JP2016165086A - Array antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an array antenna capable of simplifying a configuration of a feeder circuit while including a plurality of paths.SOLUTION: An array antenna 1 comprises groups A, B, C, and D each including a plurality of radiation elements 10 which are arranged in such a matrix shape that even numbers of radiation elements are included in a horizontal direction and a vertical direction. Signals of a system that is different from each other are supplied to each of the groups A, B, C, and D. The plurality of radiation elements 10 in each of the groups A, B, C, and D are set in such a manner that power supply phases for power supply of signals are equal or the power supply phases are made reverse in one of or both the horizontal direction and the vertical direction for a pair of neighboring radiation elements 10 without being overlapped among the groups A, B, C, and D.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an array antenna.

  In the MIMO (Multiple Input Multiple Output) communication technology, communication is performed using a plurality of paths between transmission and reception formed by using a plurality of antennas.

  In Patent Document 1, there are provided a plurality of antennas, amplitude adjusting means provided for the plurality of antennas, respectively, for adjusting the amplitude of the signal, and connected to the plurality of antennas for adjusting the phase of the signal. Control means for controlling the correlation coefficient of the transmission signal by controlling the phase adjustment means, the amplitude adjustment means and the phase shift adjustment means, adjusting the amplitude and phase of the transmission signals transmitted from the plurality of antennas Are described.

JP 2013-93658 A

By the way, when a plurality of antennas are used, it is necessary to secure a place for installing the antennas. For this reason, there is a need for a multi-beam antenna that can radiate radio waves (beams) in a plurality of directions. The multi-beam antenna is an array antenna including a plurality of radiating elements. In the multi-beam antenna, a plurality of radiating elements are divided into a plurality of groups, a signal of a different system is fed for each group, and a phase shift difference is provided for the signal for each system. For this reason, the complicated electric power feeding circuit which sets a phase shift difference was required.
An object of the present invention is to provide an array antenna that has a plurality of paths and can have a simple configuration of a power feeding circuit.

For this purpose, the array antenna to which the present invention is applied has a plurality of radiations arranged in a matrix so as to be an even number in each of the first direction and the second direction intersecting the first direction. A plurality of groups each having an element are provided, and each group constituting the plurality of groups is fed with signals of different systems, and the plurality of radiating elements of each group are adjacent to each other without overlapping between the groups. In the radiating element pair, the feeding direction in which the signal is fed is the same, or the feeding direction is set to be opposite to each other in one or both of the first direction and the second direction. .
In such an array antenna, in a plurality of radiating elements of each group, a radiating element pair in which the feeding directions are set to be opposite to each other is such that one radiating element is inverted with respect to the other radiating element. Can be a feature.

The plurality of radiating elements in each group may be alternately arranged between two or more groups.
Thereby, an array antenna can be made small compared with the case where it does not arrange alternately.

A plurality of radiating elements in at least one group of each group are polarization shared, and signals of different systems are fed by the polarization.
Thereby, it can be set as an array antenna for polarization sharing.

  Further, in such an array antenna, a plurality of radiating elements of each group are provided on a side opposite to a side of radiating radio waves of a plurality of radiating elements of each group, and a power feeding circuit that feeds the plurality of radiating elements of each group And a housing that houses the power feeding circuit, and a cover that is provided on the side that radiates radio waves of each of the plurality of radiating elements of each group and is combined with the housing to protect the plurality of radiating elements and the power feeding circuit of each group. Furthermore, it can be characterized by comprising.

  According to the present invention, it is possible to provide an array antenna that can have a simple configuration of a power feeding circuit while having a plurality of paths.

