JPH01248804A - Antenna system - Google Patents

Abstract

PURPOSE:To eliminate the need for an expensive stand and to reduce the cost of a device when the device is used, in a room while the reflecting plate of a reflector antenna can be molded only with bending by utilizing not the rotation surface of the parabola but a parallel moving surface as the reflecting surface of the reflector antenna. CONSTITUTION:In a parabola (Z=Y<2>/4F) having an off-setting quantity which is F, right and left ridge line parts 121 and 122 of a frame 12 are curved to a rear side along the curve (slanting line part) of a Y coordinate section (E<=Y<=E+D). On the other hand, upper and lower ridge line parts 123 and 124 of the frame 12 are linearly set. A reflecting plate 11 is composed of a comparatively soft member, when it is fitted to the frame 12, it is curved along the shape of the ridge line parts 121 and 122 and becomes the same reflecting surface as the curved surface obtained by moving the curve of the Y coordinate section in parallel. As a primary radiator 14, the primary radiator of the construction to arrange a radiation element linearly is prepared and provided on the off-setting position of the reflector antenna so that the arrangement direction of the radiation element can be along the parallel moving direction of the curve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to, for example, an antenna device for receiving satellite broadcasting.

(Prior Art) In general, antennas used in antenna devices for receiving satellite broadcasting use a part of a paraboloid of revolution as shown in Fig. 11, or a flap antenna (usually a parabolic antenna). The mainstream is an array antenna (usually called a planar antenna) that arranges a plurality of radiating elements and excites all of them as shown in FIG. 12.

For the former glue reflector antenna, for example, a hole is dug in the ground, a ball 1 is fixed with concrete 2, a direction adjustment @ 13 is attached to this ball 1, and a reflector 4 is attached to the ball 1 via this direction adjustment device. Installed by.

As shown in FIG. 13, the reflector antenna 4 is generally a paraboloid of revolution (
Offset reflector antennas that utilize the shaded area in the figure are often used. The offset type reflector antenna 4 is characterized by the fact that the reflector antenna 4 is almost perpendicular to the ground due to the offset, so it is less susceptible to the effects of snow accumulation, and the primary radiator 5, frequency converter 6, etc. located at the focal point The main point is that there is no blocking due to

Incidentally, the reflector antenna 4 is generally made by press-molding a metal plate or by molding a thermosetting resin into an SMC (Sheet
Moldino Compound) is often formed by molding.

However, the former press forming method has the problem of requiring advanced press technology that takes into account springback and the like in order to obtain accurate surface area.

Furthermore, in the case of the latter, for example, when aluminum foil is used as the reflective layer, care must be taken to prevent wrinkles, cracks, etc., and there is a problem in that it is difficult to mold.

Further, when an installation method of embedding the antenna device underground as shown in FIG. 11 is adopted, there are problems in that the antenna device becomes expensive and a large amount of construction cost is required. Therefore, by using the reflector antenna indoors, it may be possible to eliminate the need for installation work. However, the reflector antenna 4 has a circular or oval shape and is difficult to sit.
As shown in FIG. 14, a stand 7 is required in place of the ball 1. Therefore, even when the reflector antenna 4 is used indoors, although installation costs can be eliminated, the price of the antenna device cannot be reduced.

Note that the planar antenna shown in FIG. 12 has radiating elements arranged on a printed circuit board, so it is necessary to use a substrate material with low transmission loss. Therefore, in this case, there is a problem that the antenna itself becomes expensive and is difficult to adopt as an antenna for a home antenna device.

(Problems to be Solved by the Invention) As described above, in the conventional antenna device using the reflector antenna 4, molding the reflector antenna 4 requires advanced pressing technology or is difficult to mold. There was a problem.

Further, even when the reflector antenna is used indoors to save construction costs, an expensive stand is required, so there is a problem that the price of the antenna Si''11 cannot be lowered.

