JPH05226927A - Slot array antenna - Google Patents

Abstract

PURPOSE:To apply a radio wave to a flat plate waveguide through the use of a simple feeding mechanism and to differentiate a radiation direction of a beam of a circularly polarized wave from a direction of a normal of the conductor flat plate in the slot array antenna formed by making radiation slot elements to one conductor flat plate of the flat waveguide. CONSTITUTION:A simple feeding mechanism such as a coaxial waveguide converter 3 is provided at one end of a flat waveguide comprising upper and lower conductor flat lates 1a, 1b, a circularly polarized radio wave is generated by plural slot elements 5 comprising two slots arranged in a chevron shape and the arrangement interval of the slots is set so that the beam of the circularly polarized wave radiates to a required beam radiation direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slot array antenna used for communication, detection of the direction of arrival of radio waves, and the like.

[0002]

2. Description of the Related Art FIG. 17 shows, for example, "Characteristics of Radial Line Slot Antenna with Single Layer Structure" by Takahashi et al.
10 is a configuration diagram showing a conventional first slot array antenna shown in FIG. In the figure, 1a and 1b are circular upper and lower conductor flat plates arranged in parallel at a required interval, and 2 is the upper conductor flat plate 1a and the lower conductor flat plate 1b.
Dielectric plates 3 sandwiched between the two are lower conductor flat plates 1b
Of the coaxial waveguide converter, 4 is a coaxial line connected to the coaxial waveguide converter 3, and 5 is a plurality of slot elements spirally cut on the upper conductor flat plate 1a. As shown in FIG. 18, each slot element 5 is composed of two slots 6a and 6b that are inclined in an angle of 45 degrees with respect to the axis ρ and are arranged in a V shape. Reference numeral 7 denotes a termination conductor plate placed on the side surfaces of the upper and lower conductor plates 1a and 1b. A flat plate waveguide is constituted by the upper and lower conductive flat plates 1a and 1b.

Next, the operation will be described. The radio wave propagating through the coaxial line 4 enters the coaxial waveguide converter 3 and is converted into a cylindrical wave. Then, it propagates through the dielectric plate 2 between the conductor flat plates 1a and 1b in the diameter ρ direction, and becomes a circularly polarized radio wave by each slot element 5 and is radiated to the space above the upper conductor flat plate 1a. Here, regarding the arrangement interval of the slots 5 in the ρ direction, the direction of the radiation beam emitted from each slot element 5 into the space is the normal direction of the upper conductor flat plate 1a, that is, FIG.
Is set in the z-axis direction. Further, the arrangement interval Δρ between the orthogonal slots 6a and 6b forming the slot element 5 is such that the phase difference between the linearly polarized radio waves radiated into the space from the slots 6a and 6b is 90 degrees, and the circle in the z-axis direction is circular. It is set to be polarized wave. Therefore, a circularly polarized radiation beam is radiated from this slot array antenna in the normal direction of the upper conductor flat plate 1a.

FIG. 19 shows, for example, "Design of Beam-tilt Linearly Polarized Radial Line Slot Antenna" by Takada et al., Technical Report of IEICE [Antenna / Propagation] AP.
It is a block diagram which shows the 2nd conventional slot array antenna shown by 87-132, 1a, 1b, 3, 4, 5,
7 is the same as the above-mentioned conventional slot array antenna.
8 the upper and lower conductor flat 1a, 1b each d _u, spaced of d _l round conductor in the plate during, 9
Is an absorber disposed in the central portion of the gap between the conductor middle plate 8 and the upper conductor flat plate 1a, and 10 is a slow wave material placed on the conductor middle plate 8.