It is a figure explaining an example of the array antenna in 1st Embodiment. FIG. 6 is a diagram in which a plurality of radiating elements of an array antenna are arranged in four groups. It is a figure explaining the relationship between the electric power feeding phase of two adjacent radiation elements, and the radiation | emission direction of an electromagnetic wave (beam). (A) is a case where the feeding phase is in-phase (0 °), and (b) is a case where the feeding phase is opposite (0 ° and 180 °). It is a figure which shows the radiation | emission direction of the main lobe in the array antenna shown in FIG. It is a figure explaining the electric power feeding circuit in the case of supplying electric power by providing a phase difference in a pair of radiation element. (A) is a conceptual diagram in the case of providing a phase difference using a hybrid circuit, (b) is a diagram in the case of providing a phase difference using a delay line (delay line), and (c) is a feeding direction of a pair of radiating elements. It is a figure at the time of reverse. It is a top view of the dipole antenna as an example of a radiation element. (A) is a plan view of one surface, (b) is a plan view of the other surface. FIG. 10 is a diagram in a case where a phase difference is provided using a hybrid circuit when signals having different phases are fed between pairs in eight pairs of radiating elements. FIG. 11 is a diagram in a case where a phase difference is provided using a delay line (delay line) when signals having different phases are fed between eight pairs of radiating elements. It is a figure explaining the electric power feeding circuit at the time of reversing the electric power feeding direction of an radiating element between eight pairs in 8 pairs of radiating elements. It is an example of the array antenna in 2nd Embodiment. It is a figure which shows the gain [dB] of the electromagnetic wave of the horizontal direction (within a horizontal surface) in the vertical direction 0 degree. (A) is a figure explaining the direction of an electromagnetic wave, (b) is vertical polarization, (c) is horizontal polarization. It is a figure which shows the gain [dB] of the electromagnetic wave in the surface inclined in 19 degrees of perpendicular directions. (A) is a figure explaining the direction of an electromagnetic wave, (b) is vertical polarization, (c) is horizontal polarization. It is a figure which shows the gain [dB] of the electromagnetic wave of the vertical direction (in a vertical surface) in a horizontal direction 0 degree. (A) is a figure explaining the direction of an electromagnetic wave, (b) is vertical polarization, (c) is horizontal polarization. It is a figure which shows the gain [dB] of the electromagnetic wave in the surface inclined in 19 degrees of horizontal directions. (A) is a figure explaining the direction of an electromagnetic wave, (b) is vertical polarization, (c) is horizontal polarization.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[First Embodiment]
FIG. 1 is a diagram for explaining an example of an array antenna 1 according to the first embodiment.
The array antenna 1 includes a plurality of radiating elements 10, a power feeding circuit 20, a housing 30, and a cover 40.
Here, each of the plurality of radiating elements 10 is a dipole antenna as an example. As an example, a total of 64 radiating elements 10 are arranged, 8 in the horizontal direction and 8 in the vertical direction. The direction along the array antenna 1 is defined as a horizontal direction as an example of the first direction and a vertical direction as an example of the second direction, and the direction perpendicular to the array antenna 1 is defined as a radiation direction.
These radiating elements 10 are divided into four groups as will be described later. The radiating elements 10 of each group are alternately arranged in the horizontal direction and the vertical direction. Therefore, the radiating elements 10 for each group are arranged at intervals P in the horizontal direction and the vertical direction.
In this case, the first direction in the horizontal direction and the second direction in the vertical direction are orthogonal to each other, but the first direction and the second direction may not be orthogonal but may intersect. In the following description, the first direction is the horizontal direction and the second direction is the vertical direction.

Each radiating element 10 has two radiating conductors (refer to conductors 12A and 12B in FIG. 6 described later) arranged in the horizontal direction. Therefore, these radiating elements 10 transmit and receive horizontally polarized waves. That is, the array antenna 1 is a single polarization array antenna that transmits and receives horizontal polarization.
Note that the two radiating conductors of each radiating element 10 may be arranged in the vertical direction. In this case, these radiating elements 10 transmit and receive vertically polarized waves. That is, the array antenna 1 is a single-polarized array antenna that transmits and receives vertically polarized waves.

The power feeding circuit 20 is formed using, for example, a PCB (Printed Circuit Board) in which a conductor film (metal foil) is provided on both surfaces of a dielectric substrate. At this time, the conductor film on one surface is left as a reference conductor to which a reference potential (ground potential) is supplied, and a signal conductor is formed on the conductor film on the other surface. A reference conductor and a signal conductor provided with a dielectric substrate in between constitute a microstrip line.
At this time, the reference conductor also functions as a reflector.
The array antenna 1 may include a reflector formed of a metal material on the back surface (the side opposite to the radiation direction) of the feeder circuit 20.

The housing 30 is provided on the side opposite to the radiation direction and accommodates the plurality of radiation elements 10 and the power feeding circuit 20. The housing 30 is formed of, for example, a metal material such as iron, SUS, aluminum, or copper, a resin material, or FRP (Fiber Reinforced Plastics).
The cover 40 is provided on the radial direction side and is combined with the casing 30 to protect the plurality of radiating elements 10 and the power feeding circuit 20. The cover 40 is made of, for example, a low dielectric constant and low dielectric loss material that easily transmits radio waves, such as a resin material or FRP.

FIG. 2 is a diagram in which a plurality of radiating elements 10 of the array antenna 1 are arranged in four groups. Here, the four groups are denoted as A group, B group, C group, and D group. The four groups may be denoted as A, B, C, and D. A different signal is transmitted for each group. That is, four different signals are transmitted to the array antenna 1 and radio waves of four different signals are radiated.
In FIG. 2, the feeding phase of each radiating element 10 is indicated by “+” and “−”. “+” Indicates that the feeding phase is 0 °, and “−” indicates that the feeding phase is 180 °. That is, signals having different feeding phases are fed even by the radiating elements 10 belonging to the same group. The case of the same feeding phase is denoted as in-phase, and the case of feeding phases different by 180 ° is denoted as reverse phase.