Therefore, the present invention does not require sophisticated press technology even when the reflector antenna is molded by press technology, and is easy to mold even when SMC molding is used.
Moreover, when used indoors, it is an object of the present invention to provide an antenna device in which the antenna can be easily installed without using an expensive stand, and the cost of the device can be reduced.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the antenna device of the present invention has a vertical flap antenna that manually moves along a curved line in a section deviated from the center line of a parabola. It has a shape in which the curved surface obtained by this is the reflective surface. Further, the primary radiator has a configuration in which radiating elements are arranged linearly. The primary radiator is supported by a frequency converter, and is arranged at an offset position of the reflector antenna so that the arrangement direction of the radiating elements is along the parallel movement direction of the parabola.

(Function) As described above, by using a parallel movement surface instead of a parabolic rotation surface as the reflection surface of the reflector antenna, the reflection plate of the reflector antenna can be formed by only bending without narrowing it down. As a result, if the reflector antenna is molded using a press technique, a sophisticated press technique is not required, and if the reflector antenna is molded by SMC, wrinkles or cracks are less likely to occur in the aluminum foil, making the molding easier.

Furthermore, since the reflector antenna can be formed into a rectangular shape, a stable reflector antenna can be obtained. This eliminates the need for an expensive stand when using the reflector antenna indoors.

Furthermore, since the shape is an elongated offset parabola, the advantages of the offset reflector antenna against snow accumulation and blocking are not impaired.

(Embodiment) Hereinafter, an embodiment of the present invention will be explained in detail with reference to the drawings. Fig. 1 is a perspective view showing the configuration of the antenna device of the first embodiment of the invention, and Fig. 2 is a perspective view showing the structure of the antenna device of the first embodiment of the invention. It is an exploded perspective view. The illustrated antenna device is constructed as a stationary type that is convenient for indoor use.

In FIG. 1, 11 is a reflecting plate. This reflector 11
is formed into a substantially rectangular shape by, for example, a metal plate or a resin plate having a reflective layer.

Reference numeral 12 denotes a frame on which the reflector 11 is mounted. This frame 12 also has a substantially rectangular shape, and the reflective plate 11 is attached to the back side of the frame 12.

13 is a fixing member for attaching the reflector 11 to the frame 12. That is, as shown in the side view of FIG.
22 and the fixing member 13, and is screwed to the frame 12, for example.

The left and right ridgeline portions 121 and 122 of the frame 12 form a parabola (Z-Y”) having an offset amount of F shown in FIG.
/4F), it curves toward the back side along the curve $1 (shaded area) of the Y coordinate section (E≦Y≦E+D). On the other hand, the upper and lower ridgeline portions 123 and 124 of the frame 12 are set in a straight line.

The reflecting plate 11 is made of a relatively flexible member, and when attached to the frame 12, it is curved along the shape of the ridgeline portions 121° and 122.

As a result, the reflector 11 can move in the Y coordinate section (E≦
It has the same reflective surface as the curved surface obtained by moving the curve (Y≦E+D) in parallel.

The above is the configuration of the flap antenna of this embodiment.

Next, the primary radiator and frequency converter will be explained.

In FIGS. 1 and 2, 14 is a primary radiator and 15 is a frequency converter.

As mentioned above, the reflector 11 is arranged in the Y coordinate section (E≦
By translating the curve Y≦E+D), it has the same reflective surface as the surface q. Therefore, if the radio waves from the satellite are parallel to the Z axis in Figure 4, they will be concentrated at the point on the Z coordinate meter. do.

Therefore, as the primary radiator 14, a primary F/i radiator 14 having a structure in which radiating elements are arranged linearly is prepared. This primary radiator 14 is arranged at the offset position so that the arrangement direction of its radiating elements is along the parallel movement direction of the curve. Thereby, incoming radio waves can be efficiently received.

As the primary radiator 14 having such a configuration, for example, there is a microstrip array antenna formed by arranging circularly polarized wave elements in series. The distance from each radiating element to the feed point (coupling part with the frequency converter) must be equal. As a radiating element, NHK Giken Monthly Report (November 1985)
There are several, as shown in FIG. 5 shows a primary radiator in which four-element subarrays are arranged in a row and fed at the center (in this case, it is for right-handed circularly polarized waves, and as in the antenna device of this embodiment, a reflector 11 When used as a primary radiator of an antenna device having a radiator, the plane of polarization is reversed at the reflector 11, resulting in left-handed circularly polarized waves).

