JPS60178707A - Slot array antenna system - Google Patents

Abstract

PURPOSE:To reduce the weight of a reflecting plate, to reduce the total weight of a slot array antenna and at the same time to reduce the load of a rotary drive system as well as the weight at the installing area of said antenna, by using a synthetic resin material to produce the reflecting plate and also providing a reflecting layer consisting of a conductor into the resin material or on its surface. CONSTITUTION:A reflecting plate 5 is made of a synthetic resin material such as fabric reinforced plastic FRP and molded with its plane plate folded in the direction orthogonal to the lengthwise direction at a prescribed angle. The reflecting amount is decided at a reflection part 5b by burying a thin metallic plate 5c at the middle of the part 5b in its thickness direction. The electromagnetic wave radiated from a slot waveguide 1 is made incident on the plate 5 after passing through dielectric plates 3a and 3b. Then the electromagnetic wave is reflected by a reflecting layer consisting of the plate 5c and travels toward the front of an antenna. In such a constitution, the total weight of the plate 5 is reduced. This also reduces the thickness of a channel member 2 which supports the plate 5. Therefore the total weight of a slot array antenna can be reduced.

Description

Detailed Description of the Invention "Industrial Field of Application λ The present invention relates to a slot-array antenna device suitable as an antenna for a marine radar, a relay device, etc., and in particular, it relates to a slot-array antenna device that is equipped with a dielectric waveguide mechanism and is small and lightweight. A slot designed to
The present invention relates to an array antenna device.

f. Prior Art Slot array antenna devices are smaller and lighter than parabolic fist antennas and the like, and are therefore often used in marine radars that need to be mounted on masts and the like. However, with only a slot waveguide, a directional beam can only be formed within a plane containing the tube axis of the slot waveguide (hereinafter referred to as the horizontal plane), and a directional beam can only be formed in a plane perpendicular to the horizontal plane (hereinafter referred to as the vertical plane). ) cannot form a directional beam in the vertical plane, so a horn is usually attached to obtain a directional beam in the vertical plane.
It is used. Therefore, even though it is not as sharp as a parabolic fist antenna, when trying to obtain a sharp beam, the weight increases and the aperture area becomes large, which has the drawback of increasing the influence of wind pressure when used outdoors. In particular, the issue of wind pressure is extremely important for marine radars used on windy seas, as this has a great effect on not only the strength of the radar itself but also the rotational drive system.

In response, the applicant has created a slot that is equipped with a dielectric waveguide mechanism and a small reflector, and by replacing the horn with a small reflector to reduce the size and weight and reduce the opening area. - Proposed an array fist antenna device (Japanese Patent Application Laid-open No. 31.205/1982).

FIGS. 1 and 2 show an example of this slot array antenna device. The antenna device shown in these figures has grooves 2 in the web of the channel member 2.
a, and the slot waveguide 1 is inserted and fixed into the groove 2a, and the slot waveguide 1 is placed at the front end of the slot waveguide 1, with a space in front of the front end in between, and the plate thickness is sufficient compared to the wavelength used. A dielectric waveguide mechanism 3 consisting of a pair of thin dielectric plates 3a and 3b is provided protrudingly, and the vicinity of the base of the dielectric plates 3a and 3b is transmitted through the outside of the pair of dielectric plates 3a and 3b. A reflecting plate 4 that reflects emitted electromagnetic waves is provided at the opening of the channel member 2.

The channel member 2 is made of a metal plate, supports the waveguide 1, the dielectric waveguide mechanism 3, and the reflection plate 4, and acts electrically in the same manner as a waveguide.

In order to reduce the electromagnetic waves trapped in the slope, the dielectric plates 3a and 3b are thin enough, for example, 1/10 Å or less, to reduce the electromagnetic waves that are trapped inside the slope, and are arranged approximately parallel to each other or with their tips slightly close to each other. and use it.

The thickness of this plate needs to be thinner as the dielectric constant increases.For example, if the dielectric constant is about 2.8, it should be 0.07
It will be 8 pieces.

The length L of the dielectric plates 3a and 3b in the front-rear direction is suitably about several times the wavelength. Also, a dielectric plate 3a.

3b is set to 1/28 or more in order to prevent power radiation from the slot waveguide 1 from being suppressed at the opening of the channel member 2. In this example, the distance between the outward facing surfaces is 067B.