In FIG. 2, the arrangement of the plurality of radiating elements 10 of the array antenna 1 is distinguished by row (R) and column (C). That is, the arrangement of the radiating elements 10 in the horizontal direction is set as a row (R), and in the vertical direction, it is expressed as a row R1, a row R2,. Further, the arrangement of the radiating elements 10 in the vertical direction is a column (C), and in the horizontal direction, the column C1, column C2,.
The radiating element 10 arranged in the column C1 (the position of R1C1) in the row R1 is denoted as the radiating element 10 of R1C1.

As shown in FIG. 2 surrounded by a broken line, four (row R1 to row R4) in the row (R) direction and four (column C1 to column C4) in the column (C) direction are basic units. That is, the 16 radiating elements 10 are basic units and are repeated in the horizontal direction, the vertical direction, and the oblique 45 ° direction.
Hereinafter, groups A, B, C, and D in this basic unit will be described.

  Four radiating elements 10 of group A are arranged in R1C1, R1C3, R3C1, and R3C3. That is, every other horizontal and vertical directions are arranged. That is, the radiating elements 10 of the group A are paired in the horizontal direction and the vertical direction. The feeding phases of the radiating elements 10 of group A are all 0 ° (in-phase).

  Four radiating elements 10 of group B are arranged in R2C1, R2C3, R4C1, and R4C3. That is, every other horizontal and vertical directions are arranged. That is, the radiating elements 10 of group B are paired in the horizontal direction and the vertical direction, respectively. The feeding phases of the radiating elements 10 of group B are 0 ° for R2C1 and R2C3 and 180 ° for R4C1 and R4C3. That is, the feeding phase is reversed between the radiating elements 10 that are adjacent pairs in the vertical direction (radiating element pairs).

  Four radiating elements 10 of group C are arranged in R1C2, R1C4, R3C2, and R3C4. That is, every other horizontal and vertical directions are arranged. That is, the radiating elements 10 of group B are paired in the horizontal direction and the vertical direction, respectively. The feeding phases of the radiating elements 10 of group C are 0 ° for R1C2 and R3C2, and 180 ° for R1C4 and R3C4. That is, the feeding phase is reversed between the pair of radiating elements 10 adjacent in the horizontal direction (adjacent radiating element pairs).

  Four radiating elements 10 of group D are arranged in R2C2, R2C4, R4C2, and R4C4. That is, every other horizontal and vertical directions are arranged. That is, the radiating elements 10 of group B are paired in the horizontal direction and the vertical direction, respectively. The feeding phases of the radiating elements 10 of group D are 0 ° for R2C2 and R4C4 and 180 ° for R2C4 and R4C2. That is, the feeding phase is reversed between the pair of radiating elements 10 adjacent to each other in the horizontal direction and the vertical direction (adjacent radiating element pairs).

  As described above, in the array antenna 1, the groups A, B, C, and D do not overlap with each other, and the adjacent radiating element pairs have the same feeding direction, either the horizontal direction or the vertical direction, or In both cases, the feeding directions are set to be opposite to each other. And the radiation element 10 which comprises the groups A, B, C, and D is alternately inserted and arrange | positioned. Thereby, the size of the array antenna 1 is reduced.

FIG. 3 is a diagram for explaining the relationship between the feeding phase of two adjacent radiating elements 10 and the radiation direction of a radio wave (beam). FIG. 3A shows the case where the feeding phase is in-phase (0 °), and FIG. 3B shows the case where the feeding phase is opposite (0 ° and 180 °).
As shown in FIG. 3A, when the feeding phase is the same phase (0 °), the main lobe 2 of the radio wave (beam) is radiated along the radiation direction.
On the other hand, when the feeding phase is opposite (0 ° and 180 °), as shown in FIG. 3B, the main lobes 2A and 2B are divided into two in the direction in which the two radiating elements 10 are arranged, Each is emitted obliquely with respect to the radial direction. When the main lobes 2A and 2B are not distinguished from each other, they are represented as main lobes 2.

  Therefore, in the array antenna 1, a group of radiating elements 10 (group A in FIG. 2) whose feeding phase is the same phase (0 °) and a radiating element 10 whose feeding phases are opposite (0 ° and 180 °). When groups (groups B, C, and D in FIG. 2) are mixed and a signal is fed by a different system for each group, radio waves (beams) of different signals can be emitted in different directions. That is, it becomes a multi-beam antenna.