To explain the operation, the radio wave propagating through the coaxial line 4 is incident on the coaxial waveguide converter 3 and converted into a cylindrical wave, and the diameter ρ between the lower conductor flat plate 1b and the conductor middle plate 8 is converted. Propagate in the direction. This radio wave is reflected by the conductor plate 7 on the side surface, and the wave retarder 1 is passed between the upper conductor flat plate 1a and the conductor middle plate 8.
While the wavelength is shortened by 0, it propagates in the direction opposite to the diameter ρ, that is, in the center direction of the upper conductor flat plate 1a. Then, it is radiated from each slot element 5 to the space above the upper conductor flat plate 1a. Further, a part of the radio waves not radiated into the space by the slot element 5 is absorbed by the absorber 9. Here, the arrangement interval S of the slot elements 5 in the ρ direction and the φ direction
ρ and Sφ are set so that the direction of the radiation beam radiated into the space from each slot element 5 is a required direction inclined from the z axis. In addition, the array spacing Sρ and the slots 6a and 6b that are orthogonally arranged and constitute the slot element 5 are arranged.
The direction of arrangement is set such that the radio waves obtained by synthesizing the radio waves radiated into the space from the slots 6a and 6b are linearly polarized waves, and the polarization direction is a fixed beam emission direction. Therefore, a linearly polarized radiation beam is radiated from the slot array antenna in a desired beam radiation direction.

FIG. 20 is shown, for example, in Furukawa et al., "Beam-tilt type satellite broadcast receiving planar antenna using a single-layer waveguide", Technical Report of IEICE [Antenna / Propagation] A.P88-40. It is a block diagram which shows the conventional 3rd slot array antenna which was carried out. In the figure, 5 is a plurality of cross-shaped slot elements, 11 is a plurality of rectangular waveguides arranged so that their narrow surfaces are in contact with each other, and the slot elements 5 are cut into a plurality of wide surfaces. Is a branch waveguide connected to the end faces of a plurality of rectangular waveguides 11. FIG. 21 is a sectional view of the conventional third slot array antenna in the xz plane, and 13 is the rectangular waveguide 11 described above.
And a coupling hole placed between the branch waveguide 12.

In operation, the branch waveguide 12 will be described.
The radio wave propagating through the rectangular waveguide 1 passes through the coupling hole 13.
1, and propagates in the x direction. Then, it is radiated from the slot element 5 to the space above the rectangular waveguide 11. Here, the arrangement interval of the slot elements 5 in the x direction is set so that the direction of the radiation beam emitted from each slot element 5 into the space is a required angular direction tilted from the z axis in the xz plane. .. Further, since a cross-shaped slot is used as the slot element 5, the radio wave radiated into space from each slot element 5 is circularly polarized. Therefore, the circularly polarized radiation beam is radiated from the slot array antenna in the required beam radiation direction.

[0008]

The conventional slot array antennas are constructed as described above, but each has the following problems. The conventional first slot array antenna has a problem that a circularly polarized radiation beam can be radiated in the direction of the upper conductor flat plate 1a, that is, in the z-axis direction, but cannot be radiated in the direction tilted from the z-axis. there were. Further, the second conventional slot array antenna has a problem in that a linearly polarized radiation beam can be radiated in a direction tilted from the z-axis, but a circularly polarized radiation beam cannot be radiated. In addition, in the conventional third slot array antenna, a circularly polarized radiation beam can be radiated in a direction tilted from the z-axis, but a plurality of rectangular waveguides 11 must be arranged with their narrow surfaces in contact with each other. In addition, each square waveguide 1
There is a problem that the branch waveguide 12 and the coupling hole 13 must be provided to distribute the radio wave to the antenna 1, and the power feeding mechanism to the slot element 5 becomes complicated.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to supply power to the slot element by using a simple power supply mechanism, and at the same time, in a desired beam radiation direction tilted from the z-axis, The object is to obtain a slot array antenna capable of radiating a circularly polarized radiation beam.

[0010]

A slot array antenna according to a first aspect of the present invention is composed of two conductor flat plates arranged facing each other at a required interval, and between the two conductor flat plates. A flat plate waveguide in which a cylindrical wave or a plane wave propagates, a plurality of slot elements cut in the conductor flat plate of this flat plate waveguide, and a cylindrical wave or a plane wave is fed to the flat plate waveguide. And a power supply mechanism to
Further, as the slot element, two slots for radiating a linearly polarized radio wave are arranged in a shape of a, a c or a cross, and a pair of slots is used to generate a circularly polarized wave. At the same time, the array of the slot elements is adjusted so that the radiation direction of the radiation beam of the circularly polarized radio wave is different from the normal direction of the plate waveguide.

