JP2006186841A - Antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna system capable of controlling a main beam and side robes flexibly and securing a service area even in an area relatively near a base station. <P>SOLUTION: The antenna system comprises a first antenna block comprising one first antenna unit or more arranged above a perpendicular direction and a second antenna block comprising one second antenna unit or more arranged under the perpendicular direction of the first antenna block, and an electric tilt angle of the second antenna unit is made larger than that of the first antenna unit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna device used for a base station antenna of a mobile communication system, which is advantageous to be installed in a high undulation place such as a high place such as a mountain top or a low place such as a basin.

Conventional base station antennas for mobile communication systems are arrayed in the vertical direction in order to increase the antenna gain, and show a sharp vertical in-plane directivity in which side lobes are greatly reduced compared to the main beam. FIG. 12 shows a conventional base station antenna for a mobile communication system. Antenna unit 120 _a is configured plurality of N excitation element 121 is disposed vertically. The antenna unit one hundred twenty _a constitute a base station antenna number M number is determined to be located in the vertical direction by a desired antenna gain. Feed network connecting between the feeding point 123 to the antenna units 120 _* feed point 122 _* and antenna systems are generally vertical upper portion of the antenna unit 120 _a and the vertical direction lower portion of the antenna unit supply cable to 120 _m The delay times generated in 124 and 125 are designed to be the same. Therefore, the directivity in the vertical plane shows a sharp characteristic in the directivity direction.

As a method of adjusting the sharp directivity, a method of inserting a tilting phase shifter into a power feeding network as shown in FIG. This is a method in which the tilting phase shifter 126 changes the phase of the power feeding signal fed between the antenna unit 120 _{a at} the top in the vertical direction and the antenna unit 120 _b near the ground surface (not shown). For example, when directing the main beam to the surface direction may be delayed by the phase of the feed signal for feeding to the antenna unit 120 _b than feeder signals fed to the antenna unit 120 _a. For example, when it is desired to set the tilt angle to 10 °, the phase for feeding power to the antenna unit positioned vertically below is delayed by 10 °. For example, when a base station antenna is composed of three antenna units 120 _a , 120 _b , and 120 _c , a power supply signal delayed by 20 ° with respect to 120 _a is supplied to the antenna unit 120 _c .

In addition, as a method for adjusting the directivity of the antenna, a method of mechanically tilting the antenna body as shown in Patent Document 1 is known. FIG. 13 shows a conventional example in which the antenna body is mechanically inclined. An antenna body 131 is fixed to the antenna support 130 by being tilted downward by a bar 135. As a result, the beam is directed downward. In the conventional example shown in FIG. 13, the length of the feeding network 132 from the feeding point 136 to the antenna unit 133 arranged at the upper part in the vertical direction is set longer than the length to the antenna unit 134 when arranged at the lower part in the vertical direction. Therefore, an example is shown in which the phase shift effect works in the sky direction, cancels out the mechanical tilt effect, and the beam is adjusted in the horizontal direction.
JP-T-2001-521711 (FIG. 2)

Conventionally, the antenna directivity adjustment method has been performed in a state where the configuration of the antenna unit is fixed to one type. That is, the configuration of the antenna unit including the excitation element is fixed, and the antenna body using the antenna unit is mechanically tilted, or the phase of the feeding signal of each antenna unit is uniformly changed.
In these methods, fine adjustment to the area where the mobile communication service is provided becomes difficult, and it may be impossible to secure a service area. For example, in a base station antenna installed on a mountain, there is a problem that the reception level decreases in an area that is relatively close to 1 km to 2 km away from the base station.

Mechanical adjustment means as if the adjustment method is direct and fine adjustment is possible, but it is possible to adjust the tilted front beam, but it is orthogonal to the radiation direction of the main beam There is a problem that the beam on the coordinates cannot be adjusted.
This will be briefly described with reference to FIG. Reference numerals 140 to 143 in FIG. 14A denote antenna units. As shown in FIG. 14 (a), the antenna units are arranged on the Z axis at regular intervals. FIG. 14B shows a case where this is mechanically inclined. If the antenna units 140 to 143 are tilted by, for example, 30 ° as the depression angle θ144, the beam in the y-axis direction tilts, but the tilt effect is 0 because Cosφ (90 °) is applied to the beam in the x-axis direction. Become.