  FIG. 4 is a diagram showing the direction of the main lobe 2 in the array antenna 1 shown in FIG. FIG. 4 is a view of the array antenna 1 as seen from the radiation direction. The radiating directions of the main lobes 2 radiated from the radiating elements 10 of the groups A, B, C, and D are shown with the symbols A, B, C, and D, respectively. Since the array antenna 1 is viewed from the radiation direction, the main lobes 2 of the groups B, C, and D are radiated in the direction of ± 45 ° with respect to the horizontal direction, the vertical direction, and the horizontal and vertical directions. Although it looks like it is radiated obliquely with respect to the radiation direction.

Since the radiating elements 10 of the group A have the same feeding phase, the main lobe 2 is radiated along the radiation direction.
Since the radiating elements 10 of the group B have the feeding phase in the vertical direction and the opposite phase, the main lobe 2 is divided into two in the vertical direction and radiated obliquely with respect to the radiating direction.
Since the radiating element 10 of group C has a feeding phase that is opposite in the horizontal direction, the main lobe 2 is divided into two in the horizontal direction and radiated obliquely with respect to the radiating direction.
In the radiating element 10 of group D, the feeding phases are opposite to each other in the horizontal direction and the vertical direction, so the main lobe 2 is divided into four in the ± 45 ° direction with respect to the horizontal direction and the vertical direction. In contrast, it is emitted diagonally.

In the array antenna 1, when power is supplied to the plurality of radiating elements 10 in the same phase, the radiating elements 10 may be arranged in an array in the same direction, and a signal may be distributed to the radiating elements 10 by the power feeding circuit 20 to be fed. That is, the power feeding circuit 20 may function as a distributor.
Next, the power feeding circuit 20 in the case where power is fed to the pair of radiating elements 10 in the opposite phase will be described.

FIG. 5 is a diagram for explaining a power feeding circuit 20 in the case where power is fed with a phase difference provided between the pair of radiating elements 10A and 10B. FIG. 5A is a conceptual diagram in the case of providing a phase difference using a hybrid circuit, FIG. 5B is a diagram in the case of providing a phase difference using a delay line (delay line) 22, and FIG. It is a figure at the time of feeding direction of a pair of radiation elements 10A and 10B being reversed. Here, the feeding direction of the radiating elements 10A and 10B is indicated by arrows.
The two radiating elements 10A and 10B have the same feeding direction when the same signal is fed. When the same signal is fed, the same phase is fed. When the same signal is fed, the feeding direction is different. Is supplied.

As shown in FIG. 5A, when power is supplied with a phase difference between the pair of radiating elements 10A and 10B, for example, a hybrid circuit (indicated as HYB in FIG. 5A) 21 is used. The hybrid circuit 21 is a circuit that provides a phase difference in a high-frequency circuit. Here, the pair of radiating elements 10A and 10B are arranged in the same feeding direction.
As a hybrid circuit for generating a phase difference of 180 °, a rat race circuit or the like is known.

FIG. 5B shows a case where the delay line 22 is used as one method for generating a phase difference of 180 °. Again, the pair of radiating elements 10A and 10B are arranged in the same feeding direction.
When the phase difference is 180 °, it is necessary to delay the phase shift of the signal supplied to the radiating element 10B arranged on the right side by 180 ° with respect to the radiating element 10A arranged on the left side. Therefore, the delay line 22 is provided in the path for supplying power to the right radiating element 10B to delay the phase. The length of the delay line 22 is set so that the phase difference between the signal input to the radiating element 10A and the signal input to the radiating element 10B is 180 °. That is, the length of the delay line 22 is set so that the signal propagation time is λ / 2 when the signal on the power feeding circuit 20 is λ.

  However, when a phase difference of 180 ° is provided in the pair of radiating elements 10A and 10B, the feeding direction may be reversed as shown in FIG. By doing so, the phase difference of 180 ° can be achieved between the radiating element 10A and the radiating element 10B without using the hybrid circuit 21 and the delay line 22. That is, the power supply circuit 20 can be configured simply as in the case where power is supplied to the plurality of radiating elements 10 in phase.

