JPH11298238A - Antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure high communication quality while simplifying switching control in the beam direction of an antenna concerning an antenna system to be utilized for radio communication in a room or the like. SOLUTION: This system is provided with an antenna array 10, first 90 deg. phase shifter 33, second 90 deg. phase shifter 34, first hybrid circuit 31 connecting a first output terminal 21 with a first element antenna 51 and connecting a second output terminal 22 through the first 90 deg. phase shifter 33 to a second element antenna 52, second hybrid circuit 32 connecting a third output terminal 23 through the second 90 deg. phase shifter 34 to a third element antenna 53 and connecting a fourth output terminal 24 with a fourth element antenna 54, and switching means 36 for selectively connecting a power feeding input terminal 30 to a fifth output terminal 25 and a sixth output terminal 26 while connecting a first input terminal 11 of the first hybrid circuit 31 to the fifth output terminal 25 and connecting a second input terminal 12 of the first hybrid circuit 31 and a third input terminal 13 of the second hybrid circuit 32 to the sixth output terminal 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device which can be used for wireless communication indoors, and more particularly to an antenna device capable of switching directional characteristics.

[0002]

2. Description of the Related Art A wireless communication system for performing wireless communication indoors is disclosed in, for example, a document "T. Tsutsumi and K. Ujiie," Alta.
ir Products of 19GHz Radio LAN System, "MWE'93 Micr
owaveWorkshop Digest, pp. 201-206, 1993. " In this type of wireless communication system, TDMA (Time Division Multiple Acceleration) is performed between a base station and a terminal station.
ess: time division multiple access) communication. As shown in FIG. 9, a sector antenna capable of selecting a beam direction is used for each of a base station and a terminal station.

In the example shown in FIG. 9, a base station and a terminal station use sector antennas capable of selecting six types of beam directions. Further, by switching the direction of the beam of the sector antenna by the base station and the terminal station, the transmission path between them can be variously changed.

A transmission path between a base station and a terminal station includes not only a direct wave but also a path using a reflected wave. By switching the beam direction of each sector antenna,
A transmission path with good communication quality is selected. When the base station and the terminal station use sector antennas that can select six types of beam directions, 36 transmission paths can be selected by combining the beam directions of these sector antennas.

Further, by using a table in which the relationship between the combination of the beam direction of each sector antenna and the communication quality is recorded in advance, it becomes easy to select a transmission path having good quality. Therefore, when a failure occurs in the transmission path in use, the transmission path can be switched to a high-quality transmission path in a short time. In indoor wireless communication, communication quality greatly changes depending on the positions of a base station and a terminal station due to the influence of a reflected wave generated on an indoor wall surface. Therefore, it is necessary to improve communication quality by switching transmission paths as shown in FIG.

[0006]

However, when a sector antenna capable of selecting a large number of beam directions is used, it is inevitable that the switching control of the beam directions becomes complicated. Also, since it is difficult to reduce the size of a sector antenna from which a large number of beam directions can be selected, it is difficult to reduce the size of a base station and a terminal station by using this type of antenna.

Further, it is not possible to suppress the round-trip reflected wave between the walls only by selecting the beam direction of the antenna. Therefore, in order to further increase the transmission speed, it is necessary to further reduce the beam width of the sector antenna. Therefore, it is necessary to further increase the number of sectors and the size of the antenna. The present invention relates to an antenna device used for wireless communication in a room or the like,
An object is to enable simplification of switching control of an antenna beam direction and to ensure high communication quality.

[0008]

According to a first aspect of the present invention, there is provided an antenna device comprising: an antenna array in which a first element antenna, a second element antenna, a third element antenna, and a fourth element antenna are arranged in a predetermined direction; 1 90 degree phase shifter and 2nd
, A first input terminal, a second input terminal,
A first output terminal and a second output terminal, wherein the first output terminal is connected to the first element antenna;
Is connected to the second terminal through the first 90-degree phase shifter.
A first hybrid circuit connected to the element antenna;
A third input terminal, a fourth input terminal, a third output terminal, and a fourth output terminal, wherein the third output terminal is the second output terminal;
A second hybrid circuit connected to the third element antenna via the 90-degree phase shifter, the fourth output terminal of which is connected to the fourth element antenna;
And a sixth output terminal, a fifth input terminal of the first hybrid circuit is connected to the fifth output terminal, and a sixth output terminal of the first hybrid circuit is connected to the sixth output terminal. Switching means for connecting the second input terminal and the third input terminal of the second hybrid circuit, and selectively connecting the power supply input terminal to the fifth output terminal and the sixth output terminal. It is characterized by.

