JPH03219707A - Radial line slot antenna - Google Patents

Abstract

PURPOSE:To obtain a maximum antenna efficiency by forming an adjustment body or an adjustment ring having a side face along with a spiral line of Archimedes to a center or a circumferential part of a slot plate so as to make a radio wave of a radial line slot antenna in axis-symmetry. CONSTITUTION:An equi-phase plane when a radio wave reaching a slot 2 from a remote location is a concentric radio wave toward the center in a radial guide line 4 indicates a phase difference of lambdag (wavelength in radial guide path) in a center feeding section while being affected with lots of slots arranged in a spiral line of Archimedes. A conductor of a shape close to equi-phase is formed to the feeding part so as to be coaxial to the center of a slot plate 1 to make the phase and the amplitude to be in axial-symmetry. Thus, an optimum angle between the spiral line formed by the slot plate 1 and the spiral line side face of the adjustment body 8 is obtained in advance and the adjustment body 8 is fixed to the plate 1. Then in the case of an adjustment ring 9, the optimum angle between the spiral line formed to the slot plate 1 and the adjustment ring 9 is measured actually and fixed while the plate 1 is turned so that the wall face of the radial guide path 4 of the circumferential part and the equi-phase plane are made coincident.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a radial line slot antenna using a radial waveguide used in the SHF and EHF bands.

<Prior Art> Traditionally, bowl-shaped parabolic antennas have been used in satellite communications and the like, but recently, radial line slot antennas have been proposed in place of the parabolic antennas.

As this radial line slot antenna, for example, there is one shown in Japanese Patent Publication No. 1964-1985. That is, in a radial waveguide composed of upper and lower disc-shaped conductors arranged oppositely at equal intervals, the upper conductor is characterized by sequentially disposing V-shaped slots located on a predetermined spiral line. It is a circularly polarized planar array antenna.

<Problems to be Solved by the Invention> However, when the slots are arranged on a spiral line, that is, on a helix, as in the conventional antenna described above, the axial symmetry of the fundamental propagation mode inside the antenna is near the beginning of the spiral. It gets chaotic near the end. That is, there is a problem in that the phase and amplitude within the radial waveguide vary greatly, reducing the gain of the antenna.

An object of the present invention is to provide a radial line slot antenna that has excellent axial symmetry and can obtain sufficient gain.

<Means for Solving the Problems> The present invention has been made to solve the above problems.
In a radial line slot antenna in which a radial waveguide is formed by a slot plate having a large number of slots and a conductor facing the slot plate, the wavelength in the radial waveguide is λg.

When 0<C≦1, the surface along the Archimedean spiral with the starting point at a distance of δ from the center of the slot plate in the radial direction and the ending point at a distance of δ+C×λg. This is a radial line slot antenna characterized in that an adjustment member having the above-mentioned adjustment member is attached to the center or peripheral portion of a slot plate.

Further, in a radial line slot antenna in which a radial waveguide is formed by a slot plate having a large number of slots, a conductor facing the slot plate, and a partition plate disposed between the slot plate and the conductor. , when the wavelength in the radial waveguide is λg and 0<C≦1, the starting point is a point located at a distance of δ from the center of the partition plate in the radial direction, and the ending point is a point located at a distance of δ + C × λg. This is a radial line slot antenna characterized in that an adjustment member having a surface along an Archimedean spiral is attached to the center of a partition plate.

<Function> According to the radial line slot antenna of the present invention, the adjustment member having a surface along the Archimedean spiral is attached to the center or peripheral part of the slot plate so as to be coaxial with the center of the slot plate. The adjustment member can be fixed at an angle that does not disturb the axial symmetry of the fundamental propagation mode in the radial waveguide, and the emitted radio waves are axially symmetrical, that is, the phase is aligned.
In addition, the amplitude fluctuation is small, and the above-mentioned problem is solved.

<Example> The present invention will be explained in detail using examples.

FIG. 1 is an explanatory diagram of a radial line slot antenna according to the present invention. In the figure, (1) is a slot plate, and this slot plate (1) is a metal disk, which has a plurality of holes formed by etching or the like. slot (2). In addition, (3) is a frame, which is made by drawing the peripheral edge of a metal disk.The slot plate (1) is joined to this peripheral edge, sealed with epoxy resin, etc., and a radial A waveguide (4) is formed. A coaxial (5) and an adjusting body (8) are placed approximately in the center of the slot plate (1).
) is attached.

