JP2000201020A - Antenna device - Google Patents

Abstract

(57) [Problem] Conventionally, there has been a problem that there are few design parameters for determining electric performance, and it is difficult to design a beam width of an antenna to a desired value at two frequencies. SOLUTION: A linear primary radiator 51 operating at a frequency f1 and a linear primary radiator 52 operating at a frequency f2 are provided.
And a V-shaped reflector 1 for reflecting radio waves of frequency f1, and a V-shaped reflector 2 for transmitting radio waves of frequency f1 and reflecting radio waves of frequency f2. [Effect] It becomes easy to design the beam width in the horizontal plane of the antenna to a desired value at two frequencies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-frequency antenna device used for a radio communication base station or the like.

[0002]

2. Description of the Related Art A conventional antenna device will be described with reference to the drawings. FIG. 9 is a diagram illustrating a configuration of a conventional antenna device described in, for example, “IEICE Technical Report A / P97-73 (1997-07)”.

FIG. 9 shows the structure of a dual frequency base station antenna designed to make the antenna as thin as possible. The tip of a normal corner reflector antenna is bent and housed in a radome.

Since the base station antenna has an array antenna structure, the mechanical strength is given to the cylindrical radome. The dual-frequency radiating element is a dipole antenna with a parasitic element.

That is, a dual-frequency radiating element is used as a primary radiator, and a reflector based on a corner reflector antenna structure is used.

[0006] A corner reflector antenna emits vertically polarized radio waves at two frequencies. In order to make the beam width the same at the two frequencies, the opening angle of the corner reflector, the length of the reflector, and the position of the primary radiator from the corner are changed. With few design parameters, it is not easy to obtain a desired beam width at two frequencies.

[0007]

In the conventional antenna device as described above, there are few design parameters for determining the electric performance, and it is difficult to design the antenna beam width to a desired value at two frequencies. There was a point.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to obtain an antenna device that can obtain a desired beam width at two frequencies.

[0009]

An antenna apparatus according to the present invention comprises a first linear primary radiator operating at a first frequency and a second linear primary radiator operating at a second frequency. And a flat reflector made of a metal plate bent into two, a first V-shaped reflector that reflects the radio wave of the first frequency, and a frequency selective reflector bent into two. And a second V-shaped reflector that has a smaller opening angle than the first V-shaped reflector and transmits the first frequency radio wave and reflects the second frequency radio wave. Wherein the first and second V-shaped reflectors each have a V-shaped corner that matches a predetermined straight line, and include the straight lines of two flat plates that constitute each V-shaped reflector. The planes of symmetry coincide and the first and second linear primary radiators are parallel to the straight line,
Further, they are arranged on the symmetry plane.

An antenna device according to the present invention comprises a first linear primary radiator operating at a first frequency, a second linear primary radiator operating at a second frequency, and a metal plate. And a V-shaped reflector for reflecting radio waves of the first and second frequencies;
And a frequency-selective reflector for transmitting radio waves of the second frequency and reflecting the radio waves of the second frequency, wherein the V-shaped reflector has a V-shaped corner coinciding with a predetermined straight line, and a V-shaped reflector. The frequency-selective reflector has a first symmetry plane including the straight line of the two flat plates constituting the plate, and the two edges of the frequency-selective reflector correspond to the straight line and constitute the V-shaped reflector. Has a second plane of symmetry including one of the plane plates and the straight line, and the first linear primary radiator is parallel to the straight line and on the first plane of symmetry. The second linear primary radiator is arranged in parallel with the straight line and on the second plane of symmetry.

Further, in the antenna device according to the present invention, the frequency selective reflection plate is constituted by a periodic metal foil pattern provided on a dielectric substrate.

Further, in the antenna device according to the present invention, the frequency selective reflection plate is constituted by a periodic hole formed in a metal foil provided on a metal or a dielectric plate.

Further, in the antenna device according to the present invention, the V-shaped reflector is formed of a conductive mesh.

Further, in the antenna device according to the present invention, the V-shaped reflector is constituted by a metal grid.