A case where this antenna device is used for transmission will be described. When the switching means is in the first selection state, the power applied to the power supply input terminal is applied from the fifth output terminal to the first input terminal of the first hybrid circuit. This power is supplied from the first output terminal of the first hybrid circuit to the first element antenna. at the same time,
90 appearing at the second output terminal of the first hybrid circuit
The phase-shifted power passes through the first 90-degree phase shifter to the second
Power is supplied to the element antenna.

That is, when the switching means is in the first selected state, power is supplied to the first element antenna and the second element antenna in opposite phases. On the other hand, when the switching means is in the second selection state, the power applied to the power supply input terminal is the sixth power.
Are applied to the second input terminal of the first hybrid circuit and the third input terminal of the second hybrid circuit.

[0011] The power applied to the second input terminal of the first hybrid circuit is supplied from the first output terminal to the first element antenna. Since the phase at the first output terminal is shifted by 90 degrees, the phase is shifted by 90 degrees with respect to the phase of the power supply input terminal.
The shifted power is supplied to the first element antenna. Also,
Power appearing at the second output terminal of the first hybrid circuit is fed to the second element antenna via the first 90-degree phase shifter. Therefore, power having a phase shifted by 90 degrees with respect to the phase of the feed input terminal is fed to the second element antenna.

The electric power applied to the third input terminal of the second hybrid circuit is supplied from the third output terminal to the third element antenna via the second 90-degree phase shifter. Therefore, the phase of the power fed to the third element antenna is shifted by 90 degrees from the phase of the feed input terminal. Also, the second
The power appearing at the fourth output terminal of the hybrid circuit of
Power is supplied to the fourth element antenna. Since power having a phase shifted by 90 degrees appears at the fourth output terminal, power having a phase shifted by 90 degrees with respect to the phase of the feed input terminal is supplied to the fourth element antenna.

That is, when the switching means is in the second selected state, the power having a phase shifted by 90 degrees with respect to the phase of the feed input terminal is supplied to the first element antenna, the second element antenna, and the third element antenna.
Power is supplied to the element antenna and the fourth element antenna. That is, the first element antenna, the second element antenna, the third element antenna, and the fourth element antenna are fed in phase with each other.

In this antenna device, the directional characteristics are switched by switching the selection state of the switching means. Therefore, this antenna device can be used as a sector antenna having two types of beam directions. In particular, the two types of beam directions of the antenna device have characteristics that are effective for obtaining high transmission quality in indoor wireless communication, as described later.

That is, according to the present invention, higher transmission quality can be obtained as compared with a conventional sector antenna in which two types of beam directions can be selected. Actually, transmission quality equivalent to that of a conventional sector antenna in which three types of beam directions can be selected is obtained. Therefore, the selection control of the beam direction can be simplified.
Further, the power supply circuit can be realized with a simple configuration. Claim 2
2. The antenna device according to claim 1, wherein a sixth output terminal of said switching means is connected to a second input terminal of said first hybrid circuit and a third input terminal of said second hybrid circuit via a distributor. It is characterized by being connected with.

The electric power appearing at the sixth output terminal of the switching means is divided into two systems by a distributor, one of which is applied to the second input terminal of the first hybrid circuit, and the other is applied to the second hybrid circuit. Applied to the third input terminal. According to a third aspect of the present invention, in the antenna device according to the first aspect, the switching means is provided with a fifth input terminal by using a double pole double throw (DPDT: Doppler).
Double Pole Double Throw) switch.
And a terminating device connected to the input terminal.

When the double pole double throw switch is in the first selected state, the second input terminal of the first hybrid circuit connected to the sixth output terminal and the third input terminal of the second hybrid circuit. Is terminated by a terminator connected to the fifth input terminal. When the double-pole double-throw switch is in the second selected state, the first input terminal of the first hybrid circuit connected to the fifth output terminal is a terminal device connected to the fifth input terminal. Terminated.