In the slot array antenna according to a second aspect of the present invention, the flat plate waveguide has a fan shape having an apex angle smaller than 180 degrees, and a cylindrical wave feeding mechanism is provided in the vicinity of the apex of the fan plate flat waveguide. Further, the radiation direction of the circularly polarized radiation beam is inclined from the normal direction of the fan-shaped flat plate waveguide to the apex direction of the fan-shaped flat plate waveguide.

According to a third aspect of the slot array antenna, a conductor plate is provided on the side surface including the apex of the fan-shaped flat plate waveguide.

According to a fourth aspect of the present invention, there are provided two slot array antennas so that the phase difference between the linearly polarized radio waves radiated from the two slots of the slot pair is 90 degrees in the required beam radiation direction. The slot spacing is set.

According to a fifth aspect of the slot array antenna, two linearly polarized radio waves radiated from the two slots of the slot pair are orthogonal to each other in a required beam emission direction. The slots are arranged.

In the slot array antenna according to a sixth aspect of the present invention, the linearly polarized radio waves radiated from the two slots of the slot pair are equal in amplitude to each other in the required beam emission direction. The size is set.

In a slot array antenna according to a seventh aspect of the present invention, the flat plate waveguide has a rectangular shape, a plane wave feeding mechanism is provided on one side of the rectangular flat plate waveguide, and a radiation direction of a circularly polarized radiation beam is provided. Is tilted from the normal direction of the rectangular flat plate waveguide to the feeding mechanism side of the rectangular flat plate waveguide.

[0017]

According to the first aspect of the present invention, it is composed of two conductor flat plates arranged to face each other with a required gap, and the cylindrical wave or the plane wave propagates between the two conductor flat plates. A slot array antenna is constituted by a flat plate waveguide, a plurality of slot elements cut into a conductive flat plate of the flat plate waveguide, and a feeding mechanism for feeding a cylindrical wave or a plane wave to the flat plate waveguide. This simplifies the method of supplying radio waves to the slot element. In addition, as a slot element, there are two slots that radiate linearly polarized radio waves.
Circularly polarized radio waves are generated by using a pair of slots arranged in the shape of a, a, C, or a cross, and by adjusting the array of slot elements, the circularly polarized wave is generated. The radiation direction of the radiation beam of the radio wave is different from the normal direction of the flat waveguide.

According to a second aspect of the present invention, the flat waveguide has a fan shape with an apex angle smaller than 180 degrees, and a cylindrical wave feeding mechanism is provided in the vicinity of the apex of the flat fan waveguide, whereby Radio waves are easily fed to the fan-shaped flat plate waveguide. Furthermore, by tilting the radiation direction of the circularly polarized radiation beam from the normal direction of the fan-shaped flat plate waveguide to the apex direction, the radiation of radio waves in unnecessary directions is suppressed.

According to a third aspect of the present invention, the conductor plate is provided on the side surface including the apex of the fan-shaped flat plate waveguide so that the electric waves of the cylindrical wave fed to the fan-shaped flat plate waveguide are provided on both side surfaces of the fan-shaped flat plate waveguide. From leaking to the outside. Further, the strength of the radio wave near the both side surfaces is reduced so that the radio wave can be efficiently fed to the slot element cut in the conductor flat plate.

In claim 4, the phase difference between the linearly polarized radio waves radiated from the two slots of the slot pair is:
By setting the arrangement interval of the two slots so as to be 90 degrees in the required beam emission direction, a circularly polarized beam having a small axial ratio in the required beam emission direction can be obtained.

According to a fifth aspect, the plane of polarization of the linearly polarized radio wave radiated from each of the two slots of the slot pair is:
By arranging the two slots so as to be orthogonal to each other in the required beam emission direction, a circularly polarized beam having a small axial ratio in the required beam emission direction can be obtained.

