. 4A, the radiation element 302 includes a power supply unit 400 and radiation members 402.

The power supply unit 400 is a point at which predetermined power is input from the external power supply unit, and the power input to the power supply unit 400 is supplied to the radiation members 402. As a result, a predetermined radiation pattern is output from the radiation members 402.

The radiating members 402 are, for example, dipole members, and may all have the same structure. Of course, some of the radiating members 402 may have other structures, and for example, slots may be formed only in some of the radiating members 402 as described below.

The choke member 304 is implemented to surround the radiation element 302 as shown in Fig. 4A. Here, the choke member 304 may have a rectangular shape, for example, the first sub choke member 410, the second sub choke member 412, the third sub choke member 414, and the fourth sub choke member. 416.

According to an embodiment of the present disclosure, the choke member 304 may be spaced apart from the base member 310 of the reflector 300 by a predetermined distance and spaced apart from the

vertical members

312 and 314 by a predetermined distance. . In particular, in order to prevent the passive intermodulation distortion (PIMD), the choke member 304 is not directly connected to the reflector 300, as shown in FIG. 430 is coupled to the reflector plate 300. However, although the structure in which the choke member 304 is connected to the

vertical members

312 and 314 through another plastic support is not illustrated in FIG. 4B, the plastic support may move the choke member 304 to the vertical members 312. And 314).

According to another embodiment of the present invention, the distance between the first sub choke member 410 and the radiation element 302, the distance between the second sub choke member 412 and the radiation element 302, and the third sub choke member At least one of the distance between 414 and the radiation element 302 and the distance between the fourth sub choke member 416 and the radiation element 302 may have a different length.

For example, while the distance between the first sub choke member 410 and the radiation element 302 and the distance between the third sub choke member 414 and the radiation element 302 are the same, the second sub choke member 412 And the distance between the radiation element 302 and the fourth sub choke member 416 and the radiation element 302 may be different. As such, setting the distance between the second sub choke member 412 and the radiation element 302 different from the distance between the fourth sub choke member 416 and the radiation element 302 may result in beam pointing when adjusting the inclination angle of the antenna. To reduce the error.

Specifically, when the inclination angle of the antenna of the present invention is to be implemented to be variable between 0 ° and -15 °, the second sub choke member 412 and the radiation may be radiated so that the beam pointing error hardly occurs at about -7 °. The distance between the elements 302 may be set differently from the distance between the fourth sub choke member 416 and the radiation element 302. Here, the beam pointing error may be greater than when the tilt angle of the antenna is 0 ° and −15 °, but when the tilt angle is −7 °, the beam pointing error may have a value within an acceptable range.

According to another embodiment of the present invention, the distance between the first sub choke member 410 and the first vertical member 312 of the reflecting plate 300, the choke member 304 neighboring the second sub choke member 412. ), At least one of the distance between the third sub choke member 414 and the second vertical member 314 and the distance between the fourth sub choke member 416 and the neighboring choke member 304 has a different length. It can have However, in consideration of various features of the antenna, the distance between the first sub choke member 410 and the first vertical member 312 of the reflector 300 is between the third sub choke member 414 and the second vertical member 314. It is preferable to set equal to the distance of.

According to another embodiment of the present invention, the first sub choke member 410 and the third sub choke member 414 are easily coupled with the

vertical members

312 and 314 of the reflector 300 through the plastic support. Coupling

auxiliary members

418 and 420 may be further formed to allow. Here, the coupling

auxiliary members

418 and 420 may be disposed closely with the

vertical members

312 and 314, and thus the plastic support may not be easily seen from the outside, which may be more advantageous for aesthetics.

FIG. 5 is a diagram schematically illustrating the structure of an antenna when the choke member is directly connected to the reflector and when the choke member is spaced apart from the reflector. FIG. 6 is a view illustrating CPR characteristics when the inclination angle is 0 ° in the antenna of FIG. 5. to be. FIG. 7 is a diagram illustrating a CPR characteristic at an inclination angle of −7 ° in the antenna of FIG. 5, and FIG. 8 is a diagram illustrating beam pointing error characteristics in the antenna of FIG. 5.