According to a fourth aspect of the present invention, in the antenna device according to the first aspect, a termination device is connected to a fourth input terminal of the second hybrid circuit. Claim 5
2. The antenna device according to claim 1, wherein the antenna array, a first 90-degree phase shifter, a second 90-degree phase shifter,
It is characterized in that the first hybrid circuit, the second hybrid circuit, and the switching means are made of a dielectric substrate and a foil-shaped conductive metal material adhered on the dielectric substrate.

The antenna array, the first 90-degree phase shifter, and the second 90-degree phase shifter are formed by a planar circuit using a dielectric substrate and a foil-shaped conductive metal material adhered on the dielectric substrate. ,
By configuring the first hybrid circuit, the second hybrid circuit, and the switching unit, the thickness of the entire antenna device can be reduced. Claim 6 is the antenna device according to claim 5, wherein the first hybrid circuit and the second
Wherein the hybrid circuit is constituted by a branch line type hybrid circuit or a rat race circuit.

The branch line type hybrid circuit or rat race circuit can be formed as a planar circuit using a dielectric substrate and a foil-like conductive metal material adhered on the dielectric substrate. According to a seventh aspect, in the antenna device according to the first aspect, the first element antenna, the second element antenna, the third element antenna, and the fourth element antenna are arranged at equal intervals.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of an example of the embodiment are shown in FIGS. This form corresponds to all claims. FIG. 1 is a perspective view showing the appearance of the antenna device.
FIG. 2 is a longitudinal sectional view showing one element antenna included in the antenna device of FIG. FIG. 3 is a perspective view showing an actual arrangement example of the antenna device.

FIG. 4 is a block diagram showing a configuration of a feeder circuit of the antenna device of FIG. FIG. 5 is a graph showing a directional characteristic of a horizontal plane of the antenna device of FIG. FIG.
2 is a graph showing a distribution of a reception level deviation at each position on a floor when a beam B1 of the antenna device of FIG. 1 is used. FIG. 7 is a graph showing the distribution of the reception level deviation at each position on the floor when the beams B2 and B3 of the antenna device of FIG. 1 are used. FIG. 8 is a graph showing the distribution of the reception level deviation at each position on the floor when the two types of directional characteristics of the antenna device of FIG. 1 are switched and used.

In this embodiment, the antenna array, the first 90-degree phase shifter, the second 90-degree phase shifter, the first hybrid circuit, the second hybrid circuit, and the switching means are each provided with an antenna. Array 10, 90 degree phase shifter 3
3, 90 degree phase shifter 34, 90 degree hybrid circuit 31,
90 degree hybrid circuit 32 and double pole double throw switch 36
Corresponding to

Also, the first element antenna and the second element antenna of the first aspect are provided.
The element antenna, the third element antenna, and the fourth element antenna correspond to the element antenna 51, the element antenna 52, the element antenna 53, and the element antenna 54, respectively. Further, the first input terminal, the second input terminal, and the third
, A fourth input terminal, a first output terminal, a second output terminal, a third output terminal, a fourth output terminal, a fifth output terminal, and a sixth output terminal are input terminals, respectively. 11,
These correspond to the input terminal 12, the input terminal 13, the input terminal 14, the output terminal 21, the output terminal 22, the output terminal 23, the output terminal 24, the output terminal 25, and the output terminal 26.

The distributor of claim 2 corresponds to the distributor 35. The fifth input terminal and the terminating device in claim 3 correspond to the input terminal 15 and the terminating device 37, respectively. The terminating device according to claim 4 corresponds to the terminating device 38. The antenna device of this embodiment is designed on the assumption that it is used as an antenna of a base station of a system that performs wireless communication indoors. This antenna device is installed on a side wall near the ceiling of a room, for example, as shown in FIG. 3, and is used as an antenna device of a base station that performs wireless communication with a terminal station placed on the floor or on a desk. it can.

As shown in FIG. 1, the antenna device is a planar antenna and includes eight element antennas 51 to 54 and 61 to 64 formed on a dielectric substrate 44. The eight element antennas 51 to 54 and 61 to 64 are all microstrip antennas having the same configuration.

The element antenna 51 is, as shown in FIG.
Circular patch 4 arranged on the front surface of dielectric substrate 44
1, the base plate 42 and the coaxial cable 4 arranged on the back surface
3. The circular patch 41 and the base plate 42
It is formed of a conductive metal foil attached to the surface of the dielectric substrate 44. The circular patch 41 is formed in a circular shape as shown in FIG. The feeding point of the antenna is set at a position slightly shifted from the center of the circular patch 41. The other element antennas 52 to 54 and 61 to 64 have the same configuration as that of FIG.