[0015] Further, the antenna device according to the present invention includes:
A plurality of antenna devices according to claim 1 are arranged along the straight line as element antennas, and a phase shifter is connected to the first and second linear primary radiators of each element antenna.

Further, the antenna device according to the present invention is characterized in that:
A plurality of antenna devices according to claim 2 are arranged along the straight line as element antennas, and a phase shifter is connected to the first and second linear primary radiators of each element antenna.

Further, the antenna device according to the present invention includes:
A plurality of antenna devices according to claim 7 are arranged as element antennas by rotating a plurality of them around a second axis parallel to the straight line.

Further, the antenna device according to the present invention includes:
A plurality of antenna devices according to claim 8 are arranged as element antennas by rotating a plurality of them around a second axis parallel to the straight line.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An antenna device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of the antenna device according to Embodiment 1 of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, reference numeral 1 denotes a first V-shaped reflector, and planar reflectors 11 and 12 which are metal plates are formed by straight lines L.
(4) It intersects. Reference numeral 2 denotes a second V-shaped reflector, which connects the frequency selective reflectors 21 and 22 to a straight line L (4).
Is composed by crossing.

The first and second V-shaped reflectors 1 and 2
Have a common symmetry plane 3 that includes a straight line L and has different opening angles formed by the respective flat plates.

Two frequency bands (f1, f2, f1 <f
In 2), reference numeral 51 denotes a first linear primary radiator operating at the frequency f1, and reference numeral 52 denotes a half-wave dipole antenna which is a second linear primary radiator operating at the frequency f2.

The first and second linear primary radiators 5
Reference numerals 1 and 52 are arranged on the symmetry plane 3. Here, the frequency selective reflectors 21 and 22 transmit at the frequency f1 and reflect at the frequency f2, and are formed of a periodic metal foil pattern provided on a dielectric substrate.

Next, the operation of the antenna device according to the first embodiment will be described with reference to the drawings.

The transmission will be described as an example. The radio waves of the frequency f1 radiated by the first linear primary radiator 51 with the vertical polarization parallel to the straight line L are transmitted to the frequency selective reflectors 21 and 22.
And reflected by the plane reflectors 11 and 12 to form a straight line L
And is radiated to a space in a direction 61 including the symmetry plane 3.
A part of this reflected wave is returned to the frequency-selective reflectors 21 and 22 again.
And is radiated to the space in the direction 61.

On the other hand, the radio wave of the frequency f2 radiated by the second linear primary radiator 52 with the vertical polarization parallel to the straight line L is reflected by the frequency selective reflection plates 21 and 22, and In the direction 62 which is the same direction as the direction 61. That is, the radio waves of the frequency f1 and the frequency f2 are reflected by the V-shaped reflectors 1 and 2 having different opening angles, respectively, and are radiated into space.

Here, design parameters for determining a radiation pattern of a V-shaped reflector (corner reflector) antenna will be described with reference to FIG.

The radio wave radiated by the primary radiator 5 is V
Is reflected by the V-shaped reflector 1 and is orthogonal to the V-shaped corner.
A radiation beam having a peak in the direction 6 including the symmetry plane 3 of the shaped reflector 1 is emitted. However, depending on design parameters,
In some cases, a peak of the radiation pattern is not formed in the direction 6 described above.

The V-shaped corner is determined by the width W, the height H, the opening angle α, and the distance S from the V-shaped corner of the primary radiator 5 of the two plane reflectors 11 and 12 constituting the V-shaped reflector 1. The shape of the radiation pattern in a plane (horizontal plane) perpendicular to the corresponding straight line is controlled. The radiation pattern shape in the plane including the V-shaped corner (vertical plane) matches the radiation pattern shape of the primary radiator 5 in this plane.

In the example shown in FIG. 1, the first V-shaped reflector 1
And the second V-shaped reflector 2, the width, the opening angle, and the distance from the V-shaped corner of the primary radiator of the plane reflector constituting each V-shaped reflector can be independently selected. It becomes easy to design the beam width in the horizontal plane of the antenna to a desired value.