FIG. 14C shows the case of electrical tilt. For example, when the electrical tilt angle is set to 30 °, the relative phase difference is set in the order of the antenna units 152, 151, and 150 that are low in the vertical direction with reference to the feed signal that feeds the antenna unit 153 at the top. Power is supplied with a delay of 30 °. Then, the tilt effect can be obtained not only in the y-axis direction but also in the x-axis direction. This is the same as, for example, changing the opening angle of the umbrella. That is, the electrical tilt can affect radio waves in all directions radiated from the antenna, such as the opening angle of the umbrella.
As described above, the electrical tilt is superior to the mechanical tilt. However, since the phase control is uniformly performed, there is a problem that the service area cannot be secured due to the above-described problems.

  The present invention has been made in view of the above points, and provides an antenna device that can flexibly control a main beam and side lobes so that a service area can be secured even in an area relatively close to a base station. Objective.

The present invention includes a first antenna block including one or more first antenna units, and a second antenna block including one or more second antenna units,
The first antenna block and the second antenna block are arranged in the vertical direction, and different electrical tilt angles are given to the first antenna unit and the second antenna unit.

  As described above, according to the present invention, an antenna device that can adjust the directional characteristics flexibly can be realized by configuring the antenna device with two types of blocks having different electrical tilt angles.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]

FIG. 1 shows an embodiment of an antenna device according to the present invention. A first antenna block composed of one or more first antenna units and a second antenna block composed of one or more second antenna units are arranged in the vertical direction, and the first antenna Different electrical tilt angles are given to the unit and the second antenna unit.
The first antenna unit 1 is configured by arranging N excitation elements 2 in the vertical direction. For example, four excitation elements 2 are arranged in the vertical direction, and the electrical tilt angle is given by changing the lengths of the feed lines 4 and 5 from the feed point 3 of the first antenna unit 1. . For example, a tilt angle of 5 ° is given to the first antenna unit 1. M first antenna units 1 are arranged in the vertical direction to form a first antenna block 12.

Similarly to the first antenna unit 1, the second antenna unit 8 disposed below the first antenna block 12 in the vertical direction includes, for example, four excitation elements 2, and each excitation in the second antenna unit. For example, a tilt angle of 15 ° is given by changing the length of a power supply line (not shown) to the element 2. L pieces of the second antenna units 8 are arranged in the vertical direction to form a second antenna block 13.
The first antenna block 12 arranged in the vertical direction and the second antenna block 13 arranged below the first antenna block 12 constitute an antenna device. Here, a feeding cable 6 for supplying a feeding signal from a feeding point 11 of the antenna system to a feeding point 3 of the first antenna unit 1 and a reference arranged at the M-th position in the vertical direction from the first antenna unit 1 The delay time generated between the feeding point of the first antenna unit not denoted by the reference sign and the feeding cable 7 connecting the feeding point 11 of the antenna system is designed to be the same. Notation of each antenna unit and each feeding cable up to the first antenna unit corresponding to the M-th vertical direction is omitted.
Similarly, a power supply cable 9 for supplying a power supply signal from the power supply point 11 of the antenna system to the power supply point 14 of the second antenna unit 8, and a reference sign arranged in the L-th position in the vertical direction from the second antenna unit 8. Is designed so that the delay time generated between the feeding point of the second antenna unit not denoted by and the feeding cable 10 connecting the feeding point 11 of the antenna system is the same. The notation of each antenna unit and each feeding cable up to the second antenna unit corresponding to the L-th vertical direction is also omitted.