As shown in FIG. 1, the element antennas 51 to 5
4 and 61 to 64 are arranged at a constant pitch. In this example, the pitch of the element antennas is set to 0.4λo (λo is a free space wavelength of a frequency used by the antenna) in both directions of the X axis and the Y axis. In this example, as shown in FIGS. 1 and 3, four element antennas 51 to 54 extend in the X-axis direction corresponding to the horizontal direction of the antenna device.
(Or 61 to 64) are arranged, and two element antennas 51 and 61 are arranged in the Z-axis direction corresponding to the vertical direction of the antenna device.

Although the four element antennas 51 to 54 arranged in the X-axis direction must be provided, the number of antenna elements arranged in the Z-axis direction may be one. By arranging a plurality of element antennas in the Z-axis direction, it is easy to design and adjust the beam width and tilt angle of the directional characteristics in the vertical direction. As shown in FIG. 4, the electric circuit of the antenna device includes an antenna array 10 including element antennas 51 to 54 and 61 to 64 and a feed circuit 100.

As shown in FIG. 4, an element antenna 51 and an element antenna 61 are connected to each other in parallel, an element antenna 52 and an element antenna 62 are connected to each other in parallel,
The element antenna 53 and the element antenna 63 are connected to each other in parallel, and the element antenna 54 and the element antenna 64 are connected to each other in parallel. The power supply circuit 100 is provided with two 90-degree hybrid circuits 31, 32, two 90-degree phase shifters 33, 34, a distributor 35, a double-pole double-throw switch 36, and two terminating devices 37, 38.

Here, for the sake of convenience, it is assumed that this antenna device is used as a transmitting antenna, and
0 Input and output names are assigned to the terminals of each device inside. The double-pole double-throw switch 36 controls the external
You can select the type of status. In the first selection state, the input terminal 36a and the output terminal 25 are connected, and the input terminal 15 and the output terminal 26 are connected. In the second selection state, the input terminal 36a and the output terminal 26 are connected, and the input terminal 15 and the output terminal 25 are connected.

The power supply input terminal 30 is a double pole double throw switch 3
6 input terminal 36a. The input terminal 15 of the double-pole double-throw switch 36 is terminated by a termination device 37. The output terminal 25 of the double-pole double-throw switch 36 is connected to the input terminal 11 of the 90-degree hybrid circuit 31.
The output terminal 26 of the double-pole double-throw switch 36 is branched into two systems by a distributor 35 and connected to the input terminal 12 of the 90-degree hybrid circuit 31 and the input terminal 13 of the 90-degree hybrid circuit 32. 90 degree hybrid circuit 32
Are terminated by a terminating device 38.

In the 90-degree hybrid circuit 31,
The signal at the input terminal 11 and the signal at the output terminal 21 have the same phase. Further, the signal of the input terminal 12 and the signal of the output terminal 22 have the same phase. 90 degree hybrid circuit 3
In 2, the signal at the input terminal 13 and the signal at the output terminal 23 have the same phase, and the signal at the input terminal 14 and the signal at the output terminal 24 have the same phase.

Output terminal 2 of 90-degree hybrid circuit 31
Element antennas 51 and 61 are connected to 1. 9
The output terminal 22 of the 0-degree hybrid circuit 31 is connected to the element antennas 52 and 62 via a 90-degree phase shifter 33. The 90-degree phase shifter 33 has 9 terminals between its input and output.
Generates a 0 degree phase difference. In addition, element antennas 53 and 63 are connected to an output terminal 23 of the 90-degree hybrid circuit 32 via a 90-degree phase shifter 34. The 90-degree phase shifter 34 generates a 90-degree phase difference between its input and output. Element antennas 54 and 64 are connected to the output terminal 24 of the 90-degree hybrid circuit 32.

Next, the operation of the power supply circuit 100 shown in FIG. 4 will be described. First, assume that the double-pole double-throw switch 36 is set to the first selected state. In this case, the power input from the power supply input terminal 30 is
It is applied to the input terminal 11 of the 0-degree hybrid circuit 31. In this case, the input terminal 12 of the 90-degree hybrid circuit 31 and the input terminal 13 of the 90-degree hybrid circuit 32
Is terminated by a terminating device 37 via a distributor 35 and a double pole double throw switch 36.

