JP5520989B2 - Antenna and base station antenna - Google Patents

Description

  The present invention relates to an antenna and a base station antenna, and more particularly to an antenna capable of reducing a deviation of a 3 dB half-value angle of a magnetic field in-plane directivity.

A dipole antenna with a reflector whose polarization direction is perpendicular to the ground is known. FIG. 15 is a diagram showing a schematic configuration of a conventional dipole antenna with a reflector.
In the figure, reference numeral 1 denotes a reflector, and an array structure in which a plurality of vertically polarized dipole antenna elements (hereinafter referred to as antenna elements) (21, 22) are arranged on the reflector 1. Radiating elements are arranged. Here, the antenna elements (21, 22) may be formed on a dielectric substrate by a printed wiring technique, or a metal rod, a tube, or the like may be used.

  As prior art documents related to the invention of the present application, there are the following.

JP 2003-264426 A

FIG. 16 to FIG. 21 show the magnetic field plane (in the horizontal plane) directivity characteristics (directional characteristics in the XY plane in FIG. 15) of the dipole antenna with a reflector shown in FIG.
16 shows a frequency (f) of 1.437 GHz, FIG. 17 shows a frequency (f) of 1.496 GHz, FIG. 18 shows a frequency (f) of 1.7 GHz, FIG. 19 shows a frequency (f) of 1.8 GHz, FIG. Indicates the directivity characteristics when the frequency (f) is 1.93 GHz, and FIG. 21 shows the directivity characteristics when the frequency (f) is 2.12 GHz.
As can be seen from the graphs of FIGS. 16 to 21, the half-value angle when the frequency (f) is 1.437 GHz is 83.2 °, the half-value angle when the frequency (f) is 1.496 GHz is 81.7 °, The half-value angle when the frequency (f) is 1.7 GHz is 76.0 °, the half-value angle when the frequency (f) is 1.8 GHz is 73.9 °, and the half-value angle when the frequency (f) is 1.93 GHz. When the angle is 71.3 ° and the frequency (f) is 2.12 GHz, the half-value angle is 68.1 °. Here, the half-value angle is a beam width obtained from an angle at which the gain is reduced by 3 dB from the peak.
Thus, in the conventional dipole antenna with a reflector, the deviation of the half-value angle of the in-plane directivity characteristic is 68.1 ° to 83.2 °. For example, the design center frequency of the conventional dipole antenna with a reflector is When (fo) is 1.8 GHz, there is a problem that the deviation of the half-value angle of the directivity characteristic in the magnetic field in the frequency ratio band of 40% (1.427 GHz to 2.17 GHz) is as large as about 15 °. .
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide an antenna in which the deviation of the half-value angle of the in-plane magnetic field directivity is smaller than that of the conventional antenna, and the antenna. It is to provide a base station antenna to be used.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
(1) a planar reflector, the example Bei a radiating element disposed at a reflection plate by a predetermined distance, the reflector, in a direction parallel to the waves of the electric field radiated from the radiating element have a pair of slits in the ends of both ends, the pair of slits, along said direction parallel across the radio wave of the electric field radiated from the radiating element, is provided over the entire length of the two ends.
(2) a flat first reflecting plate, said Bei example a radiating element disposed first reflector and at a predetermined interval, is radiated from the radiating element of the first reflector have a pair of second reflection plate arranged at a predetermined interval in a direction parallel across the wave field, the pair of second reflectors, said first reflector and the same plane And provided along the both ends of the first reflecting plate in the direction parallel to the electric field of the radio wave radiated from the radiating element over the entire length of the both ends .
(3) A first reflector, and a radiating element disposed at a predetermined interval from the first reflector, and an electric field of radio waves radiated from the radiating element of the first reflector A pair of second reflecting plates disposed at predetermined intervals on both ends in a parallel direction, and the pair of second reflecting plates are radiated from the radiation element of the first reflecting plate; Along the both ends in the direction parallel to the electric field of the radio wave, the first reflecting plate and the pair of second reflecting plates are arranged in direct current at least at one point. It is connected to the.
(4) In any one of (1) to (3), the radiating element is a dipole antenna element.
(5) In any one of (1) to (3), the radiating element is a plurality of dipole antenna elements arranged in a direction parallel to a magnetic field plane of a radio wave radiated from the radiating element.
(6) In any one of (1) to (3), the radiating element has an array structure in which a plurality of dipole antenna elements are arranged in a direction orthogonal to a magnetic field plane of a radio wave radiated from the radiating element. It is a radiating element.
(7) A base station antenna including the antenna according to (6) and a dielectric, and a cover that houses the antenna according to (6).