Since all the phase delays generated in the feeder cable are designed to be equal, in the embodiment shown in FIG. 1, the tilt angle of the first antenna block 12 is set to the tilt angle of 5 ° of the first antenna unit 1 and the second The tilt angle of the antenna block 13 is set to a tilt angle of 15 ° of the second antenna unit 8.
FIG. 2 shows how to give an electrical tilt angle to each antenna unit. FIG. 2A shows a method of giving a tilt angle by changing the length of the feed line in the antenna unit. In order to give the tilt angle, the lengths of the feed lines from the feed point 3 of the first antenna unit 1 to the respective excitation elements 2a to 2d are made different. What is necessary is just to lengthen the length of the feed line 21 which connects the excitation element 2b and the feed point 3 with respect to the feed line 20 which connects the excitation element 2a and the feed point 3. Similarly, the feed line 22 connecting the excitation element 2 c and the feed point 3 is made longer than the feed line 21. Further, the feed line 23 connecting the excitation element 2 d and the feed point 3 is made longer than the feed line 22. If it is desired to set the tilting angle of the feed line to be 10 °, for example, the relative phase delay (delaying the feed signal to the antenna unit positioned vertically below by 10 °) is generated in the feed line. The length may be set to 10 °.

FIG. 2B shows an example in which a phase shifter for shifting the phase is arranged in the antenna unit. The phase shifter 24 is placed between the feed point 3 and each of the excitation elements 2a, 2b, 2c, 2d, and is connected to the terminal a of the phase shifter 24 connected to the excitation element 2a and to the excitation element 2b. The phase output to each terminal of the terminal b of the phase shifter 24, the terminal c of the phase shifter 24 connected to the excitation element 2c, and the terminal d of the phase shifter 24 connected to the excitation element 2d may be delayed by 10 °. Thus, the electrical tilt angle can be given by the phase shifter.
In FIG. 3A, for example, five first antenna units 1 having a tilt angle of 5 ° constitute the first antenna block 12, and two second antenna units 8 having a tilt angle of 15 ° are second. The directivity in the vertical plane of the antenna device that constitutes the antenna block is shown. The frequency is data at 2.0 GHz. In FIG. 3A, the vertical axis indicates the antenna gain in dBi, the horizontal axis indicates the directivity direction in the vertical plane in deg., The positive direction is the ground direction, and the negative direction is the sky direction. The solid line in FIG. 3A shows the characteristic of this embodiment, and the broken line shows the characteristic of the conventional antenna apparatus in which no electrical tilt angle is given. However, for the purpose of comparison, the conventional antenna device is also composed of seven antenna units in the vertical direction.

  There is a main beam at an angle of 5 °, and both this embodiment and the conventional example show characteristics in which the antenna gain decreases sharply in both the sky direction and the ground direction. In particular, the conventional antenna device has a characteristic that a null is generated in the vicinity of about 17 ° in the ground direction, and the antenna gain is rapidly reduced over an angle of 20 °. On the other hand, in the antenna device of this embodiment, the gain decreases in the angle range of 5 ° to 10 ° as in the conventional antenna device, but the gain of 0 to 5 dBi is maintained in the range of 10 ° to 20 °. The characteristics to be shown. It has been empirically found that the antenna gain in the range of 10 ° to 20 ° greatly affects reception characteristics in an area relatively close to the antenna.

  The data supporting this is shown in FIG. FIG. 4 shows propagation loss characteristics at a frequency of 2.0 GHz when the antenna device of this embodiment is installed at a height of 400 m. (The simulation conditions for the propagation loss characteristics shown below are all at an altitude of 400 m and a frequency of 2.0 GHz.) The horizontal axis indicates the distance in the horizontal direction from the antenna device in Km, and the vertical axis indicates the propagation loss in dB. . The propagation loss in the range of 1 km to 2 km of the conventional antenna device indicated by the broken line is greatly waved around -120 dB, and the minimum level drops to about -146 dB. On the other hand, as shown by the solid line, the characteristics of the antenna apparatus of this embodiment are such that the propagation loss in the range of 1 km to 2 km is centered on -110 dB, and the average 10 dB antenna gain is improved. Moreover, there is no sudden drop seen in the conventional antenna apparatus.

