JPH10284929A - Waveguide slot antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge a visual field range by means of simple configuration by providing a waveguide where plural slots which cross with a tube axis are generated by means of a dimension interval being smaller than a half of the in-tube wave length of a usage frequency, a reflection body arranged in a waveguide terminating part in one end of the waveguide and a power feeding means for supplying radio wave from the other end of the waveguide. SOLUTION: A waveguide slot antenna is constituted by generating the plural slots 10a crossing with the tube axis by the dimension interval being smaller than a half of the in-tube frequency of the usage frequency in a square waveguide 10 and by providing the reflection body 11 in the waveguide terminating part of the square waveguide 10. Incident wave which is made incident the square waveguide 10 and reflection wave reflected by the reflection body 11 are respectively generated towards two different directions since an antenna beam direction is inclined in a direction opposite to the propagating one against the longitudinal line of the tube axis by a prescribed angle by the actuation of the slots 10a so that the wide visual field range is secured. As a result, the time of scanning for scanning a desired scanning range is reduced and scanning time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide used as a radiating element of a ground radar such as a ship radar, a harbor radar, a weather radar, and an array antenna for a flying object mounted on a flying object such as an artificial satellite. It relates to a tube slot antenna.

[0002]

2. Description of the Related Art In general, a waveguide slot antenna of this type has a narrow surface (E) as shown in FIG.
A plurality of slots (not shown, for the sake of illustration, not shown) intersecting with the tube axis on one of the surface (a surface) or the wide surface (H surface) with an interval dimension of half the guide wavelength of the working frequency, A resonance type in which a reflector 2 is mounted and arranged at the end of the waveguide is known. Then, a radio wave of a predetermined frequency is supplied to the other end of the rectangular waveguide 1 via the feeder 3, and the radio wave propagates in the waveguide 1 and is directed from a slot (not shown) in a directional direction. It is radiated toward.

A radio wave incident from one end of the rectangular waveguide 1 is reflected by a reflector 2 at the end of the waveguide, and is similarly radiated from a slot (not shown) in a directional direction. Thereby, the antenna beam C of the incident wave and the reflected wave is superimposed and emitted from the slot of the rectangular waveguide in the same direction.

However, in the above-described waveguide slot antenna, the antenna beam directions of the incident wave and the reflected wave radiated from the slot (not shown) are superimposed and radiated in the same direction, and the visual field per slot is obtained. Since the range is relatively small, there is a problem that it takes a relatively long time to scan a wide range. The field of view of the antenna beam C is a major issue in improving radar performance.

[0005]

As described above, in the conventional waveguide slot antenna, the field of view of the antenna beam radiated from the slot is restricted, and it takes a long time to scan a wide range. There is such a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a waveguide slot antenna which has a simple configuration, has a wider field of view, and has a shorter scanning time. I do.

[0007]

According to the present invention, a plurality of slots intersecting with the tube axis have a half of the guide wavelength of the operating frequency.
A waveguide formed at a smaller dimensional interval, a reflector provided at one end of the waveguide at the end of the waveguide, and power supply means for supplying a radio wave from the other end of the waveguide. This constitutes a waveguide slot antenna.

[0010] According to the above configuration, the incident wave incident on the waveguide and the reflected wave reflected by the reflector have the antenna beam direction set to the propagation direction with respect to the vertical line of the tube axis by the action of the slot. They are inclined at a predetermined angle in opposite directions, and are formed in different directions. As a result, an antenna beam is formed in two directions at the same time by the incident wave and the reflected wave, and a rapid scanning of a wide range becomes possible.

Further, according to the present invention, there is provided a waveguide in which a plurality of slots intersecting with the tube axis are formed at a dimension interval larger than one half of the guide wavelength of the operating frequency, and a waveguide at one end of the waveguide. A waveguide slot antenna was provided with a reflector provided with a tube end portion and a feeding means for supplying a radio wave to the other end of the waveguide.

According to the above structure, the incident wave incident on the waveguide and the reflected wave reflected by the reflector have the antenna beam direction in the propagation direction with respect to the vertical line of the tube axis by the action of the slot. Each of them is inclined at a predetermined angle and formed in different directions. Thereby, an antenna beam in two directions is simultaneously formed by the incident wave and the reflected wave, and the scanning range can be expanded.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a main part of a waveguide slot antenna according to an embodiment of the present invention. In a rectangular waveguide 10, for example, a plurality of radio wave radiation slots 10a are cut at an interval D on an H surface. It is formed by processing. A reflector 11 is attached to one end of the rectangular waveguide 10 at the end of the waveguide, and a power supply unit 12 is connected to the other end of the rectangular waveguide 10 on the radio wave incident side (see FIG. 2).
The reflector 11 is formed of a material having excellent reflectance, for example, of the same quality as the rectangular waveguide 10.

