JPH03201704A - Parabolic antenna system - Google Patents

Abstract

PURPOSE:To make the weight of a reflection mirror light, to reduce the window pressure weight and to relieve the load onto a mount support without deteriorating the antenna efficiency by making plural throughholes to the reflection mirror formed with a self-standing member and selecting the diameter and the pitch of the throughholes. CONSTITUTION:The diameter and the pitch of plural throughholes 51 are selected to satisfy inequality I in a reflecting mirror 31 with the plural throughholes 51 made thereto, where L is the diameter of the throughhole, Ad is its total area, A is an area of a reflecting mirror and lambda is a wavelength of a received radio wave in the inequality I. Moreover, a base member 52 of the reflection mirror 31 is made of an unsaturated polyester and a glass fiber reinforced resin and a reflecting layer 53 made of a metallic plate with a high reflectance of a radio wave such as aluminum press-formed in matching with the shape of a parabolic curved face of the member 52 is adhered to an inner face (aperture) of a bowl by means of the adhesion. Thus, the wind resistance and the reduced weight are maximized without deteriorating the reception performance.

Description

[Detailed Description of the Invention] [Objective of the Invention 1 (Field of Industrial Application) The present invention is directed to satellite broadcasting and satellite communication 1. ), etc., and is particularly designed to be lighter and have improved wind pressure resistance.

(Prior Art) Generally, a reflecting mirror of a parabolic antenna is formed of an integral structure of a metal plate. However, in recent years, with the advancement of satellite broadcasting, etc.
Parabolic antennas are increasingly being installed in ordinary homes. For installation in a general household, it is best to use one that is easy to install and has minimal damage. Therefore, we used light and durable fiber reinforced resin (FRP) as the base material of anti-Ql 11, and attached a thin metal plate that reflects radio waves to the surface (opening surface) side.
A parabolic antenna made by Norm construction has been put into practical use.

Such a parabolic antenna, as shown in Figure 6,
The main elements are a reflection 111 having a parabolic plate shape and a primary sword device 2 that receives m-waves converged by the reflection I11. -order radiator 2 is integrated with a frequency converter.

The overall external shape of the reflecting mirror 1 is a bowl shape with the opening side being concave, and the back surface of the reflecting mirror 1 is attached to a ball 3 via a mount 4.

The cross-sectional structure of the reflecting mirror 1 is as shown in FIG.
Reflective layer7. It has a three-layer structure of epoxy resin 8. The base material 6 is made of fiber-reinforced resin and is formed into a plate shape having the above-mentioned curved surface. Against! The 8 pieces 7 are formed by pressing a metal plate to match the curved surface of the base material 6, and are attached to the open surface of the base material 6 by adhesive. The evo main resin 8 protects the reflective layer 7 from the outside air and is formed by coating.

In such a parabolic antenna device, since the reflecting mirror 1 is bowl-shaped, the wind pressure load is large. In addition, although the reflector 1 is made of fiber-reinforced resin, it is small (60 cm) and heavy.For this reason, the ball must have a strong structure with a large diameter. Furthermore, there was a problem in installing it on a lift that is not strong enough, such as a balcony.

In addition, for 1)-alignment, the load on the drive iF!IJ device increases even for a parabolic antenna "tA Mt" whose reflecting mirror is automatically rotated by a drive device dedicated to a motor.Furthermore, Parabolic antenna W on the balcony fence
Install i! This can create a feeling of oppression as it blocks the view from the room, and also blocks the sun, worsening the living environment.

On the other hand, one of the conventional methods for reducing weight and improving wind pressure resistance is to use a wire mesh for the anti-tA mirror. As a result, the weight of the reflector is significantly reduced, and the wind passes through the mesh, reducing the load caused by wind pressure.

In this case, the antenna efficiency can cover a certain efficiency as the mesh is thinned.

However, as shown in FIG. 8, the above parabolic antenna device using a wire mesh has an umbrella-like structure in which fan-shaped pieces are connected by a frame 19 in order to form the wire mesh 20 in a parabolic shape. Therefore, it is not possible to achieve sufficient weight reduction. The wire mesh 2° does not form an accurate rotating object surface in the circumferential direction of the reflecting mirror, and inevitably high surface viscosity cannot be obtained, so it exhibits sufficient performance in a small parabolic antenna device. Therefore, it is not suitable for general household use.

(Problems to be Solved by the Invention) In conventional parabolic antenna devices, the reflecting mirror is subject to wind pressure, and there is a problem in installing it in a place where the strength is not sufficient, such as a balcony. Additionally, problems such as obstructed vision and a feeling of pressure were pointed out.