The radio wave received by the primary radiator 14 is converted into a signal in a first intermediate frequency band by a frequency converter (for example, a BS converter) 15 connected to the primary radiator 14 . This frequency converter 15 also has the function of a stay that supports the primary radiator 14, and supports the primary radiograph 14 at its upper end, and its lower end is provided at the lower ridgeline part 124 of the frame 12. It is rotatably held by a holding part 16.

The above is the configuration of the main body of the antenna device.In order to be able to install the main body indoors, the first
As shown in the figure, it is rotatably attached to a mouth-shaped leg member 17. That is, the lower ridgeline portion 12 of the frame 12
Leg attachment tongue pieces 18.19 are formed at both ends of the leg member 17, and these tongue pieces 18.19 attach knob attachment pieces 22.2 to tongue pieces 20.21 formed at both ends of the leg member 17. They are rotatably connected by 23. Thereby, the antenna body can be inverted on the leg member 17, and the angle of elevation can also be adjusted.

According to this embodiment described in detail above, the following effects are achieved.

(1) Even when pressing technology is used to curve the reflecting plate 11, sophisticated pressing technology is not required.

This is because we used a parallel displacement surface instead of a parabolic rotation surface as the reflection surface of the reflector antenna.
This is because the reflecting plate 11 can be formed only by bending without using squeeze forming.

(As shown in FIG. 6, as the second reflective plate 11, a reflective layer 112 made of aluminum foil or the like is formed on a reinforcing resin layer 111, and a surface protective coating is applied on this reflective layer 112. 111113, even if SMC molding is used to curve the reflective plate 12, the molding will not become difficult.

This is because, as described above, since the configuration uses a parabolic parallel movement surface as the reflective surface, there is almost no need to take care to prevent wrinkles, cracks, etc. from occurring in the reflective layer 112.

(3) By using a flexible member as the reflecting plate 11 as in this embodiment, a highly accurate reflecting surface can be easily formed without using press technology or SMC molding.

This is because, as mentioned above, the parallel plane of the parabola is simple, so if the reflector 11 has flexibility, it can be transferred to the frame 1
This is because it can be easily curved by simply attaching it to 2.

(4) When installing a reflector antenna indoors,
a! 1 (ilIi) It does not require a stand and can be installed using only the leg members 17, which have a simple structure and are inexpensive.

This is because the reflector antenna can be formed into a rectangular shape, making it possible to obtain a stable reflector antenna.

(5) The advantages of the offset reflector antenna against snow accumulation and blocking are not impaired.

This is because the reflecting surface is formed using an offset parabolic parallel movement surface.

(6) It is possible to provide an antenna device that is easy to fold and is stable even in this folded state.

This is because the reflector antenna has an installation structure in which the reflector antenna is rotatably attached to a leg member 17 having a simple mouth shape, and because the reflector antenna has a rectangular shape that is stable to sit on. Note that FIG. 6 shows a side view of the leg member 17 in a folded state. As shown in the figure, the left and right ridgeline portions 121 and 122 of the frame 12 have protrusions 24 and 25 that have recesses into which the primary radiator 14 fits when the leg members 17 are folded.
(Figure 1 is also self-illustrating), and is designed to protect this primary radiator 14.

(7) Since the reflecting surface 11 is substantially square, a wider antenna aperture area can be secured in the same dedicated space compared to a conventional offset reflector antenna.

In other words, in the case of a conventional parabolic rotational surface or a flap antenna, if its diameter is D, the space required is D? and the resulting antenna aperture area is πD
It is 2/4. On the other hand, in the case of using the parallel movement plane of the parabola of this embodiment or using the flept antenna, it is possible to obtain the same opening area as the exclusive space D2. In other words, compared to the conventional method, it is possible to secure an antenna aperture area of π/4 (E jaw T> times) with the same exclusive area.
The gain is 1.04 (=10Jlog 1,
27) Leads to dB gain improvement. Therefore, with the same dedicated space and the same efficiency, there is an advantage that a high gain can be obtained.

