JP4070784B2 - Antenna and array antenna - Google Patents

Description

  The present invention relates to an antenna and an array antenna, and more particularly to a 90 ° beam antenna.

FIG. 7 is a schematic diagram showing a schematic configuration of a conventional one-end short-circuited microstrip antenna.
In the figure, reference numeral 2 denotes a dielectric substrate, and a microstrip antenna element 3 is formed on the dielectric substrate 2. The microstrip antenna element 3 constitutes an excitation element.
In addition, a rectangular first radiating element 4 ₁ and second radiating element 4 ₂ are formed on the microstrip antenna element 3.
First radiating element 4 ₁ and the second radiating element 4 _2, with one side facing each other, the far side from the other end the one side ground potential is applied.
That is, when the antenna shown in FIG. 7 is a horizontally polarized wave and forms a 90 ° beam antenna (or an antenna having 90 ° horizontal plane directivity), two short-circuited patch antenna elements are used as the elements. They are arranged face to face.

However, in the antenna shown in FIG. 7 described above, in order to apply the first radiating element 4 ₁ and a second other end to the ground potential of the radiating element 4 _2, the first radiating element 4 ₁ and second the other end of the radiating element 4 _2, there needs to be soldered to a ground electrode formed on the back surface of the dielectric substrate 2 (a surface opposite to the surface where the microstrip antenna element 3 is formed).
For this reason, the antenna shown in FIG. 7 has a problem that not only the assembly is complicated, but also the variation in characteristics increases.
The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a 90 ° beam antenna and an array antenna that can be easily assembled by eliminating the step of soldering to a ground electrode. It is to provide.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
In order to solve the above-described problems, an antenna according to the present invention is disposed on the excitation element on the reflection surface of the reflection plate, the reflection surface of the reflection plate, and the reflection surface of the reflection plate. A first radiating element and a second radiating element having a rectangular shape , wherein the first radiating element and the second radiating element are not in contact with the reflector and the excitation element, and The end of the radiating element that does not face the second radiating element is bent toward the reflector, and the second radiating element is the end that does not face the first radiating element. Is bent toward the reflecting plate side .
In the present invention, the wavelength of the center frequency of the antenna used is λo, the side of the first radiating element that faces the second radiating element, and the second radiating element that faces the first radiating element. The distance between the first radiating element and the side facing the second radiating element, the length of the side perpendicular to the side facing the second radiating element, and the side of the second radiating element facing the first radiating element. Are the lengths of the sides orthogonal to each other, and L is the distance between the first radiating element and the second radiating element and the excitation element, respectively, 0.01λo ≦ T ≦ 0.06λo, 0.15λo ≦ L ≦ 0.30λo and 0.02λo ≦ H ≦ 0.15λo are satisfied.
In the present invention, the excitation element is an annular slot antenna element or a microstrip antenna element.
The present invention is also an array antenna in which the antennas described above are arranged in an array.

In the present invention, the first radiating element and the second radiating element are excited by an excitation element (annular slot antenna element or microstrip antenna element), so that the virtual center line ( the first radiating element in the first radiating element) is excited . An end facing the two radiating elements on the opposite side across an imaginary line passing through the center between the end facing the radiating element and the end of the second radiating element facing the first radiating element ; Electric fields are generated at both ends of the first radiating element and the second radiating element, and these electric fields serve as wave sources to radiate horizontally polarized radio waves.
Here, by combining the first radiating element, the second radiating element, and the reflecting plate, a 90 ° beam antenna can be configured with horizontally polarized waves.
Furthermore, by forming a plurality of excitation elements (annular slot antenna elements or microstrip antenna elements) and a distribution circuit for supplying power to them on a single dielectric substrate, an array antenna can be formed with a simple structure. Can be configured.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the present invention, it is possible to provide a 90 ° beam antenna and an array antenna that can be easily assembled by eliminating the step of soldering to the ground electrode.