The present invention eliminates the above-mentioned problems and provides an antenna device in which the weight of the anti-I mirror is reduced and the wind pressure load is reduced without reducing the antenna efficiency, and the installation does not place any burden on the support. purpose.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a parabolic antenna device in which a plurality of through holes are formed in a reflecting mirror formed of an autonomous member, in which the diameter of the through holes is The present invention is characterized in that the diameter and pitch of the through holes are selected so as to satisfy the following conditions, where the total area is 8d, the area of the reflecting mirror is A, and the wavelength of the received radio wave is λ.

(Function) According to the present invention, it is possible to obtain the time limit of the diameter 1-of the through hole, and to improve the ll1fa and secondary wind pressure properties.

(Example) Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

1 to 3 are configuration diagrams showing one embodiment of a parabolic antenna device according to the present invention, in which FIG. 1 is a perspective view showing the whole, and FIG. 2 is a transparent An explanatory diagram showing the holes, FIG. 3 is a cross-sectional view of the unfolded copper mirror.

That is, in the parabolic antenna device shown in FIG. 1, a plurality of round through holes 51 penetrating from the concave surface to the back surface of the expanded @31 formed to form a parabolic curved surface can be simply calculated using the following mathematical formula. It is formed with a screw to a predetermined size. In addition, the figure shows a case where the ball 38 is installed on a balcony, and the ball 38 is attached to the balcony column 41 via a metal fitting 39, and the ball 38 is attached to the upper end of the ball 38 via an elevation angle adjusting metal fitting 37.
Reflection @31. -Next radiator 32. Support member 33. It is equipped with an antenna element consisting of a converter 34.

To explain the through holes 51 in more detail, the through holes 51 are each formed in a round shape at the intersections of equally spaced parallel lines in three directions that intersect at an angle of 60 degrees, respectively, as shown in FIG. Here, the diameter (hereinafter referred to as diameter) of the through holes 51 is defined as L1, and the distance 11 ft (pitch) between adjacent through holes 51 is defined as P.

Further, as shown in FIG. 3, the reflecting mirror 31 has a base material 52 made of unsaturated polynisdel and glass fiber reinforced resin. On the inner surface (opening surface) of the bowl surface, a metal plate with high radio wave reflectance such as aluminum is press-molded to match the parabolic curved surface of the base material 52. be done.

Further, the reflective layer 53 is coated with Evo 1 resin 54. Such a reflecting mirror 31 is, for example, a base material 5.
After forming the reflective layer 53 on the substrate 2, the through holes 51 are formed using a drilling means such as a drill. Formed after peeling off the resin 54.

In this embodiment, in the above configuration, the efficiency of a normal antenna without holes is assumed to be 100%, and the diameter of the through hole 51 (hereinafter referred to as IL) and its pitch P are determined for the practically allowable efficiency. This is an equation to determine whether to set the equation to 1). I231 is the through hole 51
The wider the diameter, the less wind pressure will be applied, but the efficiency will be lower than I. Furthermore, the smaller the total area of the through holes 51, the lighter the weight, but the lower the efficiency. Therefore, based on the formula established by this invention, we have attempted to easily find the relationship between 1- and P that maximizes both kite pressure resistance and weight reduction without sacrificing efficiency. It's ours.

First, FIG. 4 is a graph showing the relationship between the diameter of the through hole 51 and the antenna efficiency. The vertical axis is a normal antenna at 10
It shows the antenna efficiency (%) when it is 0%, and the horizontal axis is
This shows the size of the radius expressed in units of the wavelength λ of the received radio waves. Note that the wavelength λ is 25 mm assuming 12GH7.

The above graph shows that up to 0.145λ, the antenna achieves 100% performance, which is the same as a normal antenna, and almost always maintains the same efficiency of 100%.If the diameter L- is made larger than 0.145λ, As a practical guideline, if the efficiency is allowed to be 90%, it can be seen that it may be expanded to approximately 0.2λ, although some variation will occur.

However, even if the size of L is determined, the through hole 51 cannot be drilled unless the pip is determined.

Therefore, in this invention, the through hole 51 occupied by the reflecting mirror 31 is
The antenna efficiency characteristics were measured when the total area ratio (hereinafter referred to as aperture ratio) and the value of L were varied.

FIG. 5 is a graph showing the antenna efficiency characteristics measured by varying the aperture ratio and (\L) of the through hole 51 in various combinations. That is, the vertical axis represents the antenna efficiency, and the horizontal axis represents the antenna efficiency. is the product of the ratio (1,/λ) to the wavelength of the received A3 radio wave and the frontage ratio (which becomes a scalar weight).
Vertical on the left side @ [Relative advantage of which antenna does not have a through hole ()
9 (dB).