As shown in FIG. 5 (A), a first antenna in which the choke member is directly connected to the reflector and a second antenna in which the choke member 304 is arranged spaced apart from the reflector 300 as shown in FIG. In the following, various characteristics of the antennas will be described.

First, let's look at the CPR characteristics at the inclination angle of 0 °.

Referring to FIG. 6, the CPR characteristic curve 600 of the first antenna in which the choke member is directly connected to the reflector is lowered toward the high frequency band. That is, the phenomenon in which the CPR characteristic of the first antenna is degraded in the high frequency band can be confirmed.

On the other hand, the CPR characteristic curve 602 of the second antenna, in which the choke member 304 is arranged spaced apart from the reflecting plate 300, is higher than the CPR characteristic curve 600 of the first antenna as a whole, especially in the high frequency band. . That is, it can be seen that the CPR characteristics of the second antenna are generally superior to the CPR characteristics of the first antenna, and are significantly improved, particularly in the high frequency band.

In other words, it can be seen that the separation of the choke member 304 without directly connecting the reflective plate 300 to the CPR characteristics is better. This is because neighboring choke members 304 form a wall to prevent polarization output from the radiation element 302 from affecting the neighboring radiation element 302.

Next, we will look at the CPR characteristics at the inclination angle of -7 °.

Although not illustrated in the case of the first antenna in which the choke member is directly connected to the reflector, the CPR characteristic is lowered as the inclination angle of the first antenna increases. Accordingly, the first antenna is suitable for use in fixed antennas but not for variable antennas having varying inclination angles.

On the other hand, in the case of the second antenna in which the choke member 304 is arranged to be spaced apart from the reflector plate 300, the choke member 304 may be used in both the fixed antenna and the variable antenna because it maintains excellent CPR characteristics as well as the fixed antenna. Specifically, the second antenna may be used by moving the choke member 304 from the center of the radiation element 302 at a distance having an optimal CPR characteristic when the inclination angle range to be used is determined. That is, the second antenna may maintain some excellent CPR characteristics by setting some of the distances between the

sub choke members

410, 412, 414, and 416 from the radiating element 302 to have different lengths.

For example, the CPR characteristic curve 700 when the choke member 304 was moved 0 mm from the center of the radiation element 302 at -7 °, the CPR

characteristic curve

702 and 10 mm movement when 7 mm moved. Referring to the CPR characteristic curve 704, the CPR characteristic is excellent when the choke member 304 is moved 10 mm from the center of the radiation element 302 as shown in FIG. 7.

Accordingly, the choke member 304 may be moved by 10 mm from the center of the radiation element 302 in the second antenna. However, although such a setting may slightly deteriorate the CPR characteristics, for example, at inclination angles of 0 ° and -15 °, this difference is likely to have a value within an acceptable range. That is, when the CPR characteristics are adjusted based on the inclination angle of −7 °, excellent CPR characteristics may be maintained at the inclination angles of 0 ° to −15 °.

Next, we will look at the beam pointing error characteristics.

Referring to FIG. 8, the beam pointing error characteristic curve 800 of the first antenna in which the choke member is directly connected to the reflector is kept low in the low frequency band but considerably high in the high frequency band. That is, it can be seen that the beam pointing error of the first antenna is significantly reduced in the high frequency band.

On the other hand, the beam pointing error characteristic curve 802 of the second antenna, in which the choke member 304 is arranged spaced apart from the reflecting plate 300, is kept lower than that of the first antenna as a whole, especially in the high frequency band. have. That is, it can be seen that the beam pointing error characteristic of the second antenna is generally better than the beam pointing error characteristic of the first antenna, and in particular, is significantly improved than that of the first antenna in the high frequency band.

In other words, it can be seen that the separation of the choke member 304 without directly connecting the reflective plate 300 has better beam pointing error characteristics.

6 to 8, it can be seen that the antenna in which the choke member 304 is spaced apart from the reflecting plate 300 is excellent in various characteristics.

Referring to FIG. 9, the antenna of this embodiment includes a reflector plate 900, at least one radiation element 902 and at least one choke member 904.

Since the remaining components except for the choke member 904 are the same as in the first embodiment, the description of the same components will be omitted below.