Next, as an example of the radiating element 10, it will be described that the feeding direction is reversed with a dipole antenna.
FIG. 6 is a plan view of a dipole antenna as an example of the radiating element 10. 6A is a plan view of one surface, and FIG. 6B is a plan view of the other surface.
A dipole antenna, which is an example of the radiating element 10, is formed using, for example, a PCB in which a conductor film (metal foil) is provided on both surfaces of the dielectric substrate 11.
The conductor film on one surface includes two radiating conductors 12A and 12B, two conductors 12C and 12D extending from portions where the two radiating conductors 12A and 12B face each other, and 2 The conductor 12E connecting the conductors 12C and 12D is processed. The two conductors 12C and 12D are connected by a conductor 12E on the side opposite to the radiation conductors 12A and 12B. When the conductors 12A, 12B, 12C, 12D, and 12E are not distinguished, they are expressed as the conductor 12.

The conductor film on the other surface is processed into a conductor 13 bent into a U shape. The conductor 13 is disposed so that the U-shaped portion overlaps the two conductors 12C and 12D on one surface.
The radiating element 10 radiates radio waves (beams) by being fed by a microstrip line composed of the conductors 12 and 13.

Now, as shown in FIG.6 (b), the conductor 13 is U-shaped and asymmetrical. Therefore, the dipole antenna, which is an example of the radiating element 10, has a phase difference of 180 ° between the case where power is supplied in the direction of FIG. 6A and the case where power is supplied in the direction of FIG. become. Thus, in the radiating element 10 having asymmetry, the phase of the radiated radio wave can be changed by 180 ° by inverting (turning it over) and disposing it. Here, inverting the orientation (turning it over) is referred to as inverting the feeding direction of the radiating element 10. When the feeding direction of one radiating element 10A in the pair of radiating elements 10A and 10B is reversed with respect to the other radiating element 10B, the feeding direction of the pair of radiating elements 10A and 10B is expressed as being opposite. .
When the direction of the radiating element 10 is reversed, the positions of the conductor 12 and the conductor 13 with respect to the dielectric substrate 11 may be reversed. In this way, the power feeding circuit 20 can be further simplified.

Next, the power feeding circuit 20 that feeds signals to the plurality of radiating elements 10 of the array antenna 1 will be described.
FIG. 7 is a diagram for explaining a case where a phase difference is provided using the hybrid circuit 21 when signals having different phases are fed between the pairs of the radiating elements 10. This shows an example of the radiating element 10 included in the group C of FIG. The feeding phase is 0 ° for the radiating elements 10 included in the columns C2 and C6, and 180 ° for the radiating elements 10 included in the columns C4 and C8.
Here, if the feeding directions (directions of arrows) of the radiating elements 10 are arranged in the same manner, the hybrid circuit 21 for setting the phase difference is required as described with reference to FIG.
Then, as shown in FIG. 7, a hybrid circuit 21 must be provided between the signal input and the radiating element 10. For this reason, the electric power feeding circuit 20 will become large. Moreover, since the interval P (see FIG. 1) between the radiating elements 10 is set according to the characteristics of the radio wave, it is difficult to arbitrarily increase the interval P between the radiating elements 10. For this reason, the power supply circuit 20 becomes complicated, for example, constituted by a plurality of PCBs.
Moreover, since the hybrid circuit 21 is also required for the radiating elements 10 of the other groups (groups A, B, and D), the power feeding circuit 20 is further complicated.

FIG. 8 is a diagram illustrating a case where a phase difference is provided by using a delay line 22 in the case of supplying signals of different phases between pairs in the eight pairs of radiating elements 10.
If the feeding direction (direction of the arrow) of the radiating element 10 is the same, the delay line 22 for delaying the phase is provided as described with reference to FIG.
Then, as shown in FIG. 8, a delay line 22 must be provided between the signal input and the radiating element 10. The width of the conductor on the PCB is set by the required impedance. Further, when the interval between the conductors is narrowed, the coupling between the conductors becomes stronger. Therefore, since it is difficult to set the width and interval of the conductor on the PCB in order to provide the delay line 22, a space for arranging the conductor is required. Moreover, since the interval P (see FIG. 1) between the radiating elements 10 is set according to the characteristics of the radio wave, it is difficult to arbitrarily increase the interval P between the radiating elements 10. For this reason, the power supply circuit 20 becomes complicated, for example, constituted by a plurality of PCBs.
In addition, since the conductor and the delay line 22 for supplying power to the radiating elements 10 of other groups (groups A, B, and D) are required, the power supply circuit 20 is further complicated.

FIG. 9 is a diagram for explaining the power feeding circuit 20 when the power feeding direction of the radiating elements 10 is reversed between the pairs in the eight pairs of radiating elements 10.
Since the feeding direction of the radiating element 10 is reversed between the pairs, it is not necessary to use the hybrid circuit 21 or the delay line 22. Therefore, it is suppressed that the electric power feeding circuit 20 becomes complicated.
FIG. 9 shows the group C in FIG. Then, as shown in FIG. 9, power feed lines are concentrated on the left side and connected to the signal input. Conversely, for group A, the feed lines can be concentrated to the right and connected to the signal input. At this time, the feed lines connected to the radiating elements 10 do not cross each other. That is, the feed line connected to the radiating element 10 of the group A and the feed line connected to the radiating element 10 of the group C can be configured by one PCB.
Similarly, the feed line connected to the radiating element 10 of the group B and the feed line connected to the radiating element 10 of the group D can be configured as another single PCB.
Therefore, the power feeding circuit 20 can be composed of at most two PCBs.