As described above, according to the embodiment of the present invention in which two tilt angles are given, it is possible to greatly improve the propagation loss in the range of 1 km to 2 km where the distance from the antenna device is relatively close.
FIG. 3B shows the vertical in-plane directivity of the example in which the electrical tilt angle of the second antenna unit 8 is 30 °. The electrical tilt angle of the first antenna unit 1 remains 5 °.
In the conventional antenna apparatus, a plurality of nulls can be confirmed in an angle range of 20 ° to 40 °, and the antenna gain undulates about -17 dBi. On the other hand, the characteristics of the antenna device of the embodiment in which the electrical tilt angle of the antenna unit 8 is set to 30 ° are such that there is no null in the angle range of 20 ° to 40 ° and the antenna gain is maintained at -5 dBi or more. Show. In particular, a gain of about 3 dBi is shown near an angle of 30 °. By varying the electrical tilt angle of the combined antenna units in this way, it is possible to adjust the vertical in-plane directivity characteristic of the antenna device to a desired characteristic. With the antenna device according to the present invention, it becomes possible to easily adjust to the required characteristics that differ depending on the area where the antenna device is installed.

FIG. 5 shows another embodiment of the present invention. The same components as those described so far have the same reference numerals and will not be described repeatedly. In the embodiment shown in FIG. 5, the first antenna block 1 includes M first antenna blocks 12 and the second antenna unit 8 includes L second antenna blocks 13. One or more (K) spaces 50 having the same size as the antenna unit 1 and the second antenna unit 8 are provided.
In FIG. 6, four first antenna units 1 with a tilt angle of 5 ° constitute a first antenna block 12, and two second antenna units 8 with a tilt angle of 15 ° constitute a second antenna block. In addition, the directivity in the vertical plane at the frequency of 2.0 GHz of the antenna device in which the space 50 for one antenna unit is provided between the first antenna block 12 and the second antenna block 13 is shown. That is, this is an example in which the first antenna unit 1 of the embodiment shown in FIG. The solid line in FIG. 6 shows the characteristic of the second embodiment, and the broken line shows the characteristic of the conventional antenna apparatus in which no electrical tilt angle is given. The conventional antenna apparatus has a main beam at an angle of about 5 °, and exhibits a characteristic that the antenna gain is suddenly decreased in both the ground direction and the sky direction. On the other hand, the antenna device of this embodiment has the same basic characteristics that the antenna gain is reduced in both the ground direction and the sky direction, but the angle is 10 ° to 20 °. The gain is improved by about 10 dB in the range of °.

Next, in order to confirm the effect of the space 50, the characteristic of the solid line in FIG. 3A is compared with the solid line in FIG.
There is no change in the size of the main beam at an angle of 5 °. The antenna gains in the angle range of 10 ° to 20 ° are particularly different. An antenna gain in an angle range of 12 ° to 17 ° is improved without a drop in gain (about 0 dBi) in the vicinity of an angle of about 12 ° seen in the embodiment having no space 50.
The propagation loss characteristics of this example are shown in FIG. Propagation loss in the range of 1 km to 2 km in the horizontal distance from the antenna device is wavy, but the average is improved by about 2 dB. In the embodiment (solid line) shown in FIG. 4, the range from 1 km to 2 km is about −109 dB, whereas the propagation loss in the same range provided with the space 50 shown in FIG. 7 is about −107 dB.

Thus, it is possible to change the characteristics of the antenna device by providing a space between the first antenna block 12 and the second antenna block 13.
Moreover, although the example where the magnitude | size of the 1st antenna unit 1 and the 2nd antenna unit 8 was equal demonstrated, the case where the magnitude | sizes of the 1st antenna unit 1 and the 2nd antenna unit 8 differ may be sufficient. That is, in order to facilitate the adjustment, the antenna unit can be changed (replaced) in the unit of the size of each antenna unit.