By appropriately selecting the width and the opening angle of the plane reflectors constituting the two V-shaped reflectors 1 and 2, the first and second linear primary radiators 51 and 52 can be formed. The distance from the V-shaped corner can be equalized. In this case, the primary radiator can be simplified by configuring the first and second linear primary radiators 51 and 52 as one linear primary radiator shared by two frequency bands.

Further, the two frequency bands f1 and f2 are defined as f1
> F2, and the same applies to the case where the frequency selective reflecting mirrors 21 and 22 are constituted by periodic holes provided on a metal or a metal foil provided on a dielectric plate.

Although the case where the first V-shaped reflecting plate 1 is a metal plate has been described, the same applies when the first V-shaped reflecting plate 1 is formed of a conductive mesh.

The same applies to the case where the first V-shaped reflector 1 is constituted by a metal grid parallel to the straight line L.

Embodiment 2 Embodiment 2 An antenna device according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 3 is a diagram showing a configuration of the antenna device according to Embodiment 2 of the present invention.

In FIG. 3, reference numeral 1 denotes a V-shaped reflector, which is formed by intersecting plane reflectors 11 and 12, which are metal plates, with a straight line L (4). 21 is a frequency selective reflector,
One side thereof intersects with the straight line L (4).

The V-shaped reflector 1 has a first plane of symmetry 31 including a straight line L. A second V-shaped reflector is constituted by the frequency selective reflector 21 and the plane reflector 11, and a straight line L
And a second plane of symmetry 32 including:

Two frequency bands (f1, f2, f1 <f
In 2), reference numeral 51 denotes a first linear primary radiator operating at the frequency f1, and reference numeral 52 denotes a half-wave dipole antenna which is a second linear primary radiator operating at the frequency f2.
The first and second linear primary radiators 51 and 52 are arranged on the first symmetry plane 31 and the second symmetry plane 32, respectively. Here, the frequency selective reflection plate 21 transmits at the frequency f1 and reflects at the frequency f2, and is configured by a periodic metal foil pattern provided on the dielectric substrate.

Next, the operation of the antenna apparatus according to the second embodiment will be described with reference to the drawings.

The transmission will be described as an example. The radio wave of the frequency f1 emitted by the first linear primary radiator 51 with the vertical polarization parallel to the straight line L passes through the frequency selective reflector 21 and is reflected by the plane reflectors 11 and 12. Then, the light is radiated to a space in a direction 61 orthogonal to the straight line L and including the plane of symmetry 31. A part of this reflected wave is again
And is radiated to the space in the direction 61.

On the other hand, the radio wave of the frequency f2 radiated by the second linear primary radiator 52 with the vertical polarization parallel to the straight line L is reflected by the plane reflection plate 11 and the frequency selection reflection plate 21, and The light is radiated to a space in a direction 62 orthogonal to L and including the symmetry plane 32. That is, the radio waves of the frequency f1 and the frequency f2 are reflected by the V-shaped reflectors having different opening angles, respectively, and are radiated to spaces in different directions.

In the example shown in FIG. 3, the first V-shaped reflector and the second V-shaped reflector have an opening angle of a plane reflector constituting each V-shaped reflector, and a V of the primary radiator. Since the distance from the shape corner can be selected independently, it becomes easy to design the beam direction and beam width in the horizontal plane of the antenna to desired values at two frequencies.

The two frequency bands f1 and f2 are defined as f1
> F2, and the same applies to the case where the frequency selective reflecting mirror 21 is constituted by periodic holes provided on a metal or a metal foil provided on a dielectric plate.

Although the case where the first V-shaped reflecting plate is a metal plate has been described, the same applies when the first V-shaped reflecting plate is formed of a conductive mesh.

The same applies to the case where the first V-shaped reflector is constituted by a metal grid parallel to the straight line L.

Embodiment 3 Embodiment 3 An antenna device according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 4 is a diagram showing a configuration of an antenna device according to Embodiment 3 of the present invention.