In the sixth aspect, the size of the two slots is set so that the amplitudes of the linearly polarized radio waves radiated from the two slots of the slot pair become equal in the required beam emission direction. As a result, a circularly polarized beam having a small axial ratio in the required beam emission direction can be obtained.

According to a seventh aspect of the present invention, the flat plate waveguide is formed in a rectangular shape, and a plane wave power feeding mechanism is provided on one side of the rectangular flat plate waveguide, whereby plane wave waves are easily fed to the rectangular flat plate waveguide. Become. Furthermore, by tilting the radiation direction of the circularly polarized radiation beam from the normal line direction of the rectangular flat plate waveguide to the side of the power feeding mechanism, radiation of radio waves in unnecessary directions is suppressed.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. FIG. 1 is a configuration diagram of a slot array antenna according to an embodiment of the present invention. In the figure, 1a and 1b are fan-shaped upper and lower conductor plates arranged in parallel with a required gap, and 3 is a coaxial waveguide converter arranged on the z axis near the apex of the fan-shaped lower conductor plate 1b. Reference numeral 4 denotes a coaxial line connected to the coaxial waveguide converter 3, and reference numeral 5 denotes a plurality of slot elements cut on the upper conductor flat plate 1a, which are flat conductors formed by the fan-shaped upper and lower conductor flat plates 1a and 1b. The wave tube is configured.

FIG. 2 also shows the slot element 5 shown in FIG.
6a and 6b are rectangles each having a length of about a half wavelength, which are arranged in a V shape on the u axis rotated by an angle φ from the x axis of FIG. It is a slot of. It is assumed that the slots 6a and 6b in FIG. 2 rotate in the direction of rotation from the u-axis when a radiation beam of right-handed circularly polarized radio waves is emitted from the slot array antenna of this embodiment.

Next, the operation will be described. The radio wave propagating through the coaxial line 4 enters the coaxial waveguide converter 3 and is converted into a cylindrical wave. Then, it propagates in the fan-shaped radial direction from the z-axis through the fan-shaped plate waveguide constituted by the upper and lower conductor plates 1a and 1b. Then, the radio waves are radiated to the space above the upper conductor flat plate 1a by each slot element 5.
Here, as shown in FIG. 3, the radiation direction of the radio wave radiated from the slot element 5 into the space is -x from the z axis in the xz plane.
The v-axis direction is inclined by an angle θ. That is, the direction is diagonally above the apex of the upper conductor flat plate 1a. In this case, the distance r and Δ from the coordinate origin O given by the following equation group
By arranging the slots 6a and 6b shown in FIG. 2 at the position r, the electric wave radiated into the space from each slot element 5 becomes v
It becomes a circularly polarized radiation beam that is directed in the axial direction.

[0027]

[Equation 1]

[0028]

[Equation 2]

[0029]

[Equation 3]

[0030]

[Equation 4]

However, λ ₀ is a free space wavelength and ε _r is a relative permittivity, which is 1 in this embodiment. Further, m is an integer of 1 or more. R shown in Formula (1) and Formula (2)
₁ indicates that the phase of the radio wave radiated into the space from each slot element 5 becomes co-phase in the v-axis direction, and the direction of the radiation beam is v.
It shows the condition in the axial direction. Further, r ₂ shown in the equations (1) and (3) gives a condition that the polarization direction of the circularly polarized radio wave radiated into space from each slot element 5 is constant in the v-axis direction. is there. The negative sign of the equation (3) shows the case of right-handed circular polarization, and the positive sign shows the case of left-handed circular polarization. Δr shown in the equation (4) is the slot 6
The phase difference between the linearly polarized radio waves radiated from a and 6b is 90 degrees in the v-axis direction, and the right-handed circularly polarized radio wave is radiated from the slot element 5 in the v-axis direction.

Example 2. In the first embodiment, the radiation direction of the beam is changed from the z axis to the −x direction within the xz plane by an angle θ.
Although the v-axis direction is inclined, the arrangement interval of the slot elements 5 in the x-axis direction is

[0033]

[Equation 5]

If it becomes less than or equal to R given by, the angle θ
Is negative, that is, when the radiation beam is directed in the + x direction from the z axis in the xz plane, radio waves are not emitted in an unnecessary direction, and the same effect as that of the first embodiment can be expected.