(8) Since the frequency conversion fi 15 has the function of a stay that supports the primary radiator 14, the conventional stay is no longer necessary. As a result, the frequency converter does not protrude as in the conventional case, so a compact device can be realized, and the device can be made lighter by the weight of the stay. Moreover, if the leg members 17 are folded, it becomes quite compact, so it is also effective as a portable type.

In addition, by forming the product into a compact as described above, it can be sold in an assembled state, and there is an advantage for the user in that no assembly work is required.

FIG. 8 is a perspective view showing essential parts of a second embodiment of the invention.

In the illustrated antenna device, one end of a primary radiator 14 is supported by a frequency converter 15, and the other end is supported by a stay 26.

Even a configuration in which the feed point is set at the end of the primary radiator 14 instead of at the center can be used if power loss is not a problem.

FIG. 9 is an exploded perspective view showing the structure of a third embodiment of the present invention, and FIG. 8 is a side view as well.

In the previous embodiment, the antenna device was described as being usable indoors. In contrast, this embodiment provides an antenna device suitable for installation outdoors using a ball as described in FIG. 11 above. In this case, this embodiment is particularly characterized by the direction adjustment device of the ball mount type.

In FIGS. 9 and 10, two ribs 31 and 32 are integrally joined or molded on the back surface of the reflecting plate 11. A metal fitting 33 on the mouthpiece is attached to the ribs 31 and 32 so as to rub against the ribs 31 and 32.

A hole 34.35 serving as the center of rotation in the elevation direction and a hole 36.37 on an arc centered on the hole 34.35 are formed on the side surface of the metal fitting 33. Above rib 31.32
screws 38 through holes 34.35 and 36.37
．． 39 and screws 40, 41 to the metal fitting 33.

In this way, when the metal fitting 33 is attached or the flefter antenna is mounted, the ball 44 is sandwiched between the U-shaped pole h42.43 and the metal fitting 33, and then tightened.
It can be attached to 4.

In this embodiment as well, the same effects as in the previous embodiment can be obtained except for the installation cost.

Note that this invention is not limited to the three embodiments described above, and it goes without saying that various other modifications can be made without departing from the gist of the invention.

[Object of the Invention] As described above, according to the present invention, an offset antenna can be easily formed using a simple technique.
Furthermore, the antenna can be easily installed without using an expensive stand, making it possible to reduce the cost of the device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a first embodiment of the present invention;
FIG. 2 is an exploded perspective view, FIG. 3 is an exploded side view, FIG. 4 is a coordinate diagram for explaining the shape of the reflector in FIG. 1, and FIG. 5 is a primary view of the first embodiment. FIG. 6 is a side view for explaining the effect of the first embodiment, FIG. 7 is a side view of the radiator, and FIG. 8 is a second embodiment of the present invention.
FIG. 9 is a perspective view showing the configuration of an embodiment of the present invention.
An exploded perspective view showing an embodiment of the invention, FIG. 10 is also a side view,
FIG. 11 is a perspective view showing the configuration of an example of a conventional antenna device, FIG. 12 is a perspective view showing another example, FIG. 13 is a coordinate diagram for explaining the configuration of a conventional reflector, and FIG. The figure is a diagonal pA diagram showing the configuration of the antenna device of FIG. 11 for indoor use. DESCRIPTION OF SYMBOLS 11... Reflection plate, 12... Frame, 13... Fixing member, 14... Primary radiator, 15... Frequency converter, 16... Holding part, 17... Leg member , 18.19
,20°21.31.32...rib,22.23...
・Screw with knob, 24.25...Receiver part, 26...
Stay, 33...Metal fittings, 34, 35, 36.37...
・Hole, 38° 39.40.41...Screw, 42.43
...U-shaped bolt, 44...ball. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3 Figure 4 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] An offset reflector antenna whose reflecting surface is a curved surface obtained by parallelly moving a curved line in a predetermined section deviated from the center line of a parabola, and a radiating element arranged in a straight line. , arranged at an offset position of the offset reflector antenna, with the arrangement direction along the parallel movement direction of the curve.
An antenna device comprising: a secondary radiator; and a frequency converter that converts the radio waves received by the primary radiator into an intermediate frequency signal and supports the primary radiator.