In FIG. 4, reference numeral 71 denotes an element antenna constituted by the antenna device shown in the first embodiment, and 81 denotes a first linear primary radiator 51 for radiating radio waves of frequency f1.
Is a phase shifter connected to the second linear primary radiator 52 that emits a radio wave of the frequency f2.

If the excitation phase of each primary radiator is supplied in phase by the phase shifters 81 and 82, a sharp beam is radiated in the same direction in the horizontal plane for both the radio waves of the frequencies f1 and f2. Also, by feeding each primary radiator with an appropriate phase difference, the beam direction can be deflected in a vertical plane.

Embodiment 4 Embodiment 4 An antenna device according to Embodiment 4 of the present invention will be described with reference to the drawings. FIG. 5 is a diagram showing a configuration of an antenna device according to Embodiment 4 of the present invention.

In FIG. 5, reference numeral 72 denotes an element antenna constituted by the antenna device shown in the second embodiment, and 81 denotes a first linear primary radiator 51 for radiating radio waves of frequency f1.
Is a phase shifter connected to the second linear primary radiator 52 that emits a radio wave of the frequency f2.

If the excitation phase of each primary radiator is fed in phase by the phase shifters 81 and 82, the radio wave of the frequency f1 is in the vertical plane in the direction 61 shown in the second embodiment and the radio wave of the frequency f2. A sharp beam is emitted in the vertical plane in direction 62. Also, by feeding each primary radiator with an appropriate phase difference, the beam can be deflected in a vertical plane.

Embodiment 5 FIG. An antenna device according to a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a diagram showing a configuration of an antenna device according to Embodiment 5 of the present invention.

In FIG. 6, reference numeral 72 denotes an element antenna constituted by the antenna device shown in the second embodiment, and 73 denotes the frequency selective reflection plate 21 and the second linear primary device in the antenna device shown in the second embodiment. This is an element antenna constituted by an antenna device excluding the radiator 52.

In the same figure, reference numeral 81 denotes a phase shifter connected to a first linear primary radiator 51 for radiating a radio wave of a frequency f1, and 82 a second linear radiator for radiating a radio wave of a frequency f2. Is a phase shifter connected to the primary radiator 52.

If the excitation phase of each primary radiator is supplied in phase by the phase shifters 81 and 82, a sharp beam is emitted in the vertical plane. Here, in the element antenna 92 in which f1≪f2 in the two frequency bands f1 and f2, if the beam width in the vertical plane of the frequency f2 is sufficiently smaller than the beam width in the vertical plane of the frequency f1, the in-phase is obtained. In order to set the beam width in the vertical plane in the fed array state to a desired value, it is necessary to provide a primary radiator radiating the frequency f2 and a frequency selective reflector to all the element antennas as in the fifth embodiment. There is no.

As shown in FIG. 6, by using all six element antennas for the frequency band f1 and using three element antennas for the frequency band f2, it is possible to obtain a desired frequency band in a vertical plane. Can be obtained. Further, by feeding each primary radiator with an appropriate phase difference, the beam direction can be inclined in a vertical plane.

Embodiment 6 FIG. An antenna device according to Embodiment 6 of the present invention will be described with reference to the drawings. FIG. 7 is a diagram showing a configuration of an antenna device according to Embodiment 6 of the present invention.

In FIG. 7, reference numeral 91 designates the antenna device shown in the third embodiment as an element antenna. Further, a straight line L ′ which is 100 is
1 is parallel to a straight line L coinciding with the corner of the V-shaped reflector.

This antenna device has one element antenna 9
A plurality of element antennas are arranged at a position where 1 is rotated around a straight line L ′. By superposing beams in the horizontal plane of each frequency band of the adjacent element antennas 91 at an appropriate crossover level, an antenna device having a substantially non-directional radiation pattern in the horizontal plane can be obtained.

Embodiment 7 FIG. An antenna device according to Embodiment 7 of the present invention will be described with reference to the drawings. FIG. 8 is a diagram showing a configuration of an antenna device according to Embodiment 7 of the present invention.

In FIG. 8, reference numeral 92 designates the antenna device shown in the fourth embodiment as an element antenna. The same operation as in the sixth embodiment is performed.