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the antenna which made the deviation of the half value angle of magnetic field in-plane directivity characteristic smaller than before.

It is a figure which shows schematic structure of the dipole antenna with a reflecting plate of Example 1 of this invention. It is a figure which shows schematic structure in the case of using the dipole antenna with a reflector of Example 1 of this invention as a base station antenna. It is a graph which shows the directional characteristic in a magnetic field (directional characteristic in XY plane of FIG. 1) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the directional characteristic in a magnetic field (directional characteristic in XY plane of FIG. 1) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the directional characteristic in a magnetic field (directional characteristic in XY plane of FIG. 1) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the directional characteristic in a magnetic field (directional characteristic in XY plane of FIG. 1) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the directional characteristic in a magnetic field (directional characteristic in XY plane of FIG. 1) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the directional characteristic in a magnetic field (directional characteristic in XY plane of FIG. 1) of the dipole antenna with a reflecting plate shown in FIG. It is a figure which shows schematic structure of the dipole antenna with a reflecting plate of Example 2 of this invention. It is a graph which shows the magnetic field in-plane directional characteristic (directional characteristic in XY plane of FIG. 8) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directional characteristic (directional characteristic in XY plane of FIG. 8) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directional characteristic (directional characteristic in XY plane of FIG. 8) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directional characteristic (directional characteristic in XY plane of FIG. 8) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directional characteristic (directional characteristic in XY plane of FIG. 8) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directional characteristic (directional characteristic in XY plane of FIG. 8) of the dipole antenna with a reflecting plate shown in FIG. It is a figure which shows schematic structure of the conventional dipole antenna with a reflecting plate. It is a graph which shows the magnetic field in-plane directivity characteristic (directional characteristic in the XY plane of FIG. 15) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directivity characteristic (directional characteristic in the XY plane of FIG. 15) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directivity characteristic (directional characteristic in the XY plane of FIG. 15) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directivity characteristic (directional characteristic in the XY plane of FIG. 15) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directivity characteristic (directional characteristic in the XY plane of FIG. 15) of the dipole antenna with a reflecting plate shown in FIG. It is a graph which shows the magnetic field in-plane directivity characteristic (directional characteristic in the XY plane of FIG. 15) of the dipole antenna with a reflecting plate shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted. Also, the following examples are not intended to limit the interpretation of the scope of the claims of the present invention.
[Example 1]
FIG. 1A is a cross-sectional view of a main part illustrating a schematic configuration of a dipole antenna with a reflector according to a first embodiment of the present invention.
In FIG. 1A, reference numeral 1 denotes a reflecting plate, and an array structure in which a plurality of pairs of vertically polarized dipole antenna elements (hereinafter referred to as antenna elements) (21, 22) are arranged on the reflecting plate 1. Radiating elements are arranged. Here, as shown in FIG. 1, the antenna elements (21, 22) may be formed on the dielectric substrate 2 by a printed wiring technique, or a metal rod, a tube, or the like may be used.
In the present embodiment, the reflector 1 is formed with slits 12 at both ends in a direction parallel to the electric field of the main body 11.
Here, the distance between the antenna elements (21, 22) (a in FIG. 1A) is 0.35λo, and the distance between the antenna elements (21, 22) and the reflector 1 (c in FIG. 1A) is 0.2λo, The width of the reflector 1 (e in FIG. 1A) is 10.25λo, the width of the main body 11 of the reflector 1 (b in FIG. 1A) is 0.7λo, and the width of the slit 12 in the reflector 1 (d in FIG. 1A). Is 0.25λo. Note that λo is a free space wavelength of the design center frequency (fo) of the dipole antenna with a reflector according to the present embodiment.
In the present embodiment, the main body 11 of the reflector 1 mainly functions as a reflector at high frequencies in the radio wave radiated from the antenna, and the low frequency in the radio wave radiated from the antenna. At the frequency on the side, the entire reflecting plate composed of the main body 11 and the outer portion of the slit 12 functions as a reflecting plate.
Thereby, in the dipole antenna with a reflector according to the present embodiment, it is possible to reduce the deviation of the half-value angle of the directivity characteristics in the magnetic field plane as compared with the conventional dipole antenna with a reflector.
FIG. 1B is a diagram illustrating a schematic configuration when the dipole antenna with a reflector according to the present embodiment is used as a base station antenna. In FIG. 1B, reference numeral 10 denotes an antenna cover.

