JP2002158531A - Element antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an element antenna, with which the occurrence of gain fluctuations on a high-frequency band is reduced, in the element antenna having wide band characteristics. SOLUTION: In the element antenna, with which the apexes of two plate-like conductors in the form of isosceles triangle are made to confront in the same plane and a feeding point is provided on the gap thereof, the angle characteristics of radiated power are reduced over a wide band by a band-like conductor connected, so as to be folded to the terminal part of the plate-like conductor orthogonal in the lengthwise direction of the element antenna and the total equilateral length becomes almost quarter of the wavelength of a first frequency and further, its own length becomes almost the quarter of the wavelength of a second frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element antenna having a wide band characteristic, in which the occurrence of gain fluctuation in angular characteristics in a high frequency band is reduced.

[0002]

2. Description of the Related Art FIG. 6A is a front view showing a conventional element antenna, FIG. 6B is a schematic diagram of a current distribution at a first frequency, and FIG. 6C is a schematic diagram of a current distribution at a second frequency. FIG. This is an example described in “Electromagnetic Wave Engineering”, pp. 90, edited by the Institute of Electronics, Information and Communication Engineers, 1983, Corona Corporation.
FIG. 7 is an angle characteristic diagram of the radiated power at the first frequency and the second frequency for explaining the operation principle.

In FIG. 7, reference numeral 23 denotes a plate conductor, 24 denotes an angle of the plate conductor 23, 25 denotes a symmetrical line of the plate conductor 23, 26 denotes a feeding point, 27 denotes a plate conductor, and 28 denotes a first conductor. The current distribution at the frequency, 29 is the current distribution at the second frequency.

Next, the operation will be described. For example, as described in the above-mentioned document “Electromagnetic wave engineering”, an antenna whose shape does not change at all even if the size of the antenna is arbitrarily enlarged or reduced is called a self-similar antenna, and its characteristics are constant regardless of frequency. . The conventional element antenna is shown in FIG.
As shown in (a), the front view is self-similar, and the plate-like conductor 23 constituting the element antenna has an infinite length, and the angle 24 for determining its shape is constant at any position. Thus, it is possible to obtain a characteristic that is constant regardless of the frequency.

[0005]

However, it is actually difficult to form a conventional element antenna with a plate-like conductor having an infinite size, and as shown in FIG. The length of the conductor 27 is １ ／ of the wavelength λ ₁ at the first frequency which is the lowest operating frequency, and the first
The current distribution 28 at the frequency of has a sine function shape which is substantially maximum at the feeding point 26 and minimum at the end of the plate-like conductor 27.

At the second frequency, which is approximately three times higher than the first frequency, as shown in FIG. 6C, the power supply point is formed on the plate-like conductor 27 as shown by a current distribution 29 at the second frequency. At 31, the shape of the sine function is drawn approximately toward the maximum and in the terminal direction, has a minimum value around 1/3 of the length in the middle, draws the shape of the sine function again, and becomes the minimum value again at the terminal.

As a result, the element antenna as a whole has three local maximum values on the plate-like conductor 32.
As shown in FIG. 7, the angle characteristic of the radiated power at the first frequency has one maximum value in the front direction on the plane including the symmetry line 25 of the plate-shaped conductor 27, and the radiated power at the second frequency has Since the angle characteristic has three maximum values, there is a problem that it is difficult to keep the angle characteristic constant in a wide operating frequency band.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to realize an element antenna which keeps the angle characteristic of radiated power within an operating frequency band substantially constant.

[0009]

According to a first aspect of the present invention, there is provided an element antenna having an isosceles triangular shape on the same plane, and apexes sandwiched between the two equal sides being opposed to each other with a minute gap therebetween.
Two plate-shaped conductors arranged on the same plane so as to be line-symmetric with respect to a symmetry line orthogonal to the gap, a feeding point provided in the minute gap, and each of the two plate-shaped conductors One end is connected to each of two vertices different from the above-mentioned vertex, and is extended so as to be equal in the above-mentioned equilateral direction, and further bent in parallel to a third side other than the above-mentioned equilateral side, and the total length of the above-mentioned equilateral sides is the first Is made of a band-shaped conductor whose length is about １ ／ wavelength of the second frequency and whose length is about １ ／ wavelength of the second frequency.