The same operation is performed by using the element antenna 93 of the fifth embodiment.

[0063]

As described above, the antenna device according to the present invention has the first linear primary radiator operating at the first frequency and the second linear primary radiator operating at the second frequency. A radiator and a planar reflector made of a metal plate bent into two, and a first V that reflects radio waves of the first frequency
The first V-shaped reflector has a smaller opening angle than that of the first V-shaped reflector, and transmits the first frequency radio wave to the second V-shaped reflector. A second V-shaped reflector for reflecting radio waves having a frequency of
And the second V-shaped reflector has the respective V-shaped corners coincident with a predetermined straight line, and the two plane plates constituting each V-shaped reflector have the same symmetrical plane including the straight line. ,
Since the first and second linear primary radiators are arranged in parallel with the straight line and on the plane of symmetry, the beam width in the horizontal plane of the antenna at two frequencies is designed to a desired value. This has the effect of making it easier to perform.

As described above, the antenna device according to the present invention comprises a first linear primary radiator operating at a first frequency and a second linear primary radiator operating at a second frequency. And a flat reflector made of a metal plate which is bent into two to reflect the radio waves of the first and second frequencies.
A reflector for transmitting the radio wave of the first frequency and the second
And a frequency selection reflector that reflects radio waves of a frequency of
The V-shaped reflector has a first symmetry plane whose V-shaped corner coincides with a predetermined straight line, and includes the straight line of two flat plates constituting the V-shaped reflector, and The selective reflection plate has one edge coincident with the straight line, and has a second plane of symmetry including one of the two flat plates constituting the V-shaped reflection plate and the straight line; The linear primary radiator is disposed parallel to the straight line and on the first plane of symmetry, and the second linear primary radiator is parallel to the straight line and Since the antennas are arranged on the two symmetry planes, it is easy to design the beam direction and the beam width in the horizontal plane of the antenna to desired values at two frequencies.

Further, in the antenna device according to the present invention, as described above, the frequency selective reflection plate is constituted by the periodic metal foil pattern provided on the dielectric substrate, so that the antenna has two frequencies within the horizontal plane of the antenna. There is an effect that it becomes easy to design the beam width to a desired value.

Further, in the antenna device according to the present invention, as described above, since the frequency selective reflection plate is constituted by a periodic hole formed in a metal foil provided on a metal or a dielectric plate, two frequency This makes it easy to design the beam width of the antenna in the horizontal plane to a desired value.

Further, in the antenna device according to the present invention, as described above, since the V-shaped reflector is formed by the conductive mesh, the beam width in the horizontal plane of the antenna is designed to a desired value at two frequencies. This has the effect of making it easier.

Further, in the antenna device according to the present invention, as described above, since the V-shaped reflector is formed by the metal grating, the beam width in the horizontal plane of the antenna is designed to a desired value at two frequencies. This has the effect of making it easier.

Further, the antenna device according to the present invention
As described above, a plurality of the antenna devices according to claim 1 are arranged along the straight line as element antennas, and the phase shifters are connected to the first and second linear primary radiators of each element antenna. Therefore, it is easy to design various beams in the horizontal plane of the antenna at two frequencies.

Further, the antenna device according to the present invention
As described above, a plurality of the antenna devices according to claim 2 are arranged along the straight line as element antennas, and a phase shifter is connected to the first and second linear primary radiators of each element antenna. Therefore, it is easy to design various beams in the horizontal plane of the antenna at two frequencies.

Further, the antenna device according to the present invention
As described above, since the antenna device according to claim 7 is arranged as a plurality of element antennas by rotating around the second axis parallel to the straight line, various beams in the horizontal plane of the antenna are designed at two frequencies. This has the effect of making it easier to perform.

Further, the antenna device according to the present invention
As described above, since the antenna device according to claim 8 is arranged as a plurality of element antennas by rotating around the second axis parallel to the straight line, various beams in the horizontal plane of the antenna are designed at two frequencies. This has the effect of making it easier to perform.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an antenna device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining design parameters for determining a radiation pattern of a V-shaped reflector (corner reflector) antenna in the antenna device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of an antenna device according to Embodiment 2 of the present invention.