Further, an adjustment ring (9) is arranged around the periphery of the frame (3). A radome (6) is attached above the slot plate (1) to prevent rain and the like from entering. This radome (6) is made of slippery Teflon material to prevent snow from accumulating, and its periphery is overlapped and sealed with the slot plate (1) and frame (3). Moreover, a spacer (7) made of foamed polystyrene or the like may be laminated between the radome (6) and the slot plate (1), if necessary.

Here, the arrangement pattern of the slots (2) provided in the slot plate (1) will be explained.

As shown in FIG. 2, the slot (2) has the wavelength of the axisymmetric propagation mode in the radial waveguide (4), where λg is
The first point at a distance of ΔX from the center 0 of the slot plate (1), the second point at a distance of ΔX+λg, Δχ+2×λg
The third point at a distance of , the fish school obtained in the same way,
That is, they are arranged on an Archimedean spiral passing through the school of fish given at intervals of λg. In other words, slot (2
) is the polar coordinate (R, θ) of the midpoint of the equation R=Δχ+λg×
The slots (2) are sequentially arranged so as to satisfy θ/2π.

Next, the adjustment body (8) and adjustment ring (9) will be explained.

As shown in FIG. 3, the adjustment body (8) has a slot plate (1
) is the starting point at a distance of δ from the center of δ+C×λ
It is a plate-shaped conductor or dielectric with a side surface (8a) along an Archimedean spiral ending at a point at a distance of g (0<C50).

The adjustment ring (9) has a starting point at a distance d from the center as shown in FIG.
A conductor or dielectric with a surface along the Archimedean spiral ending at a point at a distance of It is rolled up and its side (9a)
It's sloped. The adjustment body (8) is formed at the center, that is, the power feeding part, and the adjustment ring (9) is formed at the periphery, and either one is sufficient to make the propagation mode in the radial waveguide axially symmetrical. be.

This function will be explained in the case where the adjustment body (8) is a conductor. When a radio wave that reaches the slot (2) from a distance becomes a concentric radio wave heading toward the center within the radial waveguide (4), the equiphase front is formed by a large number of slots ( 2), λ at the central feed section
It appears as a phase difference of about 100 g. Resolving this,
In order to make the phase and amplitude axially symmetrical, a conductor having a shape close to the above-mentioned equiphase plane is formed in the power feeding section so as to be coaxial with the center of the slot plate. At this time, the shape of the adjustment body,
The shapes of the equiphase surfaces do not necessarily match. Therefore, the optimum angle between the spiral formed on the slot plate (1) and the side surface of the spiral of the adjustment body (8) should be experimentally determined, and the adjustment body (8) can be inserted into the slot at the obtained angle. Fix it to the board (1). In the case of the adjustment ring (9), the radial waveguide (4
) Insert the slot plate (
The optimum angle between the spiral formed in 1) and the adjustment ring (9) is actually measured while rotating the slot plate (1), and the obtained angle is fixed.

In this way, by forming an adjustment body or adjustment ring with a side surface along the Archimedean spiral in the center or periphery of the slot plate (1), the radio waves of the radial line slot antenna can be made axially symmetrical and maximized. antenna efficiency can be obtained.

FIG. 5 shows another embodiment. In the radial line slot antenna of the embodiment described above, a partition plate (lO) is disposed approximately in the center of the radial waveguide (4), and the upper layer waveguide is (4a) and a lower layer waveguide (4b) are formed into sections, and a folded part is formed at the end of the antenna. In this case, the adjustment body (8) is similarly attached to the partition plate (10). . This makes it possible to make the radio waves radiated from the radial line slot antenna axially symmetrical and obtain maximum antenna efficiency.

Next, still another embodiment will be described using FIGS. 6 to 8.

In this embodiment, the above-mentioned adjustment body (8) and adjustment ring (9) are used.
In addition, an adjustment post (11) is provided.

As shown in FIGS. 6 to 8, the adjustment column (11) is
It is located at the center, and the distance between the coaxial shaft (5) and the tip (lla) of the adjustment column can be adjusted with a screw. In addition, the adjusting body (8) is arranged in an Archimedean spiral whose starting point is a point at a distance of δ from the center of the slot plate (1) and ends at a point at a distance of δ0C×λg (0<C50), as described above. side (8a) along
It is a curved ball-shaped conductor, radio wave absorber, or dielectric material.