Input terminal 1 of 90-degree hybrid circuit 31
1 is split into two systems inside the 90-degree hybrid circuit 31, and the output terminal 21 and the output terminal 2
Appears in 2. Output terminal 2 of 90-degree hybrid circuit 31
At 1, power in phase with the input terminal 11 appears. This power is supplied to the element antennas 51 and 61. The output terminal 22 of the 90-degree hybrid circuit 31 has an input terminal 1
A power having a phase difference of 90 degrees with respect to the power of 1 appears,
This power is further supplied to the element antennas 52 and 62 via the 90-degree phase shifter 33.

The phase of the power applied to the element antennas 51 and 61 is the same as that of the power supply input terminal 30. The power applied to the element antennas 52 and 62 changes the phase by 90 degrees inside the 90-degree hybrid circuit 31 and further
Since the phase is changed by 90 degrees by the 0-degree phase shifter 33, a 180-degree phase difference occurs with respect to the power supply input terminal 30.

Therefore, the element antenna 51 and the element antenna 52 are excited with powers having phases opposite to each other. When the double-pole double-throw switch 36 is set to the first selected state, power is not supplied to the element antennas 53, 54, 63, and 64. Next, it is assumed that the double-pole double-throw switch 36 is set to the second selected state. In this case, the power input from the power supply input terminal 30 is supplied from the output terminal 26 via the distributor 35 to the input terminal 1 of the 90-degree hybrid circuit 31.
It is applied to the input terminal 13 of the 2 and 90 degree hybrid circuit 32.

In this case, the input terminal 11 of the 90-degree hybrid circuit 31 is terminated by the terminating device 37 via the double pole double throw switch 36. The power applied to the input terminal 12 of the 90-degree hybrid circuit 31 is split into two systems inside the 90-degree hybrid circuit 31 and appears at the output terminal 21 and the output terminal 22.

Output terminal 2 of 90-degree hybrid circuit 31
At 1, power having a phase difference of 90 degrees with respect to the input terminal 12 appears. This power is supplied to the element antennas 51 and 61. In addition, at the output terminal 22 of the 90-degree hybrid circuit 31, power having the same phase as that of the input terminal 12 appears, and this power is transmitted via the 90-degree phase shifter 33 to the element antennas 52 and 62.
Power is supplied to

The power applied to the element antennas 51 and 61 has a phase difference of 90 degrees inside the 90-degree hybrid circuit 31, and thus has a phase difference of 90 degrees with respect to the feed input terminal 30. In addition, the power applied to the element antennas 52 and 62 has a phase difference of 90 degrees due to the 90-degree phase shifter 33, and thus has a phase difference of 90 degrees with respect to the feed input terminal 30.

The power applied to the input terminal 13 of the 90-degree hybrid circuit 32 is split into two systems inside the 90-degree hybrid circuit 32 and appears at the output terminal 23 and the output terminal 24.

Output terminal 2 of 90-degree hybrid circuit 32
At 3, power having the same phase as that of the input terminal 13 appears, and this power is supplied to the element antennas 53 and 63 via the 90-degree phase shifter 34. At the output terminal 24 of the 90-degree hybrid circuit 32, power having a phase difference of 90 degrees with respect to the input terminal 13 appears, and this power is supplied to the element antennas 54 and 64.

The power applied to the element antennas 53 and 63 has a phase difference of 90 degrees with the 90-degree phase shifter 34, and thus has a phase difference of 90 degrees with respect to the feed input terminal 30. In addition, the power applied to the element antennas 52 and 62 has a phase difference of 90 degrees inside the 90-degree hybrid circuit 32, and thus has a phase difference of 90 degrees with respect to the feed input terminal 30.

That is, when the double-pole double-throw switch 36 is set to the second selected state, the element antennas 51 to 54
And 61 to 64 are excited with the same phase power.
Therefore, by switching the selection state of the double-pole double-throw switch 36, it is possible to select whether the phase of the power supplied to the antenna array 10 is reversed or in-phase. FIG. 5 shows the directional characteristics of the antenna device shown in FIG. 1 in the horizontal plane. FIG. 5 shows two types of directional characteristics that can be selected by switching the selection state of the double-pole double-throw switch 36. In FIG. 5, the directivity in each direction of the horizontal plane is shown with the Y-axis direction perpendicular to the substrate surface of the antenna device as 0 degree.