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.
[Example 1]
FIG. 1 is a schematic perspective view showing an antenna according to Embodiment 1 of the present invention.
In the figure, 1 _1, 1 ₂ reflector 2 is a dielectric substrate, the dielectric substrate 2 is disposed at a predetermined interval in the reflecting plate 1 _second reflecting surface. An annular slot antenna element 5 is formed on the dielectric substrate 2. The annular slot antenna element 5 constitutes an excitation element.
Further, on the reflection surface of the reflector 1 _2, on the annular slot antenna element 5, a first radiating element ₆₁ of rectangular _shape, and the second and radiating element 6 ₂ are formed.
In this embodiment, the first radiating element ₆₁ and the second radiating element 6 _2, similar to a general parasitic elements are arranged without contacting the portion of the other conductive.
Here, the first radiating element ₆₁ and second radiation element 6 _2, for example, a dielectric substrate 2, is filled properly between the first radiating element ₆₁ and second radiation element 6 ₂ It is arranged on the annular slot antenna element 5 at a predetermined interval (H in FIG. 2) via a spacer made of a solid dielectric or an appropriate material.

Figure 2 is a diagram for explaining a first radiating element ₆₁ and the second radiation element 6 ₂ shown in FIG.
As shown in the figure, the first radiating element ₆₁ and the second radiating element 6 ₂ are disposed symmetric with respect to the imaginary center line 10. The first radiating element ₆₁ second radiation element 6 _2, the end farther from the imaginary center line 10, towards the reflector side Orimageraru.
In the present embodiment, when λo the wavelength of the used central frequency of the antenna, the distance between the ends facing each other across the first radiating element ₆₁ and the virtual center line 10 of the second radiation element 6 ₂ is T, The value of T is set to 0.01λo ≦ T ≦ 0.06λo.
Incidentally, in the antenna shown in FIG. 7, the distance between the ends facing each other across the first radiating element 4 ₁ and the second radiating element 4 ₂ imaginary center line 10 of approximately, are 0.13Ramudao.
Thus, in this embodiment, the interval of ends facing each other across the first radiating element ₆₁ and the second imaginary center line 10 of the radiating element 6 ₂ (T) is, than the antenna shown in FIG. 7 Small value.
Further, the length in the direction orthogonal to the first radiating element ₆₁ and the second imaginary center line 10 of the radiating element _{6 2} L1 (La + Lc in FIG. 2), the first radiating element ₆₁ and second radiation element 6 of a _second direction along the imaginary center line 10 of the length L2 (Lb in FIG. 2), the distance between the first radiating element ₆₁ and second radiation element 6 ₂ and the annular slot antenna element 5 H , L1, L2, and H are values that satisfy the following expression (1).
0.15λo ≦ L1 ≦ 0.30λo
0.10λo ≦ L2 ≦ 0.30λo
0.02λo ≦ H ≦ 0.15λo (1)

As described above, in the present embodiment, the distance between the ends facing each other across the first radiating element ₆₁ and the second imaginary center line 10 of the radiating element 6 ₂ (T) is the antenna shown in FIG. 7 Is also a small value.
Thus, in this embodiment, the excitation element (annular slot antenna element 5 is formed on the dielectric substrate 2), by exciting the first radiating element ₆₁ and the second radiating element 6 _2, an end portion opposite to each other with respect to the imaginary center line, the first radiating element ₆₁ an electric field is generated in the second end portions of the radiating element 6 _2, electric wave of the horizontal polarization of these electric fields become wave source is radiated The
Then, the first radiating element ₆₁ and second radiation element 6 _2, by combining a reflection plate (1 _{1, 1 2),} with horizontal polarization, it is possible to configure the beam antenna 90 ° .
FIG. 3 is a graph showing an example of directivity characteristics in the horizontal plane (XZ plane in FIG. 1) of the antenna of the present embodiment.
As shown in FIG. 3, it can be seen that the beam width of the antenna of this example is 90 °. The beam width is an angle in a range where the relative gain is −3 dB or less.
FIG. 4 is a graph showing an example of the VSWR characteristics of the antenna of this embodiment.
In the figure, the horizontal axis is frequency, the center frequency is 2.0 GHz, and the scale interval is 0.06 GHz.