The magnetic field surface (in the horizontal plane) directivity (directivity in the XY plane in FIG. 1) of the dipole antenna with a reflector according to the present embodiment is shown in FIGS.
2 shows a frequency (f) of 1.437 GHz, FIG. 3 shows a frequency (f) of 1.496 GHz, FIG. 4 shows a frequency (f) of 1.7 GHz, FIG. 5 shows a frequency (f) of 1.8 GHz, FIG. Is the directivity characteristic when the frequency (f) is 1.93 GHz and FIG. 7 is the frequency characteristic when the frequency (f) is 2.12 GHz.
As can be seen from the graphs of FIGS. 2 to 7, the half-value angle when the frequency (f) is 1.437 GHz is 75.3 °, the half-value angle when the frequency (f) is 1.496 GHz is 74.6 °, The half-value angle when the frequency (f) is 1.7 GHz is 73.5 °, the half-value angle when the frequency (f) is 1.8 GHz is 74.0 °, and the half-value angle when the frequency (f) is 1.93 GHz. The half angle when the angle is 72.6 ° and the frequency (f) is 2.12 GHz is 75.6 °.
Thus, in the dipole antenna with a reflector according to the present embodiment, the deviation of the half-value angle of the in-plane directivity characteristic is 72.6 ° to 75.6 °. For example, the dipole antenna with a reflector according to the present embodiment. When the design center frequency (fo) is 1.8 GHz, the deviation of the half-value angle of the in-plane directional characteristics in the frequency ratio band of 40% (1.427 GHz to 2.17 GHz) should be reduced to about 3 °. Is possible. In particular, the half-value angles of the frequency (f) of 1.437 GHz and the frequency (f) of 2.12 GHz are almost the same as 75.3 ° and 75.6 °.
As described above, the dipole antenna with a reflector according to the present embodiment can reduce the deviation of the half-value angle of the in-plane directional characteristics of the magnetic field, compared with the conventional dipole antenna with a reflector.

[Example 2]
FIG. 8 is a cross-sectional view of an essential part showing a schematic configuration of a dipole antenna with a reflector according to Embodiment 2 of the present invention.
In FIG. 8, reference numeral 1 denotes a reflecting plate. On the reflecting plate 1, a radiating element having an array structure in which a plurality of pairs of vertically polarized antenna elements (21, 22) are arranged. Here, the antenna elements (21, 22) may be formed on the dielectric substrate 2 by a printed wiring technique as shown in FIG. 8, or a metal rod, a tube, or the like may be used.
In this embodiment, the reflecting plate 1 includes a first reflecting plate 13 and a pair of second reflecting plates 14 disposed on both sides in a direction parallel to the electric field of the first reflecting plate 13.
Here, the distance between the antenna elements (21, 22) (a in FIG. 8) is 0.35λo, and the distance between the antenna elements (21, 22) and the first reflector 13 (c in FIG. 8) is 0.2λo, the width of the first reflector 13 (b in FIG. 8) is 0.7λo, and the distance between the first reflector 13 and the second reflector 14 (d in FIG. 8) is 0.25λo. Is done. Note that λo is a free space wavelength of the design center frequency (fo) of the dipole antenna with a reflector according to the present embodiment.
In the present embodiment, the first reflector 13 mainly functions as a reflector at a higher frequency in the radio wave radiated from the antenna, and the lower frequency side in the radio wave radiated from the antenna. At this frequency, the entire reflector composed of the first reflector 13 and the pair of second reflectors 14 functions as a reflector.
Thereby, also in the dipole antenna with a reflecting plate of the present embodiment, it is possible to reduce the deviation of the half-value angle of the directivity characteristics in the magnetic field plane as compared with the conventional dipole antenna with a reflecting plate. In addition, the dipole antenna with a reflector of a present Example can also be used as a base station antenna as shown in FIG. 1B.

