JPH05218728A - Antenna system - Google Patents

Abstract

PURPOSE:To keep a radiation characteristic close to a omnidirectivity in a plane of a conductor without need of a balun with simple structure by adopting the structure such that planer conductors are arranged opposite to each other, the planer directivity is uniformized and production of a cross polarized wave is suppressed. CONSTITUTION:A tri-plate line structure is adopted for the antenna system comprising a 1st conductor 7, a 2nd conductor 11, strip conductors 14a-14d, and dielectric bodies 9, 10. The conductors 14a-14d and slots 8a-8d, 13a-13d are coupled electromagnetically, an electric field is caused between slots and an electric field is caused in a horizontal plane of the conductor 7. The length of the conductors 14a-14d is equal to each other. Thus, the wave at each coupling point is in phase and an omnidirectional horizontal polarized wave is produced within the plane of the conductor 7. Since the conductors 7, 11 are of the same potential by the presence of the conductor 12, the production of the vertical polarized wave being the cross polarized wave is suppressed. The manufacture of the structure is easily realized on a board because the conductors 7, 11 and the conductors 14a-14d are easily manufactured on the board even when number of slots is increased to obtain the directivity close to the omnidirectional performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device in which horizontal polarization is omnidirectional in a horizontal plane.

[0002]

2. Description of the Related Art FIG. 12 shows an antenna disclosed on page 64 of "Handbook of Antenna Engineering" edited by The Institute of Electronics and Communication Engineers (published on October 30, 1980). In the figure, 1 and 2 are radiation conductors, 3 is a coaxial line, 4 is an inner conductor of the coaxial line 3 that feeds the radiation conductor 2, 5 is an outer conductor of the coaxial line 3, and the radiation conductor 1 on the side serving as a ground conductor Connected with. A balun 6 is provided to prevent a leakage current from being generated outside the outer conductor 5 of the coaxial line 3 and to balance-excite the antenna.

If the currents of the antennas shown in FIG. 12 are fed so that they flow in the same phase in the direction of going around the loop, it is possible to obtain a horizontally polarized wave having a uniform directivity in the plane including the antenna.

[0004]

Since the conventional antenna device is constructed as described above, a balun is required when feeding by a coaxial line, and the radiation conductors must be crossed. There was a problem that became complicated. If the number of radiating conductors is increased to make the directivity more uniform, the structure becomes complicated and the fabrication becomes difficult.

The present invention has been made in order to solve the above problems, and does not require a balun and has a simple structure and a radiation characteristic close to omnidirectional radiation. The purpose is to obtain the antenna device.

[0006]

According to another aspect of the present invention, there is provided an antenna device comprising: a first planar conductor; and a second planar conductor arranged to face the first planar conductor substantially in parallel. , Connecting means for bringing the first planar conductor and the second planar conductor to the same potential, and radially formed at corresponding positions of the first planar conductor and the second planar conductor, with one end Between the plurality of slots, which are open ends extending to the edge of the planar conductor, and between the first planar conductor and the second planar conductor, each planar conductor is insulated, Each of the strip conductors is excited by electromagnetic coupling, and a strip conductor is arranged so as to emit radio waves in phase from the open ends of the plurality of slots. Further, in the antenna device according to claim 2, the planar conductor, a plurality of slots radially formed on the planar conductor, one end of which is an open end extending to an edge of the planar conductor, and the planar conductor. And a strip conductor disposed so as to be insulated from each other, and each of the plurality of slots is excited by electromagnetic coupling so as to emit radio waves in the same phase from the open ends of the plurality of slots.

[0007]

According to the antenna device of the present invention, the first planar conductor, the second planar conductor arranged to face the first planar conductor substantially in parallel, and the first surface. Between the planar conductor and the second planar conductor, insulated from each planar conductor,
Each of the plurality of slots is excited by electromagnetic coupling to form a triplate line structure having good symmetry with a strip conductor arranged so as to radiate radio waves in phase from the open ends of the plurality of slots. Since the connection means for making the conductor and the second planar conductor have the same potential is provided, the in-plane directivity is made uniform and the generation of cross polarization is suppressed. 3. The antenna device according to claim 2, wherein the planar conductor, a plurality of slots radially formed on the planar conductor, one end of which is an open end extending to an edge portion of the planar conductor, are insulated from the planar conductor. Since each of the plurality of slots is excited by electromagnetic coupling and has a strip conductor arranged to emit radio waves in phase from the open ends of the plurality of slots, a microstrip line structure is provided. An antenna device having a uniform structure and a uniform in-plane directivity can be obtained.