The element antenna according to a second aspect of the present invention has an isosceles triangular shape on the same plane, and apexes sandwiched between the two equal sides are opposed to each other with a minute gap therebetween, and are orthogonal to the gap. Two plate-like conductors arranged on the same plane so as to be line-symmetric with respect to the line of symmetry, a feeding point provided in the minute gap, and one end of each of the two plate-like conductors being the apex Each is connected to two different vertices and extended so as to be equal in the above-mentioned equilateral direction, and further bent in parallel to a third side other than the above-mentioned equilateral side, and the total length of the above-mentioned equilateral sides is approximately 1 of the first frequency.波長 wavelength, and its own length is approximately １ ／ of the second frequency.
It is made of a strip-shaped conductor that is extended so as to overlap without being in contact with each other so as to have a wavelength length.

The element antenna according to a third aspect of the invention has an isosceles triangular shape on the same plane, and the vertices sandwiched between the two equal sides are opposed to each other with a minute gap therebetween, and are orthogonal to the gap. Two plate-shaped conductors arranged on the same plane so as to be line-symmetric with respect to the first symmetry line, a feeding point provided in the minute gap, and one end of each of the two plate-shaped conductors A second vertex connected to each of the two vertices different from the vertex and extending so as to be equal in the equilateral direction; and a second orthogonal to the first symmetry line on the feed point in parallel with a third side other than the equilateral side. The line of symmetry is symmetrical, and is repeatedly bent in parallel to the third side other than the above-mentioned isosceles, so that the total length of the above-mentioned isosceles is approximately １ ／ wavelength of the first frequency, In addition, the length of itself is approximately 1/4 wavelength of the second frequency. It is made of so as to the strip conductor.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a front view showing an element antenna according to the first embodiment, and FIG.
Is a schematic diagram of a current distribution at a first frequency for explaining an operation principle, FIG. 3B is a schematic diagram of a current distribution at a second frequency, and FIG. 3 is a diagram of a first frequency and a second diagram for explaining characteristics. FIG. 6 is an angle characteristic diagram of radiated power at a frequency of FIG.

In the drawing, 1 is a plate-like conductor forming an isosceles triangle, 2 is an equilateral side of the plate-like conductor 1, 3 is a vertex sandwiched between the two equal-sides 2 of the plate-like conductor 1, and 4 is symmetrical. line,
Reference numeral 5 denotes a gap provided when the two plate-like conductors 1 are arranged so that the vertices 3 sandwiched between the two equal sides 2 are symmetrical with respect to the symmetry line 4, and 6 is provided on the gap 5. The feeding point 7 is a third side other than the equilateral 2, and 8 is connected to one end of each of the two plate-like conductors 1 at two vertices different from the vertex 3 and extends in the direction of the equilateral 2. Further, it is bent in parallel to the third side 7 other than the above-mentioned equal side 2, and the total length with the above-mentioned equal side 2 is set to about 1 of the first frequency.
帯 wavelength length, and the band-shaped conductor itself has a length of approximately １ ／ wavelength of the second frequency. 9 is a current distribution on the plate-shaped conductor 1 at the first frequency. , 1
0 is a current distribution on the strip conductor 8 at the first frequency, 11 is a current distribution on the plate conductor 1 at the second frequency, 12 is a current distribution on the strip conductor 8 at the second frequency, 13 Is the angular characteristic of the radiated power in the front direction at the first frequency, and 14 is the angular characteristic of the radiated power in the front direction at the second frequency.