Example 3. Although the case where the radiation beam of the right-handed circularly polarized wave is radiated has been described in the first embodiment,
The same is true for left-handed circularly polarized waves.

Example 4. Further, in the first embodiment, the centers of the slots 6a and 6b are placed on the u-axis, but as shown in FIGS. 4 and 5, the slots 6a and 6b are arranged.
The same effect can be expected by displacing the center of each of the slots 6a and 6b by a distance d at a right angle to the u-axis within a range in which the slots 6a and 6b do not overlap each other, or by arranging them in an inverted A shape.

Example 5. In the first embodiment, the slots 6a and 6b do not overlap each other.
Similar effects can be expected even in the cross-arranged state in which some of them overlap as shown in FIG.

Example 6. Further, in the first embodiment, as the slots 6a and 6b, rectangular slots each having a length of about a half wavelength are used, but the length is not particularly limited to a half wavelength. Furthermore, the shape of the slot is not particularly limited as long as it is a slot that radiates a linearly polarized radio wave such as an oval shape or a shape in which a semicircle is connected to a short side of a rectangle.

Example 7. FIG. 7 shows that the relative permittivity ε _r is 1 between the upper conductor flat plate 1a and the lower conductor flat plate 1b of the first embodiment.
Since a larger dielectric plate 2 is sandwiched, the same effect as that of the first embodiment can be expected in this case as well.

Example 8. FIG. 8 is a side view showing an eighth embodiment of the present invention, in which the gap between the upper conductor flat plate 1a and the lower conductor flat plate 1b is large on the coaxial waveguide converter 3 side and small on the other side. It is a thing. Similar effects can be expected when the upper conductor flat plate 1a and the lower conductor flat plate 1b are not parallel to each other as in this embodiment.

Example 9. FIG. 9 is a constitutional view showing a ninth embodiment of the present invention, in which 14 is a conductor plate provided on both side surfaces including the apexes of the upper conductor flat plate 1a and the lower conductor flat plate 1b. The conductor plate 14 prevents radio waves of cylindrical waves propagating in the fan-shaped flat plate waveguide composed of the upper conductor flat plate 1a and the lower conductor flat plate 1b from leaking to the outside from both side surfaces of the fan-shaped flat plate waveguide. There is. Further, the strength of the radio wave near both side surfaces is reduced, and the slot element 5 cut in the upper conductor flat plate 1a is formed.
It is designed to efficiently supply radio waves to. In FIG. 9, the conductor plate 14 is provided on the entire side surface, but as shown in FIG. 10, the same effect can be expected if it is provided on a part of the side surface near the apex of the fan shape.

Example 10. FIG. 11 shows the tenth aspect of the present invention.
2 is a configuration diagram showing an embodiment of the present invention, in which a feeding rectangular waveguide 15 is used in place of the coaxial waveguide converter 3 as the cylindrical wave feeding mechanism of the first embodiment. In addition, FIG.
The cylindrical wave feeding mechanism of the ninth embodiment uses the feeding rectangular waveguide 15, and the slot elements 5 are arranged on the upper surface of a so-called H-plane fan-shaped horn antenna.
Similar effects can be expected in these cases.

Example 11. FIG. 13 is a configuration diagram of a slot element 5 of an embodiment according to claim 5 of the present invention.
Reference numerals a and 6b denote rectangular slots arranged in a V shape on the u axis rotated by an angle φ from the x axis and inclined from the u axis by an angle η. Angle η,

[0044]

[Equation 6]

With the angle given by, the polarization planes of the linearly polarized radio waves radiated from the slots 6a and 6b are orthogonal to each other in the v-axis direction of FIG. This gives v
A circularly polarized beam having a small axial ratio in the axial direction can be obtained.