Radiating element 902 includes, for example, four radiating members, although not shown to improve the half power angle (HPA) or half power beam width (HPBW). At least one of the slots may be formed.

The choke member 904 has a rectangular shape, for example, and includes a first sub choke member 910, a second sub choke member 912, a third sub choke member 914, a fourth sub choke member 916, and A plurality of connections 918 is included.

The connections 918 are connected between the

sub choke members

910, 912, 914 and 914.

According to one embodiment of the present invention, a slot 920 may be formed in some or all of the

sub choke members

910, 912, 914, and 914. For example, as illustrated in FIG. 9, slots 920 may be formed at lower ends of the first sub choke member 910 and the third sub choke member 914, respectively. Here, the slot 920 may widen the width of the beam output from the antenna as described later.

Although not described above, the choke members 904 are arranged spaced a predetermined distance from the reflector plate 900, and some of the distances between the

sub choke members

910, 912, 914 and 916 from the radiation element 902 are Can have different lengths.

Hereinafter, the beam width characteristics when the choke member 904 has no slot and when the slot 920 is formed will be described.

FIG. 10 is a diagram illustrating an electromagnetic field distribution when there is no slot in the choke member and a distribution of electromagnetic fields when a slot is formed in the choke member, and FIG. 11 is a diagram illustrating a change in beam width characteristics in the antenna of FIG. 10.

Referring to FIG. 10, when the slot 920 is formed in the choke member 904, the amount of electromagnetic field reflected between the choke member 904 and the reflector plate 900 (see FIG. 10B) is a slot in the choke member. It is confirmed that there is more than the amount of the electromagnetic field when there is no (see Fig. 10A). As a result, the beam width of the antenna in which the slot 920 is formed in the choke member 904 may be wider than the beam width of the antenna without the slot in the choke member.

Hereinafter, the actual experimental results for the beam width characteristics will be described.

Referring to FIG. 11, the beam width characteristic curve 1100 at an inclination angle of 0 °, the beam width characteristic curve 1102 at −7 °, and −15 ° at an antenna having a slot 920 formed in the choke member 904. The beam width characteristic curve 1104 is shown.

In addition, the beam width characteristic curve 1110 at the inclination angle 0 °, the beam width characteristic curve 1112 at -7 ° and the beam width characteristic curve 1114 at -15 ° are obtained at an inclination angle of the antenna without the slot in the choke member. Shown.

Looking at the beam width

characteristic curves

1110, 1112, and 1114 in the antenna without the slot in the choke member, the beam width is kept wide in the low frequency band but considerably narrowed in the high frequency band.

On the other hand, looking at the beam width

characteristic curves

1100, 1102, and 1104 in the antenna in which the slot 920 is formed in the choke member 904, it is confirmed that the beam width is maintained not only in the low frequency band but also in the high frequency band.

That is, due to the difference in the amount of electromagnetic field reflected between the choke member 904 and the reflector plate 900, it can be seen that the beam width characteristic of the antenna having the slot 920 formed in the choke member 904 is better.

Hereinafter, various characteristics of the antenna having the structure of FIG. 9 will be described.

FIG. 12 is a diagram illustrating return loss characteristics in the antenna of FIG. 9, and FIG. 13 is a diagram illustrating isolation characteristics in the antenna of FIG. 9. FIG. 14 is a diagram illustrating a beam pointing error characteristic of + 45 ° polarization in the antenna of FIG. 9, and FIG. 15 is a diagram of a beam pointing error characteristic of −45 ° polarization in the antenna of FIG. 9.

Referring to FIG. 12, the return loss of the antenna has a value of about −10 μs or less at about 1.64 μs or more, and thus, the return loss characteristic may be maintained well.

Referring to FIG. 13, it can be seen that the isolation between the radiating elements 902 in the antenna has a value of about −30 μs or less at about 1.59 μs or more, and thus the isolation property is excellently maintained.

Referring to FIGS. 14 and 15, a beam pointing error of ± 45 ° polarizations output from the antenna has a value within a range of 2 ° to −2 ° within an inclination angle of 0 ° to −15 °. That is, it can be seen that the beam pointing error of ± 45 ° polarizations is within the allowable range in the inclination angle of 0 ° to -15 °.