Next, the operation of the element antenna will be described. In FIG. 2 (a), the first
Current distribution 9 at the frequency of
Together form a sine function such that the current distribution 10 at the first frequency has a maximum value at the feed point 6 and a minimum value at the upper end of the strip-shaped conductor 8. A first current distribution 9 at a first frequency on the plate-shaped conductor 1 and a first current distribution 10 at a first frequency on the strip-shaped conductor 8
Characteristic 13 of the radiated power in the front direction at the frequency of
In the front direction, the current distribution 10 at the first frequency on the strip-shaped conductor 8 appears to be opposite to the symmetry line 4 in the same direction, and the current distribution 10 cancels out.
Only the current distribution 9 at this frequency.

Next, the angle characteristic 14 of the radiated power in the front direction at the second frequency by the current distribution 11 at the second frequency on the plate-like conductor 1 and the current distribution 12 at the second frequency on the band-like conductor 8. In the front direction, the current distribution 12 at the second frequency on the strip-shaped conductor 8 appears in the same direction as the opposite direction with respect to the symmetry line 4, and cancels each other, so that the second frequency on the plate-shaped conductor 1 is canceled out. , The characteristic is only the current distribution 11.

Thus, the contribution to the radiated power is at the first frequency,
At the second frequency, only the current distributions 9 and 11 on the plate-like conductor 1 are provided, and as shown in FIG.
At any of the second frequencies, the angle characteristics in the front direction become small. That is, an effect is obtained that an element antenna that can reduce the influence of radiation pattern deformation at a frequency at which the total length of the two plate-shaped conductors 1 and the band-shaped conductors 8 becomes 3/2 wavelength can be realized.

Embodiment 2 FIG. FIG. 4 (a) is a front view of an element antenna device according to Embodiment 2 of the present invention, and FIG. 4 (b) is a perspective view. The schematic diagrams of the current distribution at the first frequency and the schematic diagrams of the current distribution at the second frequency according to the second embodiment are shown in FIGS.
The angular characteristics of the radiated power at the first frequency and the second frequency are the same as those in FIG.

In the figure, reference numeral 15 denotes a plate-shaped conductor, and 16 denotes an end of each of the two plate-shaped conductors 15 connected to two vertices different from the apex 3 and extended so as to be equal in the two equal sides. Further, it is bent in parallel to the third side 7 other than the above-mentioned equilateral 2 so that the total length with the above-mentioned equilateral 2 becomes approximately １ ／ wavelength of the first frequency. It is a strip-shaped conductor extended so as not to touch each other so as to have a length of about に な る wavelength of the frequency but to overlap.

As described above, according to the element antenna according to the second embodiment, the angle characteristics in the front direction are slightly different at both the first frequency and the second frequency based on the same principle as that of the first embodiment. Become. That is, an effect is obtained that an element antenna that can reduce the influence of radiation pattern deformation at a frequency at which the total length of the two plate-shaped conductors 1 and the band-shaped conductors 8 becomes 3/2 wavelength can be realized. further,
There is also obtained an effect that a small element antenna having a short length in the width direction of the antenna can be realized.

Embodiment 3 FIG. 5A is a front view showing an element antenna according to a third embodiment of the present invention, and FIG. 5B is a schematic diagram of a current distribution at a second frequency for explaining an operation principle. The schematic diagram of the current distribution at the first frequency in the third embodiment is shown in FIG.
(A) The angular characteristic diagram of the radiated power at the first frequency and the second frequency is the same as FIG.

In the figure, 17 is a plate-like conductor, 18 is a first line of symmetry for arranging the plate-like conductor 17 line-symmetrically on the same plane, and 19 is the first line of symmetry at the feeding point 6. The second symmetrical line 20 at a position orthogonal to the two plate-shaped conductors 17 has one end connected to each of two vertices different from the vertex 3 and extends so as to be equal in the two equal sides. Furthermore, the third other than the above-mentioned equilateral 2
The second symmetry line 19 orthogonal to the first symmetry line 18 is repeatedly bent in a line symmetry on the feeding point 6 in parallel with the side 7 of the above, so that the total length with the equal side 2 is the first frequency. Generally 1
A folded band-shaped conductor having a length of ４ wavelength and a length of itself being substantially １ ／ wavelength of the second frequency, 21 is a plate-shaped conductor at the second frequency A current distribution 17 and a current distribution 22 on the folded strip conductor 20 at the second frequency are shown.