Further, as described above, the adjustment ring (9) also has a starting point at a distance d from the center 0, as shown in FIG.
A conductor, radio wave absorber, or dielectric material that has a surface along the Archimedean spiral whose end point is a point at a distance of xλg (0<C50).To be more specific, it is a striped (band-shaped) conductor or radio wave. The absorber or dielectric material is wound along the spiral line. The adjustment column (11
) is located at the power supply section, the adjustment body (8) is located at the center, and the adjustment ring (9) is located at the center.
is formed on the periphery, and the adjustment column (11) mainly functions to adjust impedance, whereas the adjustment body (
8) and the adjustment ring (9) function to make the propagation mode in the radial waveguide axially symmetrical.

This function will be explained in the case where the adjustment ring (9) is a conductor. When a radio wave that reaches the slot (2) from a distance becomes a concentric radio wave heading toward the center within the radial waveguide (4), the equiphase front is formed by a large number of slots ( 2), C at the central feeder
A phase difference of approximately ×λg appears. In order to solve this problem and make the phase and amplitude axially symmetrical, a conductor having a shape close to the above-mentioned equiphase plane is formed in the peripheral portion so as to be coaxial with the center of the slot plate. At this time, adjustment ring (9)
The shape of and the shape of the equiphase surface do not necessarily match. Therefore, the optimum angle between the end point of the spiral of the slot pattern formed on the slot plate (1) (not shown) and the end point of the spiral of the adjustment ring (9) has been experimentally determined and obtained. Fix the adjustment ring (9) to the slot plate (1) at the specified angle.

The same applies to the adjustment body (8) in FIG.

In this way, by forming the adjusting body (8) or the adjusting ring (9) having a side surface along the Archimedean spiral in the center or the periphery of the slot plate (1), the radio waves of the radial line front antenna can be adjusted. By making it axially symmetrical, the maximum antenna efficiency can be obtained, and the impedance can be matched by the adjustment column (11).

<Effects of the Invention> The radial line slot antenna of the present invention has excellent axial symmetry due to the adjustment member attached to the slot plate, and can obtain high gain performance.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway explanatory diagram, FIG. 2 is an explanatory diagram showing the pattern of slots arranged on the slot 7) plate, and FIG. FIG. 4 is an explanatory diagram of the adjustment ring, and FIGS. 5 to 8 are explanatory diagrams showing other embodiments. (1)...Slot plate (2)...Slot (3)
... Frame (4) ... Radial waveguide (5)
... Coaxial (6) ... Radome (7) ...
Spacer (8)...Adjustment body (9)...Adjustment ring
(10)...Partition plate (11)...Adjustment column (
12)... Adjustment hole patent application Hitotoppan Printing Co., Ltd. Representative Kazuo Suzuki Figure 1 Figure 2 Figure 5

Claims (4)

[Claims] (1) In a radial line slot antenna in which a radial waveguide is formed by a slot plate having a large number of slots and a conductor facing the slot plate, the wavelength in the radial waveguide is set to λg, 0<C≦1. In this case, an adjusting member having a surface along an Archimedean spiral with a starting point at a distance of δ from the center of the slot plate in the radial direction and an end point at a distance of δ + C × λg is attached to the slot plate. A radial line slot antenna characterized by being attached to the center or the periphery. (2) A radial line slot antenna formed by forming a radial waveguide with a slot plate having a large number of slots, a conductor facing the slot plate, and a partition plate disposed between the slot plate and the conductor. When the wavelength in the radial waveguide is λg and 0<C≦1, the starting point is a point at a distance of δ from the center of the partition plate in the radial direction, and the ending point is a point at a distance of δ+C×λg. A radial line slot antenna characterized in that an adjustment member having a surface along an Archimedean spiral is attached to the center of a partition plate. (3) The radial line slot antenna according to claim 1, characterized in that an adjustment post and an adjustment hole for adjusting the impedance and the distance to the coaxial power feeding section are installed approximately at the center of the slot plate. (4) The radial line slot antenna according to claim 2, characterized in that an adjustment post and an adjustment hole are installed approximately in the center of the partition plate to adjust the distance to the coaxial power feeding section and the impedance.