Referring to FIG. 5, it can be seen that the directivity of the antenna device in the horizontal plane changes greatly between in-phase excitation and anti-phase excitation. That is, this antenna apparatus can be used as an antenna similar to a two-sector antenna by switching the selection state of the double pole double throw switch 36. Although not shown, all the components of the power supply circuit 100 shown in FIG. 4 are configured as planar circuits using microstrip lines. Also, in order to realize a planar circuit, the 90-degree hybrid circuits 31 and 32 are configured as branch line type hybrid circuits. A rat race circuit may be used instead of the branch line hybrid circuit.

In this example, all the components of the power supply circuit 100 are formed of microstrip lines without crossing the lines on one substrate. For this reason, the entire antenna device is configured to be thin. Since this type of antenna device can be manufactured only by a printing technique, it is suitable for mass production, and at the same time, has an advantage that cost reduction can be easily realized.

A simulation of communication quality was performed on the assumption that the antenna apparatus shown in FIG. 1 is actually applied to a base station of an indoor wireless communication system. Figure 6 shows the results.
7 and 8. For comparison, FIGS. 10 and 11 show the results when the conventional two-sector antenna and three-sector antenna are used. In this simulation, the length in the Y-axis direction is 20 m, the width in the X-axis direction is 20 m, and the height in the Z-axis direction is 3 using the frequency of the microwave band.
It is assumed that the antenna device of FIG. 1 is installed as a base station antenna on the wall of a room m as shown in FIG.

Also, it is assumed that a single element antenna is arranged on the floor as a communication partner terminal station. Then, the communication speed was set to 40 Mbps, and the characteristic of the in-band deviation, which is one of the judgments of the communication availability, was analyzed using the ray tracing method. That is, FIGS. 6 to 8 and FIGS. 10 and 11 show the deviation of the reception level at each point in the room. In addition, circular polarization was used for communication between the antenna devices, and the calculation was performed assuming that the horizontal beam width of the antenna device of the terminal station was 60 degrees. Further, the ratio between the area of the place where the in-band deviation is within a predetermined threshold and the total area of the room is shown as the place ratio.

FIG. 6 shows a case where only the beam B1 shown in FIG. 5 is used. FIG. 7 shows a case where only the V-shaped beams B2 and B3 shown in FIG. 5 are used. FIG. 8 shows a case where a preferred directional characteristic is selected according to a place and two types of beams (B1, B2, B3) are used.

Referring to FIGS. 6 and 7, it can be seen that the two types of beams differ from each other in the range where the in-band deviation is small. Also, two beams (B
2, B3) do not interfere with each other. Further, referring to FIG. 8, two types of beams (B1, B2, B3)
, The final high location ratio (68
%) Can be obtained. The location ratio of 68% is equivalent to the transmission quality in the case where a conventional three-sector antenna having a beam width of 60 degrees is used.

In the conventional example shown in FIGS. 10 and 11, the conditions other than the antenna of the base station are determined in the same manner as in FIGS. In FIG. 10, the number of sectors of the antenna of the base station is set to 2, and the horizontal beam width of the antenna of the base station is set to 90 degrees. In FIG. 11,
The number of sectors of the base station antenna is set to 3, and the horizontal beam width of the base station antenna is set to 60 degrees.

In the example of FIG. 10, the location ratio for realizing the in-band deviation of 7 dB or less is about 60%, which means that the communication quality is not practically sufficient. In addition, in the example of FIG. 11, the location ratio is 71%, which indicates that communication can be performed with practically sufficient quality.

[0054]

As described above, the antenna device of the present invention is an antenna device capable of switching two or more types of beams, and two types of in-phase excitation and opposite-phase excitation of the antenna can be selected by switching. Thus, two types of beams, a narrow beam in the front direction in the horizontal plane and a V-shaped beam having a null formed in the front, can be selected with a simple configuration.

Therefore, when the antenna device is installed on an indoor wall, it is possible to irradiate the interior of the room with a narrow beam and irradiate both corners of the room with a V-shaped beam. Although it is an antenna, transmission quality equivalent to an antenna of three sectors can be ensured.