The reflecting plate 4 is made of a metal plate like the channel member 2 described above. The sidelobe level of this reflector 4 decreases as the length of the plate increases, but as the length of the plate increases,
The wind pressure increases accordingly.

Therefore, it is desirable to set the wavelength to about twice the wavelength used.
．． There are 56 people. Further, the opening angle θ of the reflecting plate is determined by experiment, taking into account the incident angle of the electromagnetic waves passing through the dielectric plate and the wind pressure. In this example, the opening angle θ is 25 degrees.

This slotted fist array antenna device is capable of transmitting electromagnetic waves emitted from the waveguide 1 at a small angle with respect to the horizontal plane.

The inward surfaces (opposing surfaces) of the dielectric plates 3a and 3b reflect the radiation and guide it forward, and the radiation emitted at a large angle is reflected forward by the reflection plate 4, so that it is directed forward. The radiated electromagnetic energy is increased to form a directional beam and the sidelobe level is reduced.

In this case, the first reflector 4 only needs to reflect the electromagnetic waves emitted from the dielectric base at a large angle, so it can be short and the opening area can be made smaller than that of conventional horns. For example, in the case of a conventional horn type, the aperture height is more than four times the wavelength used, but in the case of this slot Φ array antenna device, it is only about twice the wavelength, making the aperture area smaller. I can do it.

The slot array shown in FIGS. 1 and 2 above
Although the antenna device itself is fully usable, depending on the application, it may be required to reduce the total weight in order to reduce the burden on the rotational drive system, reduce the weight burden on the installation location, etc. This is especially necessary for marine rakes.

By the way, in the above-mentioned antenna device, since the reflector is made of a metal plate, the reflector itself is heavy, and the channel member is also formed thick in order to support the reflector. Therefore, in order to reduce the weight, it is possible to make the reflector thinner, but this is difficult to realize because of the influence of wind pressure and other factors, which pose problems in terms of strength.

Even in the above-mentioned slot array antenna device with a dielectric waveguide mechanism, which is constructed to be lighter than a general antenna, further weight reduction is not easy due to the structure.

Purpose of the Invention The present invention has been made in view of the above problems, and it reduces the weight of the reflector without reducing its strength, reduces the total weight, reduces the burden on the rotational drive system, and reduces the weight of the installation location. An object of the present invention is to provide a slot array antenna device that reduces burden.

rConfiguration of the invention j In order to achieve the above object, the configuration of the present invention includes a pair of dielectric plates having a thickness sufficiently thin compared to the wavelength used, at the front end of the slot waveguide, sandwiching a space in front of the front end. In the slot array antenna device, the upper lip reflection The plate is characterized by being formed by providing a reflective layer made of a conductor inside or on the surface of a synthetic resin plate.

In this way, by forming the reflecting plate from synthetic resin, it is possible to maintain the necessary strength and reduce the weight. Furthermore, by providing a reflective layer by forming conductors in layers on a synthetic resin plate, it is possible to reflect electromagnetic waves without increasing the weight.

This reduces the total weight of the antenna device, reduces the weight burden at the installation location, and also reduces the burden on the rotational drive system, making it possible to downsize the chain string.

“Example J Embodiments of the present invention will be described with reference to the drawings.

In the first embodiment of the slot array antenna device of the present invention shown in FIGS. 3 and 4, a groove 2a is provided in the web of a channel member 2, and a slot waveguide l is inserted and fixed into the groove 2a. At the front end of the slot waveguide 1, a dielectric waveguide mechanism 3 consisting of a pair of dielectric plates 3a and 3b, the thickness of which is sufficiently thin compared to the wavelength used, is inserted across a space in front of the front end. Set up.

Further, a reflecting plate 5 that reflects electromagnetic waves transmitted through the vicinity of the bases of the dielectric plates 3a and 3b and emitted is placed outside the pair of dielectric plates 3a and 3b at the opening of the channel member 2. It is provided and configured separately from 2. Note that, except for the reflection plate 5, the other components are the same as those shown in FIG. 1 above, so the description will not be repeated.

The reflecting plate 5 is made of a synthetic resin material such as FRP (fiber reinforced plastic), and is molded into a flat plate bent at a predetermined angle in a direction perpendicular to the longitudinal direction. This angle θ is
The settings are similar to the example shown in FIG. 1 above, and in this example,
It is 25 degrees.