As described above, according to the element antenna of the third embodiment, the angle characteristics in the front direction are slightly different at both the first frequency and the second frequency according to the same principle as that of the first embodiment. Become. That is, an effect is obtained that an element antenna that can reduce the influence of radiation pattern deformation at a frequency at which the total length of the two plate-shaped conductors 1 and the band-shaped conductors 8 becomes 3/2 wavelength can be realized. And
There is also obtained an effect that a small element antenna having a short length in the width direction of the antenna can be realized. Further, since the strip-shaped conductors 8 and 16 of the first and second embodiments are orthogonal to the longitudinal direction of the antenna, they generate cross polarization. Folded strip conductor 2
Since the components orthogonal to the longitudinal direction of the antenna are canceled out at the folded portion such as 0, there is also an effect that cross polarization can be performed.

[0023]

According to the first aspect of the present invention, an isosceles triangle is formed on the same plane, and vertices sandwiched between the two equal sides are opposed to each other with a predetermined gap therebetween, and are orthogonal to the gap. Two plate-shaped conductors arranged so as to be line-symmetric with respect to the line of symmetry, a feeding point provided in the gap, and one end of each of the two plate-shaped conductors is connected to two vertices different from the vertex. Connected and extended so as to be equal in the above-mentioned equilateral direction, and further bent in parallel to the third side other than the above-mentioned equilateral side, and the total length of the above-mentioned equilateral sides is approximately １ ／ wavelength of the first frequency. , And the length of the band-shaped conductor is made to be approximately １ ／ wavelength of the second frequency. Radiation pattern at a frequency where the sum of the wavelengths is 3/2 wavelength Effect that the antenna elements to improve the effect of shape can be realized.

According to the second aspect of the present invention, the shape is in the form of an isosceles triangle on the same plane, and the vertices sandwiched between the two equal sides are opposed to each other with a predetermined gap provided therebetween. Two plate-shaped conductors arranged on the same plane so as to be line-symmetric with respect to the line, a feeding point provided in the gap,
In each of the two plate-shaped conductors, one end is connected to each of two vertices different from the above-mentioned vertices to extend in the same-side direction so as to be equal, and further bent in parallel to a third side other than the above-mentioned same side, and Are in contact with each other so that their total length is approximately one-quarter wavelength of the first frequency and their length is approximately one-quarter wavelength of the second frequency. However, since it is composed of strip conductors extended so as to overlap with each other, the effect of radiation pattern deformation at a frequency at which the total length of the two plate conductors and the strip conductor is 3/2 wavelength is improved. Also, an effect that a small element antenna having a short length in the width direction of the antenna can be realized is obtained.

According to the third aspect of the present invention, the shape of an isosceles triangle is formed on the same plane, and the vertices sandwiched between the two equal sides are opposed to each other with a predetermined gap therebetween. Two plate-shaped conductors arranged on the same plane so as to be line-symmetric with respect to one symmetry line, a feeding point provided in the minute gap, and one end of each of the two plate-shaped conductors A second symmetry which is connected to two vertices different from the vertices and extends so as to be equal in the isosceles direction, and is orthogonal to the first symmetry line on the feed point in parallel with the third side other than the isosceles. The line is axisymmetrically repeatedly bent in parallel to the third side other than the above-mentioned isosceles, so that the total length with the above-mentioned isosceles is approximately １ ／ wavelength of the first frequency. Should be approximately ４ wavelength of the second frequency Due to the configuration at the strip conductor,
The total length of the two plate-shaped conductors and the band-shaped conductor is 3 /
The effect of improving the influence of the radiation pattern deformation at the frequency of two wavelengths, shortening the length of the antenna in the width direction, and realizing an element antenna that reduces the cross polarization component can be realized.