FIG. 8 shows another embodiment of the present invention in which a phase shifter is connected to at least one of the power feed lines that feed power to the first antenna block 12 and the second antenna block 13.
FIG. 8A shows an example in which a phase shifter is connected in the feed line on the first antenna block 12 side. The same components as those described so far have the same reference numerals and will not be described repeatedly. A phase shifter 80 is inserted and connected between the feeding point 11 of the antenna system and the feeding point 3 of the first antenna unit 1. The phase shifter 80 supplies a feeding signal with a variable phase to each feeding point 3 of each first antenna unit 1 constituting the first antenna block 12. The first antenna unit 1 located at the uppermost stage in the vertical direction is supplied with power from a phase shifter 80 by a power supply cable 81. The feeding point of the first antenna unit that does not indicate the Mth reference symbol located at the lowest vertical direction constituting the first antenna block 12 is fed by a feeding cable 82. In FIG. 8A, the description of the antenna unit between the uppermost first antenna unit 1 and the lowermost first antenna unit is omitted. A feeding cable independent from the phase shifter 80 is also connected to the feeding point of each omitted first antenna unit. A phase shifter is not inserted and connected to the second antenna block 13 side.

For example, if the phase of the feed signal fed to the feed point 11 of the antenna system is shifted by -2 ° with the phase shifter 80, the phase supplied to the feed point of each first antenna unit is relatively -2 °. Delayed by phase shifter 80 one by one.
The phase shifter 80 may be configured by any of a mechanical phase shifter or an electrical phase shifter, such as a loaded line type or a hybrid coupled type. In view of the ease of adjustment, a variable phase shifter is more preferable.
FIG. 9A shows the directivity characteristics in the vertical plane when the phase shift amount of the phase shifter 80 is changed in the antenna device of this embodiment. The frequency is 2.0 GHz. The vertical axis represents the antenna gain in dBi, and the horizontal axis represents the angle in the vertical plane in deg. This data is a characteristic of an antenna device in which, for example, five first antenna units 1 with an electrical tilt angle of 5 ° and two second antenna units 8 with an electrical tilt angle of 15 ° are formed.

A characteristic indicated by a solid line in FIG. 9A is a characteristic when the phase shifter 80 does not shift the phase. That is, it is a characteristic of the antenna device itself. The direction of the main beam is an angle of 5 ° equal to the electrical tilt angle given to the first antenna unit 1.
The characteristic indicated by the broken line is obtained by advancing the phase of the first antenna unit positioned vertically by the phase shifter 80 by 4 °. As a result, the direction of the main beam is changed to about 1 °.
The characteristic indicated by the two-dot chain line is that the phase of the first antenna unit positioned in the vertical direction is delayed by 2 ° by the phase shifter 80. As a result, the direction of the main beam changes to about 7 °. It is the part enclosed by the ellipse of the broken line in the figure of Fig.9 (a).

Thus, by changing the phase of the feed signal fed to the first antenna block 12 side by the phase shifter 80, the radiation angle in the vertical plane of the main beam can be changed.
Next, an example in which a phase shifter is connected to the second antenna block 13 side is shown. The same components as those described so far have the same reference numerals and will not be described repeatedly. A phase shifter 83 is inserted and connected between the feeding point 11 of the antenna system and the feeding point 14 of the second antenna unit 8. The phase shifter 83 supplies a feed signal having a variable phase to the feed point 14 of each second antenna unit 8 constituting the second antenna block 13. The second antenna unit 8 positioned in the vertical direction is supplied with power from a phase shifter 83 by a power supply cable 84. The feeding point of the second antenna unit that does not indicate the L-th reference symbol that is located at the lowest vertical direction constituting the second antenna block 13 is fed by a feeding cable 85. In FIG. 8B, the description of the antenna unit between the uppermost second antenna unit 8 and the lowermost second antenna unit constituting the second antenna block 13 is omitted. . A feeding cable independent from the phase shifter 83 is also connected to the feeding point of each omitted first antenna unit. A phase shifter is not inserted and connected to the first antenna block 12 side.