Example 12 FIG. 14 is a configuration diagram of a slot element 5 of an embodiment according to claim 6 of the present invention.
a, 6b is on u axis and the rotation angle φ from the x-axis, are each an angle η only tilting of the shaped lengths are arranged in a shape l _a and l _b Ha with rectangular slots from the u axis. Each slot 6a, 6
The excitation amplitudes of b are E _a and E _b , respectively. Excitation amplitude E _a , E _b
The length of the slot l _a, can be controlled by adjusting the l _b, the ratio E _a / E _b of E _a and E _b,

[0047]

[Equation 7]

When the lengths l _a and l _b of the slots 6a and 6b are set so that the amplitudes of the linearly polarized radio waves radiated from the slots 6a and 6b in the v-axis direction of FIG. 3 become equal to each other. .. Therefore, a circularly polarized beam having a small axial ratio in the v-axis direction can be obtained.

Example 13. FIG. 15 is a configuration diagram of a slot array antenna of an embodiment according to claim 7 of the present invention. In the figure, 1a and 1b are rectangular upper and lower conductor plates arranged in parallel with a required gap, and 5 is a plurality of slot elements cut on the upper conductor plate 1a.
Reference numeral 15 is a rectangular waveguide, 16 is an H-plane fan-shaped horn in which the narrow tube wall of the rectangular waveguide 15 is expanded in a tapered shape, and the upper and lower conductor flat plates 1a and 1b are connected to the opening of the wide surface.
Reference numeral 17 is a dielectric plano-convex lens placed inside the H-plane fan-shaped horn 16.

FIG. 16 is a diagram showing the arrangement of the slot elements 5 shown in FIG. 15, and 6a and 6b are x in FIG.
On the x'-axis parallel to the axis, rectangular slots each having a length of about a half wavelength and arranged in a V shape inclined by 45 degrees from the x'-axis. In addition, x'of the slots 6a and 6b in FIG.
Regarding the rotation direction from the axis, it is considered that the radiation beam of the right-handed circularly polarized radio wave is emitted from the slot array antenna as in the first embodiment.

Next, the operation will be described. Rectangular waveguide 1
The radio wave propagating in 5 enters the H-plane fan horn 16 and becomes a cylindrical wave and propagates in the H-plane fan horn 16.
Then, the radio wave of the cylindrical wave is incident on the dielectric plano-convex lens 17, is converted into the radio wave of the plane wave by the dielectric plano-convex lens 17, and is incident on the flat waveguide formed by the upper and lower conductor flat plates 1a and 1b. To do. Then, the wave propagates in the flat waveguide in the x direction, and the radio waves are radiated to the space above the upper conductor flat plate 1a by each slot element 5. Here, the radiation direction of the radio wave radiated into the space from the slot element 5 is the v-axis direction inclined by the angle θ from the z-axis to the −x direction in the xz plane of FIG. The direction is diagonally above the apex of 1a. In this case, by arranging the slots 6a and 6b shown in FIG. 16 at the distances r and Δr from the y axis given by the following equation, the radio waves radiated into the space from each slot element 5 are directed in the v axis direction. It becomes a circularly polarized radiation beam.

[0052]

[Equation 8]

[0053]

[Equation 9]

However, λ ₀ is a free space wavelength and ε _r is a relative permittivity, which is 1 in this embodiment. Also, r ₀
Is a real number constant and m is an integer of 1 or more. As for r shown in Expression (8), the phase of the radio wave radiated into the space from each slot element 5 becomes a cophase in the v-axis direction, and the direction of the radiation beam is v.
It shows the condition in the axial direction. Further, in Δr shown in the equation (9), the phase difference between the linearly polarized radio waves radiated from the slots 6a and 6b is 90 degrees in the v-axis direction, and the right circularly polarized radio wave is emitted from the slot element 5. It represents the condition of emission in the v-axis direction.

[0055]

As described above, according to the present invention, it is composed of two conductor flat plates which face each other at a required interval, and a cylindrical wave or a plane wave is generated between the two conductor flat plates. A slot is formed by a flat plate waveguide adapted to propagate, a plurality of slot elements cut in the conductor flat plate of the flat plate waveguide, and a power feeding mechanism for feeding a cylindrical wave or a plane wave to the flat plate waveguide. An array antenna is constructed, and two slots for radiating linearly polarized radio waves are arranged as the slot element, and a pair of slots is arranged by arranging them in a shape of a, a shape of a c or a cross to form a circular polarization. Wave radio wave is generated and the array of the slot elements is adjusted so that the radiation direction of the circularly polarized radio wave radiation beam is different from the normal direction of the flat plate waveguide. Use the power supply mechanism to Together perform the feed to the element, the required beam radiation direction inclined from the z-axis, the effect of the slot array antenna is obtained which is capable of emitting a radiation beam of circularly polarized waves.