[0008]

EXAMPLES Example 1. 1 is a perspective view of an antenna device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is an exploded view for explaining the configuration of the antenna device. In the figure, 7 is the first conductor on the upper surface, 8a
8d is a slot in which one end on each side of the first conductor 7 is extended to the conductor end to make it an open end and one end is short-circuited, 9 and 10 are dielectrics, 11 is a second conductor on the lower surface,
Reference numeral 12 is a first conductor 7 and a second conductor 11 in order to convert the coaxial line when feeding the coaxial line into a triplate line.
Are conductors that short-circuit the first conductor 7 and the second conductor 11, and 13a to 13d are conductor ends with one end on each side of the second conductor 11 on the lower surface. Slot that extends to the open end and has an open end and has one end short-circuited, 1
4a to 14d are strip conductors that feed the slots 8a to 8d and 13a to 13d, and 15 is a feeding point. Also,
FIG. 4 is a diagram showing the configuration when power is fed through the coaxial line, and is a cross-sectional view taken along the line BB in FIG. In FIG. 4, 16 is a coaxial line and 17 is an inner conductor. The first conductor 7 is provided on one surface of the dielectric 9, and the strip conductors 14a to 14 are provided on the other surface.
d is provided, the strip conductors 14a to 14d are provided on one surface of the dielectric 10, and the second conductor 11 is provided on the other surface of the dielectric 10 so that the first conductor 7 and the second conductor 11 are They have substantially the same shape and are arranged substantially in parallel. The slots 8a to 8d and 13a to 13d are provided so as to face each other.

Next, the operation will be described. This antenna device has a triplate line structure including a first conductor 7, a second conductor 11, strip conductors 14a to 14d, and dielectrics 9 and 10. Strip conductors 14a to 14d
The slots 8a to 8d and 13a to 13d are electromagnetically coupled to each other to generate an electric field between the slots and radiate the electric field in a horizontal plane in which the first conductor 7 is provided. Where strip conductor 1
The line lengths of 4a to 14d are equal. Than this,
It becomes in-phase at each coupling point, and omnidirectional horizontal polarization occurs in the plane in which the first conductor 7 is present. Further, since the conductor 12 makes the first conductor 7 and the second conductor 11 have the same electric potential, it is possible to suppress the generation of vertical polarization which is cross polarization.

Since the structure of this antenna device is as described above, the first conductor 7, the second conductor 11, the strip conductors 14a to 14d, etc. can be easily made by etching, for example, on the substrate, so that they are non-directional. It can be easily manufactured even if the number of slots 8a to 8d and 13a to 13d is increased in order to get closer to the characteristics.

Embodiment 2. FIG. 5 shows another embodiment of the antenna device of the present invention, which is the first conductor 7 of the first embodiment, and
It is an example of another shape of the second conductor 11. In the figures, the same symbols indicate the same things. The first conductor 7 on the upper surface and the second conductor 11 on the lower surface have the same shape. The shapes of the strip conductors 14a to 14d are the same as those in the first embodiment.

The operation is the same as that of the first embodiment, and the explanation is omitted.

Embodiment 3. FIG. 6 is another embodiment of the antenna device of the present invention, which is an embodiment in which the first conductor 7 and the second conductor 11 of Embodiment 1 are provided with taper. In the figures, the same symbols indicate the same things. The first conductor 7 on the upper surface and the second conductor 11 on the lower surface have the same shape. The shape of the strip line is the same as that of the first embodiment.

The operation is the same as that of the first embodiment, and the explanation is omitted.