FIG. 4 is a diagram showing a configuration of an antenna device according to Embodiment 3 of the present invention.

FIG. 5 is a diagram showing a configuration of an antenna device according to Embodiment 4 of the present invention.

FIG. 6 is a diagram showing a configuration of an antenna device according to Embodiment 5 of the present invention.

FIG. 7 is a diagram showing a configuration of an antenna device according to Embodiment 6 of the present invention.

FIG. 8 is a diagram showing a configuration of an antenna device according to Embodiment 7 of the present invention.

FIG. 9 is a diagram showing a configuration of a conventional antenna device.

[Explanation of symbols]

1 V reflector, 11 plane reflector, 12 plane reflector, 2 V reflector, 21 frequency selective reflector, 22
Frequency selective reflector, 3 symmetry plane, 31 symmetry plane, 32
Plane of symmetry, 5 primary radiator, 51 primary radiator, 52 primary radiator, 71 element antenna, 72 element antenna, 7
3-element antenna, 81 phase shifter, 82 phase shifter, 91
Element antenna, 92 element antenna, 93 element antenna.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5J020 AA03 AA06 BA04 BA05 BA07 BC09 BD03 BD04 DA08 DA09 5J021 AA02 AB03 BA01 BA05 CA01 DA03

Claims (10)

[Claims] 1. A first linear primary radiator operating at a first frequency, a second linear primary radiator operating at a second frequency, and a planar reflector made of a metal plate. It is composed by bending into one
A first V-shaped reflector for reflecting the radio wave of the first frequency, and a frequency-selective reflector that is bent into two,
Opening angle of bending is smaller than that of the V-shaped reflector of
And a second V-shaped reflector that transmits radio waves of the frequency V and reflects the radio waves of the second frequency. The first and second V-shaped reflectors each have a predetermined V-shaped corner. The planes of symmetry including the straight line coincide with the straight line, and the two plane plates constituting the respective V-shaped reflectors coincide with each other. An antenna device which is arranged in parallel and on the symmetry plane. 2. A first linear primary radiator operating at a first frequency, a second linear primary radiator operating at a second frequency, and a planar reflector made of a metal plate. It is composed by bending into one
A V-shaped reflector that reflects the radio waves of the first and second frequencies; and a frequency selective reflector that transmits the radio waves of the first frequency and reflects the radio waves of the second frequency. The reflector has a first symmetry plane whose V-shaped corner coincides with a predetermined straight line and includes the straight line of the two flat plates constituting the V-shaped reflector. Has a second plane of symmetry having one edge coincident with the straight line and including the straight line and one of the two flat plates constituting the V-shaped reflector; the first linear shape Primary radiator is disposed parallel to the straight line and on the first plane of symmetry, and the second linear primary radiator is parallel to the straight line and the second symmetrical An antenna device which is arranged on a surface. 3. The antenna device according to claim 1, wherein the frequency selective reflection plate is formed by a periodic metal foil pattern provided on a dielectric substrate. 4. The antenna device according to claim 1, wherein the frequency selective reflection plate is formed of a periodic hole formed on a metal or a metal foil provided on a dielectric plate. 5. The antenna device according to claim 1, wherein the V-shaped reflector is made of a conductive mesh. 6. The antenna device according to claim 1, wherein the V-shaped reflector is formed of a metal grid. 7. A plurality of antenna devices according to claim 1 are arranged along said straight line as element antennas, and a phase shifter is connected to each of the first and second linear primary radiators of each element antenna. An antenna device comprising: 8. A plurality of the antenna devices according to claim 2 are arranged along the straight line as element antennas, and a phase shifter is connected to each of the first and second linear primary radiators of each element antenna. An antenna device comprising: 9. An antenna device according to claim 7, wherein a plurality of the antenna devices according to claim 7 are arranged as element antennas and rotated around a second axis parallel to the straight line. 10. An antenna device, wherein a plurality of the antenna devices according to claim 8 are arranged as element antennas by rotating about a second axis parallel to the straight line.