The magnetic field plane (in the horizontal plane) directivity (directivity in the XY plane of FIG. 1) of the dipole antenna with a reflector according to the present embodiment is shown in FIGS.
9 shows a frequency (f) of 1.437 GHz, FIG. 10 shows a frequency (f) of 1.496 GHz, FIG. 11 shows a frequency (f) of 1.7 GHz, FIG. 12 shows a frequency (f) of 1.8 GHz, FIG. Indicates the directivity characteristics when the frequency (f) is 1.93 GHz, and FIG. 14 shows the directivity characteristics when the frequency (f) is 2.12 GHz.
As can be seen from the graphs of FIGS. 2 to 7, the half-value angle when the frequency (f) is 1.437 GHz is 73.5 °, the half-value angle when the frequency (f) is 1.496 GHz is 73.6 °, The half-value angle when the frequency (f) is 1.7 GHz is 71.7 °, the half-value angle when the frequency (f) is 1.8 GHz is 71.8 °, and the half-value angle when the frequency (f) is 1.93 GHz. The half angle when the angle is 72.6 ° and the frequency (f) is 2.12 GHz is 73.4 °.
Thus, in the dipole antenna with a reflector according to the present embodiment, the deviation of the half-value angle of the in-plane directivity characteristic is 71.7 ° to 73.6 °. For example, the dipole antenna with a reflector according to the present embodiment. When the design center frequency (fo) is 1.8 GHz, the deviation of the half-value angle of the in-plane magnetic field directivity in the frequency ratio band 40% (1.427 GHz to 2.17 GHz) should be reduced to about 2 °. Is possible. In particular, the half-value angles of the frequency (f) of 1.437 GHz and the frequency (f) of 2.12 GHz are almost the same as 75.3 ° and 75.6 °.

In addition, the above-mentioned patent document 1 states that “a reflection having a dipole antenna, a reflector provided in parallel to the dipole antenna, and metal conductor columns arranged on the left and right sides of the reflector at a predetermined distance from the reflector. Dipole antenna with instrument "is described.
However, the above-mentioned Patent Document 1 aims at “adjusting the half-value width of the directivity in the horizontal plane”, and the above-mentioned Patent Document 1 includes “the half-value angle of the in-plane direction characteristic of the magnetic field” in the present invention. Is not disclosed.
In the above description, the case where a plurality of arrayed radiating elements in which a plurality of dipole antenna elements (21, 22) for vertical polarization are used is used as the radiating element is described. The radiating element is not limited to this, and various antenna elements such as one or a plurality of vertically polarized dipole antenna elements or vertically polarized patch antenna elements can be used.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

1 Reflector 2 Dielectric Substrate 10 Antenna Cover 11 Body
12 Slit 13 First Reflector 14 Second Reflector 21, 22 Dipole Antenna Element

Claims (7)

A flat reflector,
A radiating element disposed at a predetermined interval with the reflecting plate;
The reflector may have a pair of slits in the ends of the parallel direction of the both ends wave electric fields radiated from the radiating element,
The antenna is characterized in that the pair of slits are provided along both ends in a direction parallel to the electric field of the radio wave radiated from the radiating element over the entire length of the both ends . A flat first reflector;
A radiation element disposed at a predetermined interval from the first reflector;
Have a second reflector of the pair being disposed at a predetermined interval in a direction parallel across the field of the radio wave radiated from the radiating element of the first reflector,
The pair of second reflecting plates are disposed in the same plane as the first reflecting plate, and are disposed at both ends of the first reflecting plate in a direction parallel to the electric field of the radio wave radiated from the radiating element. Along the entire length of the both ends, an antenna. A first reflector;
A radiation element disposed at a predetermined interval from the first reflector;
A pair of second reflectors disposed at predetermined intervals on both ends of the first reflector in a direction parallel to the electric field of the radio wave radiated from the radiation element;
The pair of second reflecting plates are provided over both ends of the first reflecting plate in the direction parallel to the electric field of the radio wave radiated from the radiating element, over the entire length of the both ends . 1 of a reflector, the pair of second reflectors, at least one point, features and to luer antenna that are galvanically connected.   The antenna according to any one of claims 1 to 3, wherein the radiating element is a dipole antenna element.   4. The device according to claim 1, wherein the radiating element is a plurality of dipole antenna elements arranged in a direction parallel to a magnetic field surface of a radio wave radiated from the radiating element. 5. Antenna.   The radiating element is a radiating element having an array structure in which a plurality of dipole antenna elements are arranged in a direction orthogonal to a magnetic field plane of a radio wave radiated from the radiating element. 4. The antenna according to any one of items 3. An antenna according to claim 6;
A base station antenna comprising a cover configured of a dielectric and accommodating the antenna according to claim 6.

Images