According to this graph, when the product value is 0.05 or less, 10
If the efficiency is maintained at 0% and the value is decreased below this value, the antenna efficiency begins to decrease linearly.

If the antenna efficiency is 90%, the product value is 0.13:L.
You can make it bigger with . Anbuna relative interest of this moment 4! #1, -0.5dB.

The same-day rate is expressed as Ad/A, where A is the area of the reflecting mirror 31 and A is the total area of the through holes 51, and corresponds to the rate of weight reduction due to the through holes 51. Now, if we try to reduce the antenna weight by one-fifth, Ad/A=0.2,
In order to achieve antenna efficiency of 90%, L/R should be smaller than 0.65. From this, λ is 25M
Therefore, the maximum size of the ship can be 16.25 m.

Also, at the same 90%, if you try to raise the weight J to 1/5, it will become smaller than Li3, and you will have to make it smaller, and the weight will be reduced to 1/5. If you try to make it smaller (make it heavier), Li3 becomes larger and L can be increased.This allows you to reduce the weight while maintaining the required antenna efficiency, and improve the F!4 wind pressure and texture. You can find Nizurushi and P.

That is, in the case of a round through hole 51 as shown in FIG. 2, the aperture ratio can be expressed in the table below using the diameter and bit P.

In the case of FIG. 2, there are three sectors of 1/6π in the equilateral triangle with the - side of bit P, that is, the half circle of the through hole 51. Assuming that the through hole 51 is formed as shown in FIG. According to the above formula, since the aperture ratio is proportional to the square of the ratio of L and P, the pitch P can be ejected by finding the frontage ratio for the square.

In the case of the round holes shown in Figure J3.412, if the product is 0.125 or more, the abrasive material between the holes will become thinner, and the material may be cut when forming the holes, etc., from the point of view of acidity. I can't hope for anything less than this. Further, if the aperture ratio /λ product value is up to 0.05, it is possible to reduce the weight and reduce the wind pressure while maintaining the antenna efficiency at 100%. The above Ia value is 0.13
If the antenna efficiency is allowed up to 90%, the relative gain is -Q, 5 dB. Also, if it is allowed up to 0.38, the antenna efficiency will be 60% and the relative gain will be -2,
It becomes OdB.

As described above, according to the antenna device according to the present invention, by selecting the appropriate value "None" and "P", it is possible to maximize ventilation and light weight without deteriorating reception performance. In addition, when installed on a balcony, it does not obstruct the view from the room and does not feel oppressive, making it suitable for Japanese housing conditions and allowing for the right movement of narrow spaces.

Furthermore, by making the reflector a light star, there is an advantage that the driving device for direction adjustment can be configured with a low-power circuit.

The base material that forms the reflective mirror is fiber reinforced resin.

It is a self-supporting member made of metal, etc., and is distinguished from one made of material parts, such as a wire mesh.

[Effects of the Invention] As explained above, according to the present invention, it is possible to provide a parabolic antenna that can maximize both wind pressure resistance and light weight.

[Brief explanation of drawings]

1 to 3 are perspective views, explanatory views, and cross-sectional views showing one embodiment of the parabolic antenna device according to the present invention, and FIG. 4 is a graph measuring the relationship between the diameter of the through hole and the antenna efficiency.
Figure 5 1. A graph showing the antenna efficiency characteristics considering the diameter of the through-hole and the aperture [1 ratio], Fig. 6 is a perspective view showing a conventional parabolic antenna device, and Fig. 7 is a cross section showing the angle 9112 of the antenna device in Fig. 6. FIG. 8 is a perspective view showing another conventional parabolic antenna device.
・Support member, 34... Converter, 37... Elevation adjustment fitting, 38... Ball, 39... Mounting fitting,
41...Balcony column, 51...Through hole,...Through hole diameter, P-...Through hole pitch, 52...Base material, 53...
...Reflection'? , 54...]] Nipo 4-Si resin 1r
lA g)lh+□ship

Claims (1)

[Claims] A parabolic antenna device in which a plurality of through holes are bored in a reflecting mirror formed of a self-supporting member, wherein the diameter of the through holes is L, the total area is A_d, and the area of the reflecting mirror is A. A parabolic antenna device characterized in that the diameter and pitch of the through holes are selected so as to satisfy 0<L/λ×A_d/A≦0.38, where λ is the wavelength of a received radio wave.