FIG. 9B shows the vertical in-plane directivity characteristics when the phase shift amount of the phase shifter 83 is changed in the antenna device of this embodiment. The vertical axis represents the antenna gain in dBi, and the horizontal axis represents the angle in the vertical plane in deg. This data is a characteristic of an antenna device in which, for example, five first antenna units 1 with an electrical tilt angle of 5 ° and two second antenna units 8 with an electrical tilt angle of 15 ° are formed.
A characteristic indicated by a broken line in FIG. 9B is a characteristic when the phase shifter 83 does not shift the phase. That is, it is a characteristic of the antenna device itself. With respect to this characteristic, the solid line represents the characteristic obtained by delaying the phase of the second antenna unit positioned vertically downward by 5 ° with the phase shifter 83. Further, the characteristics delayed by 15 ° are indicated by a two-dot chain line.

  As the tilt angle is increased by the broken line, the solid line, the two-dot chain line, and the phase shifter 83, the side lobe shown in FIG. 9B is also moved to the ground side. With respect to the characteristics of the two-dot chain line having a tilt angle of 30 ° by the phase shifter 83, the antenna gain near the angle of 30 ° is improved by about 5 dBi with respect to the solid line. In this way, by increasing the tilt angle of the second antenna block 13, the antenna gain in the portion with the large depression angle can be improved. These characteristics are shown in FIG. 9B surrounded by a dashed ellipse. The point to be noted here is that the directivity of the main beam does not change even when the phase of the feed signal fed to the second antenna block 13 by the phase shifter 83 is changed.

In this way, it is possible to adjust only the side lobe by controlling the phase of the power feeding signal fed to the second antenna block 13 by the phase shifter 83.
FIG. 8C shows an embodiment in which a phase shifter is connected to each of the feed lines of the first antenna block 12 and the second antenna block 13. The example shown in FIG. 8C is the same as the example of FIG. 8A in which a phase shifter is inserted and connected to the feed line of the first antenna block 12 described above, and the phase shift to the feed line of the second antenna block 13. This is a combination of the example of FIG. The phase shifter 80 controls the phase of the feed signal that feeds power to the first antenna block 12 to vary the directivity of the main beam, and the phase of the feed signal that feeds power to the second antenna block 13 is shifted by the phase shifter 83. The directivity of the side beam can be varied by controlling with. Since each configuration has already been described, description thereof is omitted here.

FIG. 10 shows an embodiment in which power control can be performed in addition to phase shift control. FIG. 10 shows a power distributor added to the embodiment shown in FIG. 8C in which the first antenna block 12 and the second antenna block 13 described above can be controlled in phase shift independently. Is. The same components as those described so far have the same reference numerals and will not be described repeatedly.
FIG. 10 illustrates a phase shifter 80 that controls the phase of a power feeding signal that feeds power to the first antenna block 12, a phase shifter 83 that controls the phase of a power feeding signal that feeds power to the second antenna block 13, and an antenna. This is an example in which a power distributor 100 is connected to the power feeding point 11 of the system.

  The power distributor 100 distributes the feeding power input to the feeding point 11 of the antenna system to the phase shifter 80 and the phase shifter 83. For example, the power supplied to the second antenna block 13 that radiates the third lobe in an area relatively close to the place where the antenna device is disposed is smaller than the power supplied to the first antenna block 12 that radiates the main beam. It is often better to do. With this configuration, it is possible to more efficiently use the supplied power, and to control the directivity of the antenna device more flexibly.

FIG. 11 shows another embodiment of the antenna device of the present invention. FIG. 11 shows an example in which the antenna device according to the present invention is configured by using, for example, a three-frequency excitation element as the excitation element. The excitation element 110 _a is an antenna corresponding to three frequencies, and 110 _a , 110 _b , 110 _c , and 110 _d are arranged in the vertical direction to constitute an antenna unit 115. A feeding signal in which three frequencies are combined by the duplexer 111 is supplied to the feeding point 116 of the antenna unit 115 through one feeding line. For example, a power supply signal of 800 MHz is supplied to the duplexer 111 by the power supply cable 112, for example, a power supply signal of 1.5 GHz is supplied by the power supply cable 113, and a power supply signal of 2.0 GHz, for example, is supplied by the power supply cable 114.