Summarizing the first and second embodiments, the antenna of the present invention arranges a choke member surrounding the radiation element in a state spaced apart from the reflecting plate, and sub-choke members included in the choke member. To form a slot in at least one of. As a result, the beam pointing error of the antenna is reduced, the CPR characteristic can be maintained high in the low frequency band and the high frequency band, and the beam width of the antenna can be kept wide.

In addition, since the choke member is coupled to the reflector using a plastic support, the choke member may be easily assembled at the antenna, and the choke member may be changed and installed if necessary.

In addition, as the number of radiating elements increases, the length of the reflecting plate must be increased, which causes the reflecting plate to be distorted and the mechanical stability of the corresponding antenna may not be guaranteed due to vibration, impact, or the like. However, in the antenna of the present invention, since the choke member surrounds the radiation element and the choke member is coupled to the reflector through the plastic support, even if the length of the reflector is increased, the distortion of the reflector can be reduced and vibration, impact, etc. are applied. The mechanical stability of the antenna can be ensured.

The embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having various ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Should be considered to be within the scope of the following claims.

Claims

At least one radiation element arranged on the reflector; And a conductive choke member arranged around the radiation element, wherein the choke member is arranged spaced apart from the reflecting plate by a predetermined distance.
The antenna of claim 1, wherein the choke member is formed to surround the radiation element, and the radiation element has a circular shape.
The choke member of claim 2, wherein the choke member includes a first sub choke member, a second sub choke member, a third sub choke member, and a fourth sub choke member. At least one of a distance between a radiation element, a distance between the second sub choke member and the radiation element, a distance between the third sub choke member and the radiation element and a distance between the fourth sub choke member and the radiation element Is an antenna having a length different from other distances.
The apparatus of claim 3, wherein the reflector comprises: a base member; And vertical members bent vertically from the base member and formed on both side surfaces of the base member, wherein the first sub choke member and the third sub choke member face the corresponding vertical member, the first sub choke The distance between the member and the vertical member and the distance between the third sub choke member and the vertical member are equal, the distance between the second sub choke member and the radiation element and between the fourth sub choke member and the radiation element. The distance is different from the antenna.
5. The antenna of claim 4, wherein the first sub choke member and the third sub choke member are spaced apart from the vertical member.
The method of claim 3, wherein a slot is formed at a lower end of at least one of the sub choke members, and the radiation element includes a plurality of radiation members, wherein at least one of the radiation members is formed with a slot. antenna.
The antenna of claim 3, wherein the choke member further comprises connecting portions connecting between neighboring sub choke members.
A reflecting plate arranged on the reflecting plate; And a conductive choke member surrounding the radiation element and having a first sub choke member, a second sub choke member, a third sub choke member and a fourth sub choke member, wherein the first sub choke member and the radiation element At least one of the distance between the second sub choke member and the radiation element, the distance between the third sub choke member and the radiation element, and the distance between the fourth sub choke member and the radiation element is different An antenna having a length different from the distances.
9. The antenna of claim 8, wherein the choke member is arranged spaced apart from the reflecting plate.
The method of claim 8, wherein the radiation element has a circular shape, at least one of the first sub-choke member to the fourth sub-choke member is formed with a slot, characterized in that the slot is formed in a portion of the radiation element Antenna.
A plurality of radiating elements arranged on the reflecting plate; And a plurality of conductive choke members surrounding the respective radiating elements to satisfy a beam pointing error tolerance at a specific range of inclination angles.
The antenna of claim 11, wherein at least one of the choke members is spaced apart from the reflecting plate, and an inclination angle satisfying the beam pointing error tolerance range is 0 ° to −15 °.
12. The method of claim 11, wherein at least one of the choke members comprises a conductive choke member having a first sub choke member, a second sub choke member, a third sub choke member and a fourth sub choke member, wherein the first sub Distance between the choke member and the radiating element, distance between the second sub choke member and the radiating element, distance between the third sub choke member and the radiating element and between the fourth sub choke member and the radiating element At least one of the distances has a length different from the other distances.