Example 4. FIG. 7 shows another embodiment of the antenna device of the present invention, in which the conductor slot shape of the first embodiment is changed. In the figures, the same symbols indicate the same things. The first conductor 7 on the upper surface and the second conductor 11 on the lower surface have the same shape. By changing the shapes of the slots 8a to 8d and 13a to 13d, the slots 8a to 8d and 13a to 1 are changed.
Since the length of 3d can be made shorter than that of the above-described first to third embodiments, the size can be reduced.

Embodiment 5. FIG. 8 shows another embodiment of the antenna device of the present invention, in which the number of slots is changed. The first conductor 7 on the upper surface and the second conductor 11 on the lower surface have the same shape. FIG. 9 is a view showing the strip line of this embodiment, in which the slots 8a to 8c and the strip conductors 14a to 14c are electromagnetically coupled to each other. In the figures, the same symbols indicate the same things.

The operation is the same as that of the first embodiment, and the explanation is omitted.

Although the dielectrics 9 and 10 are used in the above embodiment, an air layer may be used.

Example 6. FIG. 10 is an exploded view showing the structure of still another embodiment of the antenna device of the present invention. Figure 1
FIG. 1 is a diagram showing a case where power is fed by a coaxial line as in FIG. In the drawings, the same symbols indicate the same things.

Next, the operation will be described. The strip conductors 14a to 14d and the slots 13a to 13d are electromagnetically coupled to each other to generate an electric field in the slots 13a to 13d and radiate the electric field in a horizontal plane. The line lengths of the strip conductors 14a to 14d are equal. As a result, in-plane horizontal polarized waves are generated in the plane in which the second conductor 11 is present, having the same phase at each coupling point.

Further, the shape of the second conductor 11 and the number and shape of the slots 13a to 13d can be the same as those shown in the above embodiments 2 to 5. Although the dielectric 10 is used in the above embodiment, it may be an air layer.

[0022]

As described above, according to the first aspect of the invention, it is possible to obtain an antenna device in which the cross-polarization is reduced and the in-plane directionality is uniform. Further, according to the invention of claim 2, there is an effect that it is possible to obtain an antenna device having a simple structure and a uniform in-plane directivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of the first embodiment of the present invention.

FIG. 3 is an exploded view showing the first embodiment of the present invention.

FIG. 4 is a sectional view taken along the line BB of the first embodiment of the present invention.

FIG. 5 is a plan view showing a second embodiment of the present invention.

FIG. 6 is a plan view showing a third embodiment of the present invention.

FIG. 7 is a plan view showing Embodiment 4 of the present invention.

FIG. 8 is a plan view showing a fifth embodiment of the present invention.

FIG. 9 is a plan view showing a strip conductor according to a fifth embodiment of the present invention.

FIG. 10 is an exploded view showing a sixth embodiment of the present invention.

FIG. 11 is a sectional view taken along the line AA of the sixth embodiment of the present invention.

FIG. 12 is a perspective view showing a conventional antenna device.

[Explanation of symbols]

 1 Radiation conductor 2 Radiation conductor 3 Coaxial line 4 Inner conductor 5 Outer conductor 6 Cylindrical conductor 7 First conductor 8a to 8d Slot line 9 Dielectric 10 Dielectric 11 Second dielectric 12 Conductor 13a to 13d Slot line 14a to 14d Strip conductor 15 Feed point 16 Coaxial line 17 Inner conductor

Claims (2)

[Claims] 1. A first planar conductor, and a second planar conductor arranged so as to face the first planar conductor substantially in parallel,
Connecting means for making the first planar conductor and the second planar conductor have the same potential, and radially formed at corresponding positions of the first planar conductor and the second planar conductor, one end of which is a surface. A plurality of slots that are open ends extending to the edge of the planar conductor, and are insulated from the respective planar conductors between the first planar conductor and the second planar conductor, and each of the plurality of slots And a strip conductor arranged to radiate radio waves in phase from the open ends of the plurality of slots. 2. A planar conductor, a plurality of slots radially formed on the planar conductor, one end of which is an open end extending to an edge portion of the planar conductor, and the plurality of slots being insulated from the planar conductor. ,
An antenna device, comprising: a strip conductor arranged to excite each of the plurality of slots by electromagnetic coupling and to radiate radio waves in phase from the open ends of the plurality of slots.