[Second Embodiment]
The array antenna 1 in the first embodiment has a single polarization. In the array antenna 1 according to the second embodiment, each radiating element 10 is shared with polarization.
FIG. 10 is an example of the array antenna 1 in the second embodiment.
Since each radiating element 10 is the same as that of the first embodiment except that each radiating element 10 is shared with polarization, the same reference numerals are given and description thereof is omitted.
When the radiating element 10 is a dipole antenna as an example, two dipole antennas described in FIG. 6 in the first embodiment may be combined to form a cross dipole.
In this way, four systems of signals are handled in the first embodiment, but eight systems of signals can be handled in the second embodiment.
Also in this case, the power feeding circuit 20 can be configured by at most two PCBs.
Note that the radiating elements 10 in one or more of the groups A, B, C, and D may be shared with the polarization without making all the radiating elements 10 of the array antenna 1 share the polarization.

Below, the Example about the gain with respect to the radiation direction of the array antenna 1 is described. Here, the frequency was 5.25 GHz, and the spacing P between the radiating elements 10 was 1.53λ with respect to the wavelength λ in free space.
When the interval P between the radiating elements 10 is 1λ or more, a grating lobe appears in addition to the main lobe 2. In this case, in addition to the main lobe 2, a grating lobe can be used as a path. In the case where the grating lobe is not used, the interval P between the radiating elements 10 may be less than 1λ.
In the following, the direction perpendicular to the array antenna 1 (radiation direction) is represented as 0 °, and the horizontal and vertical inclination angles are represented as an angle [°]. In addition, it describes with 30 degrees of horizontal directions.

FIG. 11 is a diagram illustrating the gain [dB] in the horizontal direction (in the horizontal plane) at the vertical direction of 0 °. FIG. 11A is a diagram for explaining the direction of radio waves, FIG. 11B shows gain for each angle in vertical polarization, and FIG. 11C shows gain for each angle in horizontal polarization.
As shown in FIG. 11A, the gain in the horizontal direction (in the horizontal plane) was obtained by simulation at 0 ° in the vertical direction of the array antenna 1.
As described with reference to FIG. 4, in the direction (radiation direction) perpendicular to the array antenna 1 (vertical direction 0 °, horizontal direction 0 °), radio waves from the radiating element 10 of group A are strongly emitted. As shown in FIGS. 11B and 11C, the radio wave from the radiating element 10 of group A is strongly emitted in the direction (radiation direction) perpendicular to the array antenna 1 in both vertical polarization and horizontal polarization. Yes. A grating lobe appears in the horizontal direction of 40 °.

As described with reference to FIG. 4, the radio wave from the radiation element 10 of the group C is strongly emitted in the direction inclined in the horizontal direction from the direction perpendicular to the array antenna 1 (radiation direction). As shown in FIGS. 11B and 11C, the radiating element 10 of the group C is located at 20 ° in the horizontal direction with respect to the direction (radiation direction) perpendicular to the array antenna 1 for both vertical polarization and horizontal polarization. There is a strong radio wave from.
The radio wave from the radiation element 10 of the group C appears in a range of angles (null) where the radio wave from the radiation element 10 of the group A is weak. Further, the radio waves from the groups B and D are not shown in the figure because they are in the null position in the vertical direction as shown in FIG.
That is, the radio wave from the radiating element 10 of group A and the radio wave from the radiating element 10 of groups B, C, and D have a low correlation.

FIG. 12 is a diagram showing the gain [dB] in a plane inclined in the vertical direction of 19 °. 12A illustrates the direction of radio waves, FIG. 12B illustrates the gain for each angle in the vertical polarization, and FIG. 12C illustrates the gain for each angle in the horizontal polarization.
As shown in FIG. 12A, the gain in the horizontal direction within a plane inclined at 19 ° in the vertical direction from the direction perpendicular to the array antenna 1 was obtained by simulation.
As described with reference to FIG. 4, radio waves from the radiating element 10 of group B are strongly emitted in a direction inclined from the direction perpendicular to the array antenna 1 (radiation direction). As shown in FIGS. 12B and 12C, the radiating elements of group B are both vertically polarized and horizontally polarized in a direction inclined by 19 ° from the direction perpendicular to the array antenna 1 (radiation direction). The radio wave from 10 is strong. A grating lobe appears in the horizontal direction of 40 °.