The base side of this reflection plate 5 is attached to a mounting portion 5 to the channel member 2.
a, and the tip end side is an electromagnetic wave reflecting part 5b. The attachment portion 5a is fixed to the outer surface of the channel member 2 with an adhesive or the like, and supports the reflection portion 5b.

The reflective part 5b has a thin metal plate 5C embedded in the middle part in the thickness direction to form a reflective layer.

The length of the reflecting section 5b is set to about twice the input wavelength, similar to that shown in FIG. 1 above.

In this example, the number of people is 1.56.

As shown in FIG. 5, this metal plate 5C has multiple through holes 5d. This through hole 5d not only reduces the weight of the metal plate 5C, but also allows the synthetic resin materials on the upper and lower sides of the metal plate 5C buried in the intermediate portion to pass through and bond to each other when forming the reflective plate 5. do. Therefore, the reflecting portion 5b is strongly formed using the metal plate 5c as a reinforcing material.

The size of the through hole 5d is limited in the direction orthogonal to the electric field vector of the polarized wave used in order to prevent the electromagnetic wave to be reflected from passing backward. That is, the wavelength is set to 1/2 or less of the wavelength of the electromagnetic waves used.

In the case of this embodiment, in order to obtain a sufficient reflection effect, the through hole 5d
is formed in the shape of a circular hole with a diameter of 3 m11. However,
The through hole 5d is not limited to a circular hole, but may be a square hole or a slit shape.

In such a configuration, the electromagnetic waves radiated from the slot waveguide l pass through the dielectric plates 3a and 3b and reach the reflection plate 5.
When the light is incident on the metal plate 5c, it is reflected by the reflective layer made of the metal plate 5c and travels in the forward direction of the antenna. At this time, metal plate 5C
Although a through hole 5d is provided, this through hole 5d has a small diameter so that it does not interfere with the reflection of electromagnetic waves, especially horizontally polarized components.

Further, according to the above configuration, most of the reflector 5 is formed of eave synthetic resin, and the remaining metal portion is also extremely thin, so that the total weight of the reflector 5 is reduced.

As a result, the thickness of the channel member 2 that supports the reflector plate 5 can be made thinner, and the overall weight of the antenna can be reduced.

Therefore, the burden of rotating by the one-rotation drive system is reduced, and the rotation drive system can be downsized. Furthermore, when used in a marine radar or the like, the weight reduction makes it possible to reduce the weight burden of the installed mast, etc.

In this embodiment, the channel member 2 and the reflecting plate 5 are separate bodies, but they may be formed integrally.

Next, in the second embodiment of the present invention shown in FIG. 6, a groove 2a is provided on the non-projecting side of the parallel web of the channel member 2, and the slot waveguide 1 is fixed to the groove 2a. ,
In addition, a dielectric plate 3a is provided on the outside of the parallel piece of the channel member 2.
, 3b are attached to the base, and a reflecting plate 5 is attached to the outside thereof.

In this embodiment, dielectric plates 3a and 3b are sandwiched between the parallel pieces of the channel member 2 and the reflecting plate 5. The fixation can be done not only by adhesive but also by screwing the parallel pieces of the channel member 2 together. The reflector 5 has basically the same structure as the first embodiment, except for the size of the mounting portion 5a.

Further, in the third embodiment of the present invention shown in FIG. 7, a groove 2a is provided on the non-projecting side of the parallel piece of the web of the channel member 2, and the slot waveguide 1 is fixed to the groove 2a.
In addition, a dielectric plate 3a is provided on the outside of the parallel piece of the channel member 2.
, 3b are attached, and a curved reflecting plate 6 is attached to the outside thereof.

The reflector 6 of this embodiment is the reflector 5 of the above-mentioned Embodiment 1.2.
Similarly, the mounting portion 6 is integrally formed of synthetic resin material.
a and a reflecting section 6b. A metal plate 6C provided with a large number of through holes 6d is buried inside the reflecting portion 6b.

Further, this reflecting plate 6 has a parabolic cross section and a parabolic surface in the longitudinal direction. If a paraboloid is set so that the source of the electromagnetic waves incident on the reflector plate 6 is located at the focal point, the reflected electromagnetic waves can be made substantially parallel.

In each of the embodiments described in , if it is necessary to further increase the strength of the reflector, ribs may be provided at appropriate locations in the longitudinal direction of the reflector, extending from the receiving part to the reflecting part, or , an overlay may be attached.