[Example 2]
FIG. 5 is a schematic perspective view showing an antenna according to the second embodiment of the present invention.
This embodiment, in that using a second plate-shaped first radiating element ₆₁ and the second radiation element 6 _2, differs from the antenna of the above-described first embodiment.
That is, in this embodiment, the first radiating element ₆₁ and the second radiation element 6 ₂ which, end farther from the imaginary center line 10, as in Example 1 described above, the reflection plate side It is formed in a flat plate shape without being bent toward it.
In the present embodiment, the beam width in the horizontal plane is narrower than in the first embodiment.

[Example 3]
FIG. 6 is a schematic perspective view showing the array antenna according to the third embodiment of the present invention.
As shown in the figure, the array antenna of the present embodiment is configured by arranging four antennas of the above-described first embodiment in the Y direction of FIG. 1 to form an array antenna.
In this embodiment, since a plurality of excitation elements (annular slot antenna elements) and a distribution circuit for supplying power to them can be formed on the dielectric substrate 2, an array antenna can be configured with a simple structure. Can do.
In the above description, the case where the annular slot antenna element 5 formed on the dielectric substrate 2 is used as the excitation element has been described. However, the present invention is not limited to this, and the excitation element It is also possible to use the microstrip antenna element 3 shown in FIG.
The first radiating element 4 ₁ and the second radiating element 4 ₂ is also not limited to the rectangular shape but may be a elliptical shape.
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.

It is a model perspective view which shows the antenna of Example 1 of this invention. It is a figure for demonstrating the 1st radiating element and the 2nd radiating element which are shown in FIG. It is a graph which shows an example in the horizontal surface (XZ surface of FIG. 1) directivity of the antenna of Example 1 of this invention. It is a graph which shows an example of the VSWR characteristic of the antenna of Example 1 of this invention. It is a model perspective view which shows the antenna of Example 2 of this invention. It is a model perspective view which shows the array antenna of Example 3 of this invention. It is a schematic diagram which shows schematic structure of the antenna devised by this inventor before this invention.

Explanation of symbols

1, 1 ₁ , 1 ₂ Reflecting plate 2 Dielectric substrate 3 Microstrip antenna element 4 ₁ , 4 ₂ , 6 ₁ , 6 ₂ Radiating element 5 Annular slot antenna element 10 Virtual center line

Claims (4)

A reflector,
An excitation element disposed on a reflective surface of the reflector;
A rectangular first radiating element and a second radiating element disposed on the excitation element on the reflecting surface of the reflecting plate,
The first radiating element and the second radiating element are not in contact with the reflector and the excitation element,
The first radiating element has an end on the side not facing the second radiating element, bent toward the reflector side,
The antenna, wherein the second radiating element has an end on the side not facing the first radiating element bent toward the reflector . The wavelength of the use center frequency of the antenna is λo, and the distance between the side of the first radiating element facing the second radiating element and the side of the second radiating element facing the first radiating element is T, the length of a side of the first radiating element that is orthogonal to the side facing the second radiating element, and the length of a side of the second radiating element that is orthogonal to the side facing the first radiating element , L , respectively , and when the distance between the first radiating element and the second radiating element and the excitation element is H,
0.01λo ≦ T ≦ 0.06λo
0.15λo ≦ L ≦ 0.30λo
0.02λo ≦ H ≦ 0.15λo
The antenna according to claim 1 , wherein: The excitation element, the annular slot antenna element or antenna according to claim 1 or claim 2, characterized in that the microstrip antenna element. An array antenna comprising the antenna according to any one of claims 1 to 3 arranged in an array.

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