As described with reference to FIG. 4, the radio wave from the radiating element 10 of group D is strong in the 45 ° direction from the direction perpendicular to the array antenna 1 (radiation direction) from both the horizontal direction and the vertical direction. Get out. As shown in FIGS. 12B and 12C, both vertical polarization and horizontal polarization are tilted by 19 ° in the vertical direction from the direction (radiation direction) perpendicular to the array antenna 1 and further tilted by ± 19 ° in the horizontal direction. In the direction, the radio wave from the radiating element 10 of group D is strong.
The radio wave from the radiation element 10 of the group D appears in a range (null) of an angle where the radio wave from the radiation element 10 of the group B is weak. Further, the radio waves from groups A and C are not shown in the figure because they are in the null position in the vertical direction as shown in FIG.
That is, the radio wave from the radiation element 10 of the group B and the radio wave from the radiation element 10 of the groups A, C, and D have a low correlation.

FIG. 13 is a diagram illustrating the gain [dB] in the vertical direction (in the vertical plane) at 0 ° in the horizontal direction. 13A illustrates the direction of radio waves, FIG. 13B illustrates the gain for each angle in the vertical polarization, and FIG. 13C illustrates the gain for each angle in the horizontal polarization.
As shown in FIG. 13A, the gain of radio waves in the vertical direction (in the vertical plane) was obtained by simulation at 0 ° in the horizontal direction of the array antenna 1.
As described with reference to FIG. 4, radio waves from the radiating element 10 of group A are strongly emitted in a direction (radiation direction) perpendicular to the array antenna 1. As shown in FIGS. 13B and 13C, the radio wave from the radiating element 10 of group A is strongly emitted in the direction (radiation direction) perpendicular to the array antenna 1 in both vertical polarization and horizontal polarization. Yes. A grating lobe appears in the horizontal direction of 40 °.

Then, as described with reference to FIG. 4, radio waves from the radiating element 10 of group B are strongly emitted in a direction inclined from the direction perpendicular to the array antenna 1 (radiation direction) to the vertical direction. As shown in FIGS. 13B and 13C, the radiating element 10 of the group B is located at 20 ° perpendicular to the direction (radiation direction) perpendicular to the array antenna 1 for both the vertical polarization and the horizontal polarization. There is a strong radio wave from.
The radio wave from the radiation element 10 of the group B appears in a range (null) where the radio wave from the radiation element 10 of the group A is weak. In addition, the radio waves from the groups C and D are not shown in the drawing because they are in the null position in the horizontal direction as shown in FIG.
That is, the radio wave from the radiating element 10 of group A and the radio wave from the radiating element 10 of groups B, C, and D have a low correlation.

FIG. 14 is a diagram showing the gain [dB] in a plane inclined in the horizontal direction of 19 °. 14A illustrates the direction of radio waves, FIG. 14B illustrates the gain for each angle in vertical polarization, and FIG. 14C illustrates the gain for each angle in horizontal polarization.
As shown in FIG. 14A, the gain of the radio wave in the vertical direction in the plane inclined at 19 ° in the horizontal direction from the direction (radiation direction) perpendicular to the array antenna 1 was obtained by simulation.
As described with reference to FIG. 4, the radio wave from the radiation element 10 of the group C is strongly emitted in the direction inclined in the horizontal direction from the direction perpendicular to the array antenna 1 (radiation direction). As shown in FIGS. 14B and 14C, both vertically polarized waves and horizontally polarized waves are inclined in the direction (radial direction) perpendicular to the array antenna 1 by 19 ° in the horizontal direction (vertical direction 0 °). , The radio wave from the radiation element 10 of group C is strong. A grating lobe appears in the vertical direction of 40 °.

As described with reference to FIG. 4, the radio wave from the radiating element 10 of group D is strong in the 45 ° direction from the direction perpendicular to the array antenna 1 (radiation direction) from both the horizontal direction and the vertical direction. Get out. As shown in FIGS. 14B and 14C, both the vertical polarization and the horizontal polarization are inclined by 19 ° in the horizontal direction and further by ± 19 ° in the vertical direction from the direction perpendicular to the array antenna 1 (radiation direction). In the direction, the radio wave from the radiating element 10 of group D is strong.
The radio wave from the radiation element 10 of the group D appears in a range (null) where the radio wave from the radiation element 10 of the group C is weak. Further, the radio waves from groups A and B are not shown in the figure because they are in the null position in the horizontal direction as shown in FIG.
That is, the correlation between the radio wave from the radiating element 10 of group C and the radio wave from the radiating element 10 of groups A, B, and D is low.