Slot 1 formed in the rectangular waveguide 10
The dimension interval D of 0a is set to, for example, a dimension smaller than half the guide wavelength of the operating frequency in consideration of the scanning range, the radio wave characteristic, and the radar characteristic.

According to the above configuration, when a radio wave fed to a predetermined power via the feed section 12 enters the rectangular waveguide 10, the incident wave is propagated as shown by a solid line in FIG. Are reflected as shown by the broken lines in the figure and are respectively radiated from the slots 10a. On this occasion,
As shown in FIG. 2, the radio wave radiated from the slot 10a is such that the incident wave is in a direction opposite to the propagation direction with respect to the vertical line of the tube axis.
An antenna beam A is formed in a direction inclined by θ, and an antenna beam B is formed in a direction inclined by θ in a direction opposite to the propagation direction of the reflected wave with respect to the vertical line of the tube axis. Where 1
Antenna beams A radiated from the slots 10a
B is radiated in two different directions by an incident wave and a reflected wave, and a visual field in two directions is secured substantially simultaneously. As a result, the field of view per slot of the rectangular waveguide 10 is widened, the scanning range can be scanned with a small number of scans, and the scanning time is shortened.

As described above, the waveguide slot antenna has a plurality of slots 1 intersecting the tube axis in the rectangular waveguide 10.
The rectangular waveguide 10 is provided with a reflector 12 at the end of the rectangular waveguide 10 at a dimensional interval D smaller than half the guide wavelength of the operating frequency.

According to this, the incident wave incident on the rectangular waveguide 10 and the reflected wave reflected by the reflector 11 have their antenna beam directions changed with respect to the vertical line of the tube axis by the action of the slot 10a. Inclined at a predetermined angle in the direction opposite to the propagation direction,
Each is formed in two directions toward different directions, and a wide viewing range is secured. As a result, the number of scans for scanning a desired scan range can be reduced, the scan time can be shortened, and quick scan can be realized.

In the above embodiment, the slot 10
a has been described to be formed with a dimensional interval D smaller than one half of the guide wavelength of the operating frequency. However, the present invention is not limited to this. Even if it is configured to be formed with a larger dimensional interval, it is possible to radiate antenna beams in two directions in the same manner, and substantially the same effect is expected.

In this case, the radio wave radiated from the slot 10a forms an antenna beam in a direction inclined by a predetermined angle in the propagation direction with respect to the vertical line of the tube axis by the incident wave, and the reflected wave forms the antenna beam in the tube axis. An antenna beam is formed in a direction inclined by a predetermined angle in the propagation direction with respect to the vertical line.

In the above embodiment, the rectangular waveguide 1
Although the case where it is configured to be formed on the H plane of 0 has been described,
The present invention is not limited to this, and may be formed on, for example, the E surface. In this case, the H plane of the rectangular waveguide 10 is formed in a waveform.

Further, in the above embodiment, the reflector 11
Is described using the same material as the rectangular waveguide 10, but the present invention is not limited to this, and a material having an excellent reflectance different from that of the rectangular waveguide 10 may be used.

Further, in the above embodiment, the case where the present invention is applied to the rectangular waveguide 10 has been described. However, the present invention is not limited to this, and can be applied to waveguides of various shapes such as a circular waveguide. The same effect is expected. Therefore, it is needless to say that the present invention is not limited to the above-described embodiment, and that various modifications can be made without departing from the spirit of the present invention.

[0021]

As described above in detail, according to the present invention, it is possible to provide a waveguide slot antenna which has a simple structure, has a wider field of view, and has a shorter scanning time. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of a waveguide slot antenna according to an embodiment of the present invention.

FIG. 2 is a diagram showing a radiation state of the antenna beam of FIG. 1;

FIG. 3 is a view for explaining a problem of a conventional waveguide slot antenna.

[Explanation of symbols]

 10 ... rectangular waveguide. 10a Slot. 11 ... Reflector. 12 ... Power supply unit.

Claims (5)

[Claims] 1. A waveguide in which a plurality of slots intersecting with a tube axis are formed at a dimension interval smaller than one half of a guide wavelength of a working frequency, and a waveguide termination portion at one end of the waveguide. A waveguide slot antenna, comprising: a reflector provided; and a feeding unit for supplying a radio wave from the other end of the waveguide. 2. A waveguide in which a plurality of slots intersecting with the tube axis are formed at a dimension interval larger than one half of a guide wavelength of a working frequency, and a waveguide termination portion at one end of the waveguide. A waveguide slot antenna, comprising: a provided reflector; and a feeding unit that supplies a radio wave to the other end of the waveguide. 3. The waveguide slot antenna according to claim 1, wherein the reflector is formed of the same material as the waveguide. 4. The waveguide has a rectangular cross section,
4. The waveguide slot antenna according to claim 1, wherein a slot is formed in at least one of the E plane and the H plane. 5. The waveguide slot antenna according to claim 1, wherein the slot is formed by cutting.