Furthermore, in each of the above embodiments, the reflective layer is constructed of a metal plate provided with a large number of through holes, but the reflective layer is not limited to this, and can also be constructed by embedding a metal net in a synthetic resin material. moreover,
A conductive layer may be formed on the surface of the reflective plate to serve as a reflective layer.

In these cases and each of the above examples, the reflective layer is
It does not need to be porous or reticulated, and may be a uniform layer.

In each of the above embodiments, the dielectric plates are arranged substantially parallel, but the dielectric plates can also be arranged non-parallel in the direction in which the tips approach each other. According to such an arrangement, side lobes can be reduced.

Effects of the Invention λ As explained above, the present invention has a structure in which the reflective plate is formed of a synthetic resin material and a reflective layer made of a conductor is provided in or on the surface of the synthetic resin material, thereby reducing the strength. This has the effect of reducing the weight of the reflector without causing any damage, reducing the total weight, reducing the burden on the rotational drive system, and reducing the weight burden on the installation location.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a slot array antenna device equipped with a dielectric waveguide mechanism, Fig. 2 is a sectional view thereof, and Fig. 3 is a first embodiment of the slot array Φ antenna device of the present invention. Fig. 4 is an enlarged sectional view of the main part, Fig. 5 is a perspective view showing the
The figure is a perspective view showing the structure of a reflector that constitutes the above embodiment;
FIG. 6 is an enlarged sectional view of a main part showing a second embodiment of the present invention, and FIG. 7 is an enlarged sectional view of a main part showing a third embodiment of the invention. 1...Slot waveguide 2...Channel member 2a...Groove portion 3...Dielectric waveguide mechanism 3a, 3b...Dielectric plate 4.5.6...Reflector plate 5a, 6a ...Mounting parts 5b, 6b...Reflecting parts 5c, 6c...Metal plates 5d, 6d...Through hole Applicant Tokyo Keiki Co., Ltd. Agent Patent attorney Iwao Mishina Figure 6 and Figure 7 Procedure amendment Written (self-motivated) IS Date 1, May 1985, Indication of the incident Patent Application No. 59-34710? 9 Title of the invention Slot φ array antenna device 3, Person making the amendment Relationship to the case Patent applicant 4, Agent 〒220 5. Details of the invention in the claims column of the specification to be amended Explanation column (a) On page 3, line 19 of the specification, the phrase "at the front end of the waveguide 1, with a space in front of the front end in between" has been replaced with "the waveguide 1
In front of, across the space in front of,'' is corrected. (b) On page 7, line 13 of the specification, [At the front end of the waveguide,
The phrase "across the space in front of the front end," should be corrected to "in front of the waveguide, across the space in front of the waveguide." (c) On page 8, line 17 of the specification, the phrase "at the front end of the waveguide l, across the space in front of the zero end" has been replaced with "at the front end of the waveguide l, across the space in front of the zero end""With a space in between," he corrected. Claims as amended above: (1) A pair of dielectric plates are protrudingly provided in front of the slot waveguide, sandwiching a space in front of the slot waveguide, and the plate thickness is sufficiently thin compared to the wavelength used, and In the slot array antenna device, a reflecting plate is provided on the outside of the pair of dielectric plates to reflect electromagnetic waves transmitted through the vicinity of the base of the dielectric plates and emitted, 1-. A slot array antenna device characterized in that it is formed by providing a reflective layer made of a conductor inside or on the surface of a resin plate. (2) The reflective layer is formed by embedding a metal plate with a large number of through holes inside a synthetic resin plate.
The slot-array φ antenna device described in . (3) The slot according to claim 1, wherein the reflective layer is formed by embedding a metal net inside a synthetic resin plate.
Array antenna device.

Claims (3)

[Claims] (1) At the front end of the slot waveguide, a pair of dielectric plates, whose thickness is sufficiently thin compared to the wavelength used, are provided protrudingly across a space in front of the front end, and the pair of dielectric plates are In the Slon 1" array antenna device, which is provided with a reflective plate on the outside that reflects electromagnetic waves transmitted through the vicinity of the base of the dielectric plate and emitted, the reflective plate described in 4. A slot array antenna device characterized in that it is formed by providing a reflective layer made of a conductor. (2) The reflective layer is formed by embedding a metal plate with a large number of through holes inside a synthetic resin plate.
The slot array antenna device described in . (3) The slot according to claim 1, wherein the reflective layer is formed by embedding a metal net inside a synthetic resin plate.
Array fist antenna device.