[Brief description of the drawings]

FIG. 1 is a first embodiment of an element antenna according to the present invention;
FIG.

FIGS. 2A and 2B are a schematic diagram of a current distribution at a first frequency and a schematic diagram of a current distribution at a second frequency for explaining an operation principle.

FIG. 3 shows a first frequency and a second frequency for explaining characteristics.
FIG. 6 is an angle characteristic diagram of radiated power at a frequency of FIG.

FIG. 4 is a second embodiment of the element antenna according to the present invention;
It is the front view and the perspective view which show.

FIG. 5 is a third embodiment of the element antenna according to the present invention;
FIG. 5 is a front view showing a current distribution and a schematic diagram of a current distribution at a second frequency for explaining the operation principle.

FIG. 6 is a front view showing a conventional element antenna, a schematic diagram of a current distribution at a first frequency, and a schematic diagram of a current distribution at a second frequency.

FIG. 7 is an angle characteristic diagram of radiated power at a first frequency and a second frequency for explaining an operation principle.

[Explanation of symbols]

Reference Signs List 1 plate conductor, 2 isosceles, 3 vertices, 4 symmetry lines, 5 gaps, 6 feeding point, 7 third side, 8 band conductor, 15 plate conductor, 16 band conductor, 17 plate conductor, 18 first Symmetry line, 19 Second symmetry line, 20 Folded bar conductor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference)

Claims (3)

[Claims] 1. A shape of an isosceles triangle on the same plane,
Two plate-like conductors arranged on the same plane so that vertices sandwiched between the two equal sides are opposed to each other with a predetermined gap provided therebetween and are symmetrical with respect to a line of symmetry orthogonal to the gap; And one end of each of the two plate-shaped conductors is connected to two vertexes different from the vertices, and extends so as to be equal in the equilateral direction,
Furthermore, it is bent in parallel to the third side other than the above-mentioned isosceles, so that the total length with the above-mentioned isosceles is approximately ４ wavelength of the first frequency, and the length of itself is the second length. An element antenna comprising a band-shaped conductor having a length substantially equal to a quarter wavelength of a frequency. 2. A shape of an isosceles triangle on the same plane,
Two plate-like conductors arranged on the same plane so that vertices sandwiched between the two equal sides are opposed to each other with a predetermined gap provided therebetween, and are symmetrical with respect to a line of symmetry orthogonal to the gap; And one end of each of the two plate-shaped conductors is connected to two vertices different from the vertices, and extends so as to be equal in the equilateral direction. 3 is bent in parallel to the side, and the total length with the above-mentioned equal side is approximately 1/1 of the first frequency.
4 wavelengths long, and the length of the second
An element antenna comprising a strip-shaped conductor extended so as to overlap with each other without being in contact with each other so as to have a length of about 波長 wavelength of the frequency of the element antenna. 3. A shape of an isosceles triangle on the same plane,
Two plate-like conductors arranged on the same plane so that vertices sandwiched between the two equal sides are opposed to each other with a predetermined gap provided therebetween and are line-symmetric with respect to a first symmetry line orthogonal to the gap. A power supply point provided in the minute gap, and one end of each of the two plate-shaped conductors different from the apex.
Connected to the two vertices and extended so as to be equal in the above-mentioned isosceles direction. Further, a second symmetry line orthogonal to the first symmetry line on the above-mentioned feeding point is drawn in parallel with the third side other than the above-mentioned isosceles. Symmetrically, the bending is repeated in parallel with the third side other than the above-mentioned equilateral side, so that the total length with the above-mentioned equilateral side becomes approximately 概 wavelength of the first frequency. Is an element antenna comprising a band-shaped conductor having a length substantially equal to a quarter wavelength of the second frequency.