Further, by constituting each element of the element antenna and the feed circuit with a dielectric substrate and a foil-shaped conductive metal material adhered thereon, the whole antenna device can be constructed in a plane. . Thus, the antenna device can be manufactured only by the printing technique. Therefore,
Since it is suitable for mass production, there is an advantage that cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of an antenna device.

FIG. 2 is a longitudinal sectional view showing one element antenna included in the antenna device of FIG.

FIG. 3 is a perspective view showing an actual arrangement example of the antenna device.

FIG. 4 is a block diagram illustrating a configuration of a feed circuit of the antenna device of FIG. 1;

FIG. 5 is a graph showing a directional characteristic of a horizontal plane of the antenna device of FIG. 1;

6 is a graph showing a distribution of a reception level deviation at each position on the floor when the beam B1 of the antenna device of FIG. 1 is used.

FIG. 7 is a graph showing a distribution of a reception level deviation at each position on the floor when the beams B2 and B3 of the antenna device of FIG. 1 are used.

8 is a graph showing a distribution of a reception level deviation at each position on the floor surface when two types of directional characteristics of the antenna device of FIG. 1 are switched and used.

FIG. 9 is a plan view showing an example of a transmission path formed by a conventional wireless communication device.

FIG. 10 is a graph showing a distribution of a reception level deviation at each position on the floor when a conventional two-sector antenna is used.

FIG. 11 is a graph showing a distribution of a reception level deviation at each position on the floor when a conventional three-sector antenna is used.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Antenna array 11, 12, 13, 14, 15, 36a Input terminal 21, 22, 23, 24, 25, 26 Output terminal 30 Feeding input terminal 31, 32 90 degree hybrid circuit 33, 34 90 degree phase shifter 35 Distribution Device 36 Double-pole double-throw switch 37, 38 Termination device 41 Circular patch 42 Ground plane 43 Coaxial cable 44 Dielectric substrate 51, 52, 53, 54, 61, 62, 63, 64 Element antenna 100 Feeding circuit

Claims (7)

[Claims] A first element antenna, a second element antenna,
An antenna array in which a third element antenna and a fourth element antenna are arranged side by side in a predetermined direction; a first 90-degree phase shifter; a second 90-degree phase shifter; a first input terminal; , A first output terminal, and a second output terminal, wherein the first output terminal is the first output terminal.
A first hybrid circuit connected to an element antenna, the second output terminal being connected to the second element antenna via the first 90-degree phase shifter; a third input terminal; An input terminal, a third output terminal, and a fourth output terminal, wherein the third output terminal is connected to the second output terminal.
A second hybrid circuit connected to the third element antenna via the 90-degree phase shifter, and the fourth output terminal is connected to the fourth element antenna; a power supply input terminal and a fifth output terminal And a sixth output terminal, wherein a fifth input terminal of the first hybrid circuit is connected to the fifth output terminal, and a second input terminal of the first hybrid circuit is connected to the sixth output terminal. Switching means for connecting the terminal and the third input terminal of the second hybrid circuit, and selectively connecting the power supply input terminal to the fifth output terminal and the sixth output terminal. Antenna device. 2. The antenna device according to claim 1, wherein
An antenna device, wherein a sixth output terminal of the switching means is connected to a second input terminal of the first hybrid circuit and a third input terminal of the second hybrid circuit via a distributor. 3. The antenna device according to claim 1, wherein
An antenna device, wherein the switching means comprises a double pole double throw switch having a fifth input terminal, and a terminating device is connected to the fifth input terminal. 4. The antenna device according to claim 1, wherein
An antenna device, wherein a terminating device is connected to a fourth input terminal of the second hybrid circuit. 5. The antenna device according to claim 1, wherein
The antenna array, a first 90-degree phase shifter, a second 90-degree phase shifter;
An antenna device wherein the phase shifter, the first hybrid circuit, the second hybrid circuit, and the switching means are constituted by a dielectric substrate and a foil-shaped conductive metal material adhered on the dielectric substrate. . 6. The antenna device according to claim 5, wherein
An antenna device, wherein the first hybrid circuit and the second hybrid circuit are configured by a branch line type hybrid circuit or a rat race circuit. 7. The antenna device according to claim 1, wherein
An antenna device, wherein the first element antenna, the second element antenna, the third element antenna, and the fourth element antenna are arranged at equal intervals.