Further, the shape of the above-mentioned flat plate waveguide has an apex angle of 18
A fan shape smaller than 0 degree is provided, a cylindrical wave feeding mechanism is provided in the vicinity of the apex of the fan-shaped flat waveguide, and the radiation direction of the circularly polarized radiation beam is apex from the normal direction of the fan-shaped flat waveguide. By tilting in the direction, the electric wave of the cylindrical wave can be easily fed to the fan-shaped flat plate waveguide, and the emission of the electric wave in the unnecessary direction can be suppressed.

Further, by providing the conductor plate on the side surface including the apex of the fan-shaped flat plate waveguide, it is possible to prevent the electric wave of the cylindrical wave propagating through the fan-shaped flat plate waveguide from leaking to the outside from both side surfaces thereof. At the same time, there is an effect that the intensity of the radio wave near both side surfaces is reduced, and the radio wave is efficiently fed to the slot element cut in the conductor flat plate.

Further, the arrangement interval of the two slots is set so that the phase difference between the linearly polarized radio waves radiated from the two slots of the slot pair becomes 90 degrees in the required beam emission direction. As a result, there is an effect that a circularly polarized beam with a small axial ratio can be obtained in the required beam emission direction.

Similarly, by arranging the two slots so that the polarization planes of the linearly polarized radio waves radiated from the two slots of the slot pair are orthogonal to each other in the required beam emission direction, There is an effect that a circularly polarized beam having a small axial ratio in the beam emission direction can be obtained.

Similarly, by setting the size of the two slots so that the amplitudes of the linearly polarized radio waves radiated from the two slots of the slot pair are equal in the required beam emission direction, There is an effect that a circularly polarized beam having a small axial ratio can be obtained in a desired beam emission direction.

Further, the flat waveguide has a rectangular shape,
A plane wave feeding mechanism is provided on one side of this rectangular flat waveguide.
Furthermore, by tilting the radiation direction of the circularly polarized radiation beam from the normal direction of the rectangular flat plate waveguide to the feeding mechanism side, it becomes easier to feed the plane wave to the rectangular flat plate waveguide, and unnecessary This has the effect of suppressing the emission of radio waves in the direction.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a slot array antenna according to an embodiment of the present invention.

FIG. 2 is a diagram showing an array of slot elements according to an embodiment of the present invention.

FIG. 3 is a diagram showing a beam emission direction in one embodiment of the present invention.

FIG. 4 is a diagram showing an array of slot elements in the case of the inverted A array according to the embodiment of the present invention.

FIG. 5 is a diagram showing an array of slot elements in the case of the V-shaped array according to the embodiment of the present invention.

FIG. 6 is a diagram showing an array of slot elements in the case of a cross array according to an embodiment of the present invention.

FIG. 7 is a configuration diagram of a slot array antenna in which a dielectric plate is sandwiched between an upper conductor plate and a lower conductor plate according to an embodiment of the present invention.

FIG. 8 is a configuration diagram of a slot array antenna when the upper conductor flat plate and the lower conductor flat plate are not parallel to each other according to an embodiment of the present invention.

FIG. 9 is a configuration diagram of a slot array antenna in which conductor plates are provided on the entire side surfaces of an upper conductor plate and a lower conductor plate according to an embodiment of the present invention.

FIG. 10 is a configuration diagram of a slot array antenna in which a conductor plate is provided on a part of side surfaces of an upper conductor plate and a lower conductor plate according to an embodiment of the present invention.

FIG. 11 is a configuration diagram of a slot array antenna using a rectangular waveguide as a cylindrical wave feeding mechanism according to an embodiment of the present invention.