  As described above, radio waves from groups A, B, C, and D have a low correlation with each other and can be used as independent paths. In other words, the array antenna 1 can radiate radio waves from eight signal inputs when polarized waves are applied.

  As described in the first embodiment and the second embodiment, the phase can be changed by 180 ° by setting the feeding direction of the radiating element 10 to the opposite phase. Therefore, the power feeding circuit 20 can be configured easily.

In the first embodiment and the second embodiment, the array antenna 1 uses the radiating elements 10 of groups A, B, C, and D. However, the array antenna 1 may be configured using at least two of the radiating elements 10 of the groups A, B, C, and D.
That is, the array antenna 1 is a plurality of groups each including a plurality of radiating elements 10 arranged in a matrix so as to be an even number in a direction crossing each other (here, the horizontal direction and the vertical direction). Signals of systems different from each other are fed to the group, and the radiating elements 10 in the plurality of groups are adjacent to each other in the feeding direction, in the horizontal direction, in the vertical direction, or both, without overlapping. It is only necessary to set whether the feeding direction is different between the ten.
Therefore, the radiating element 10 of the array antenna 1 can be 2 × 4, 4 × 2, 4 × 4, 4 × 6, 6 × 4, 6 × 6, etc., even if it is not 8 × 8.

  In addition, although the power feeding circuit 20 is composed of a PCB in which a conductor film (metal foil) is formed on both surfaces of the dielectric substrate 11, when two PCBs are provided, the conductor film is provided in three layers. You may comprise with PCB. A conductor that feeds power to the radiating element 10 may be configured by using the central conductor film as a reference conductor and the conductor films on both sides.

Furthermore, the numerical values shown in the second embodiment are merely examples, and may be changed according to the wavelength of the radio wave to be used.
In the first embodiment and the second embodiment, the polarization of the radiating element 10 is a vertical polarization and a horizontal polarization. However, the direction of the polarization is not limited to these, for example, ± 45 ° It may be a wave or a circularly polarized wave.
In addition, various modifications may be combined without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Array antenna 2, 2A, 2B ... Main lobe 10, 10A, 10B ... Radiation element, 11 ... Dielectric substrate, 12, 12A, 12B, 12C, 12D, 12E, 13 ... Conductor, 20 ... Feeding circuit, 21 ... Hybrid circuit, 22 ... Delay line, 30 ... Housing, 40 ... Cover

For this purpose, the array antenna to which the present invention is applied has a plurality of radiations arranged in a matrix so as to be an even number in each of the first direction and the second direction intersecting the first direction. A plurality of groups each having an element are provided, and each group constituting the plurality of groups is fed with signals of different systems, and the plurality of radiating elements of each group are adjacent to each other without overlapping between the groups. the radiation element pairs, and characterized in that one feeding direction signal is fed the same, first towards direction and feeding direction in either or both of the second direction is set opposite or in each other To do.
In such an array antenna, the radiating element pair in which the feeding directions are set to be opposite to each other in the plurality of radiating elements of each group, the phase of the radio wave radiated from one radiating element to the other radiating element is 180 °. It can be characterized by being arranged to change .

Claims (5)

A plurality of groups each having a plurality of radiating elements arranged in a matrix so as to be an even number in each of the first direction and the second direction intersecting the first direction;
Each group constituting the plurality of groups is fed with signals from different systems,
The plurality of radiating elements in each group do not overlap between the groups, and in the adjacent radiating element pairs, the feeding direction in which a signal is fed is the same, or the first direction and the second direction The array antenna is characterized in that the feeding direction is set to be opposite to each other in either or both.   The radiating element pair in which the feeding directions are set to be opposite to each other in the plurality of radiating elements of each group, wherein one radiating element is inverted with respect to the other radiating element. 2. The array antenna according to 1.   The array antenna according to claim 1 or 2, wherein the plurality of radiating elements of each group are alternately arranged between two or more groups.   4. The system according to claim 1, wherein the plurality of radiating elements in at least one group of the respective groups are polarization shared, and signals of different systems are fed by the polarization. The array antenna described in 1. A power feeding circuit that feeds power to the plurality of radiating elements of each group;
A housing that is provided on the side opposite to the side that radiates radio waves of the plurality of radiating elements of each group, and that houses the plurality of radiating elements of each group and the feeding circuit;
A cover that is provided on a side of the plurality of radiating elements of each group that radiates radio waves and is combined with the housing to protect the plurality of radiating elements of the group and the power feeding circuit; The array antenna according to any one of claims 1 to 4, characterized in that:

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