Power feed signals of three frequencies are supplied to the power feed line from the duplexer 111 to the feed point 116 and the excitation elements 110 _a , 110 _b , 110 _c , and 110 _d . For example, it is assumed that the antenna unit 115 constitutes a first antenna block as the first antenna unit. For example, it is assumed that the electrical tilt angle is set to 5 °. This electrical tilt angle is set by adjusting the length of the feed line to each excitation element in the antenna unit 115. Since the length of the feed line is determined based on a certain frequency, when the three frequencies are shared, the phase is shifted and the electrical tilt angle is changed at a frequency other than the frequency used as the reference. Even if the frequency changes, the length of the feed cables 112, 113, 114 between the duplexer 111 and the supply source that generates the feed signal of each frequency is set so that the electrical tilt angle becomes 5 °, for example. Adjusted. That is, since the duplexer is provided in a one-to-one relationship for each antenna unit, the tilt angle can be adjusted by changing the length of the feed cable on the feed signal source side of the duplexer.

It is easy to increase the electrical tilt angle of the antenna unit 115 to form the second antenna block, and the antenna device of the present invention can be configured by the excitation element shared by the three frequencies.
The antenna device can be downsized by sharing the excitation element with three frequencies. In particular, since the antenna device can be stored in one radome, there are many advantages such as the strength of the antenna installation location.
As described above, according to the antenna device of the present invention, it is possible to flexibly adjust the directivity characteristics of the antenna. In the description so far, the example has been described in which the tilt angle of the second antenna block 13 disposed below in the vertical direction is larger than the tilt angle of the first antenna block 12 disposed above in the vertical direction. . However, the present invention is not limited to this combination. For example, when the antenna device of the present invention is installed in a low land such as a basin, the second antenna block is arranged in the vertical direction contrary to the example described above, although it depends on the characteristics of the region. It is also assumed that it is better to set the electrical tilt angle 13 smaller than the tilt angle of the first antenna block 12 arranged in the vertical direction.

  Further, the description of the present invention has not limited the numerical values of the constituent elements. This is because the optimum combination changes depending on the place where the antenna device is installed. According to the present invention, it is possible to optimally adjust the antenna directivity in any situation.

It is a figure which shows one Example of the antenna device by this invention. It is a figure which shows how to give the electrical tilt angle to an antenna unit. It is a figure which shows the directivity in a vertical plane of the antenna apparatus of this invention. It is a figure which shows the propagation loss characteristic of the antenna apparatus of this invention. It is a figure which shows the other Example of this invention. FIG. 6 is a diagram illustrating an example of directivity in a vertical plane of the antenna illustrated in FIG. 5. It is a figure which shows the example of the propagation loss characteristic of the antenna shown in FIG. It is a figure which shows the other Example of this invention which connected the phase shifter. It is a figure which shows the vertical in-plane directivity characteristic of the antenna of this invention which connected the phase shifter. It is a figure which shows the other Example of this invention. It is a figure which shows the other Example of this invention. It is a figure which shows the base station antenna for the conventional mobile communication systems. It is a figure which shows the prior art example which inclined the antenna main body mechanically. It is a figure explaining the difference between mechanical tilt and electrical tilt.

Claims (6)

A first antenna block composed of one or more first antenna units, and a second antenna block composed of one or more second antenna units;
The first antenna block and the second antenna block are arranged in a vertical direction,
An antenna device, wherein the first antenna unit and the second antenna unit have different electrical tilt angles.   The second antenna block is disposed vertically below the first antenna block, and the electrical tilt angle of the second antenna unit is larger than that of the first antenna unit constituting the first antenna block. The antenna device according to claim 1.   The space between the first antenna block and the second antenna block is provided with a space that is at least one size larger than at least one of the first and second antenna units. The antenna device according to claim 1 or 2.   4. The antenna according to claim 1, wherein a phase shifter is connected to at least one of a feeding line that feeds power to the first antenna block and the second antenna block. 5. apparatus.   5. The power distributor for distributing the power supplied to the antenna block is connected to a power supply line that supplies power to the first antenna block and the second antenna block. The antenna device according to any one of the above.   6. The antenna device according to claim 1, wherein the antenna element is an excitation element corresponding to a plurality of frequencies, and a duplexer is connected to an input of the antenna unit.

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