FIG. 12 is a configuration diagram of a slot array antenna using an H-plane fan horn antenna according to an embodiment of the present invention.

FIG. 13 is a diagram showing an array of slot elements when the rotation angle is η according to the embodiment of the present invention.

FIG. 14 is a diagram showing an arrangement of slot elements when the lengths of the slots are different according to the embodiment of the present invention.

FIG. 15 is a configuration diagram of a slot array antenna using a rectangular flat plate waveguide and a plane wave feeding mechanism according to an embodiment of the present invention.

FIG. 16 is a diagram showing an array of slot elements in the case of plane wave feeding according to an embodiment of the present invention.

FIG. 17 is a configuration diagram of a slot array antenna in a first conventional example.

FIG. 18 is a diagram showing an array of slot elements in the first conventional example.

FIG. 19 is a configuration diagram of a slot array antenna in a second conventional example.

FIG. 20 is a configuration diagram of a slot array antenna in a third conventional example.

FIG. 21 is a sectional view of a slot array antenna in a third conventional example.

[Explanation of symbols]

 1a, 1b Upper and lower conductor flat plates (flat plate waveguide) 2 Dielectric plate 3 Coaxial waveguide converter 4 Coaxial line 5 Slot element 6a, 6b Slot 7 End conductor plate 8 Conductor middle plate 9 Absorber 10 Slow wave material 11 Rectangular Waveguide 12 Branched Waveguide 13 Coupling Hole 14 Conductor Plate 15 Rectangular Waveguide for Feeding 16 H-Side Fan Horn 17 Dielectric Plano-Convex Lens

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[Procedure amendment]

[Submission date] September 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029]

[Equation 3]

Claims (7)

[Claims] 1. A pair of two facing each other at a required interval.
A flat plate waveguide composed of a single flat conductor plate, and a cylindrical wave or a plane wave propagating between the flat conductor plates, and a plurality of slot elements cut into the flat conductor plates of the flat plate waveguide. And a feed mechanism for feeding a cylindrical wave or a plane wave to the flat plate waveguide, and the radiation beam is radiated from each slot element cut into a conductor flat plate. Circularly polarized radio waves are generated using two slot slots that radiate wave radio waves and are arranged in a shape of a, a shape of a c or a cross, and a pair of slot elements are arranged. The slot array antenna is characterized in that the radiation direction of the circularly polarized radio wave is adjusted to be different from the normal direction of the flat waveguide. 2. The slot array antenna according to claim 1, wherein the flat waveguide has a fan shape with an apex angle smaller than 180 degrees, and a cylindrical wave feeding mechanism is provided in the vicinity of the apex of the flat fan waveguide. Further, the slot array antenna is characterized in that the radiation direction of the circularly polarized radiation beam is inclined from the normal direction of the fan-shaped plate waveguide to the apex direction of the fan-shaped plate waveguide. 3. The slot array antenna according to claim 2, wherein a conductor plate is provided on a side surface including the apex of the fan-shaped flat plate waveguide. 4. The slot array antenna according to claim 1, wherein the phase difference between the linearly polarized radio waves radiated from the two slots of the slot pair is 90 degrees in the required beam radiation direction. A slot array antenna characterized in that the arrangement interval of individual slots is set. 5. The slot array antenna according to claim 1, wherein two polarization planes of linearly polarized radio waves radiated from the two slots of the slot pair are orthogonal to each other in a required beam radiation direction. A slot array antenna characterized by arranging slots. 6. The slot array antenna according to claim 1, wherein the two slots are arranged so that the amplitudes of linearly polarized radio waves radiated from the two slots of the slot pair are equal in a required beam emission direction. The slot array antenna is characterized by setting the size of. 7. The slot array antenna according to claim 1, wherein the flat plate waveguide has a rectangular shape, a plane wave feeding mechanism is provided on one side of the rectangular flat plate waveguide, and a circularly polarized radiation beam is radiated. A slot array antenna, characterized in that the direction is inclined from the normal direction of the rectangular flat plate waveguide to the feeding mechanism side of the rectangular flat plate waveguide.