JPH0380704A - Manufacture of dielectric lens antenna - Google Patents

Abstract

PURPOSE:To form the dielectric lens antenna brought to zoning by an injection molding method by forming a part of the dielectric lens antenna by an injection molding method by using a first metal mold, and subsequently, inserting the formed part into a second metal mold, forming a second part by the injection molding method and repeating it by a prescribed number of times in the same way. CONSTITUTION:To a projecting part 40p formed in the center part of the lower side metal mold 40, a recessed part 41r formed in the center part of the upper side metal mold 41 is fitted, and by injecting a liquid resin from resin injection ports G1, G2, a part 21 of a ring shape is formed. Subsequently, to the lower side metal mold 40 in which the part 21 is placed, the upper side metal mold 42 is fitted, and by injecting a liquid resin from resin injection ports G3, G4, a part 22 of a ring shape is formed on the upper side of the part 21. Also, to the lower side metal mold 40 in which the combined parts 21, 22 are placed, the upper side metal mold 43 is fitted, and by injecting a liquid resin from a resin injection port G5, a part 23 is formed on the upper side of the combined parts 21, 22. Accordingly, the dielectric lens antenna brought to zoning, formed by the combined parts 21, 22 and 23 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a zoned dielectric lens antenna.

[Prior Art] Conventionally, a dielectric lens antenna IO shown in FIG. 2 has been used to increase the directivity gain of a horn antenna. Generally, the dielectric lens antenna 10 has a circular entrance/exit surface, and has two entrance/exit surfaces: a curved surface 10a and a plane 10b perpendicular to the optical axis X. For example, radio waves radiated from a wave source F such as a horn antenna propagate along the optical axis X passing through the center of this dielectric lens antenna lO, and are also radiated from the wave source F at an angle θ The radio wave enters the dielectric lens antenna 10 at a point P on the entrance surface 10a, is refracted, passes through a point P' on the exit surface 10b, and then propagates in a direction parallel to the optical axis X. Therefore, the dielectric lens antenna lO receives the radio waves radiated from the wave source F,
After matching the phases at the output surface 10b, the light is emitted as a plane wave, thereby making it possible to obtain sharp directivity characteristics.

If the dielectric lens antenna IO constructed as described above is made of a dielectric material, it will be large in size, so in order to make it smaller and lighter, a dielectric lens antenna 20 shown in FIG. 3 is used. In this dielectric lens antenna 20,
As shown in Fig. 3, zoning is performed by cutting the dielectric lens into concentric strips with a thickness of 2 (hereinafter referred to as step depth 2), and a plurality of concentric steps with the optical axis X as the center. form. Here, the depth Z of the step is set such that, for example, the phase difference between each radio wave at point P'' and point Q' is an integral multiple of 3600, and the phases of the radio waves at point P' and point Q' are in phase. In addition, in a general zoned lens, the depth of each step is 20c, 20
c is parallel to the optical axis X, and is the radio wave output surface 20b+ of each step.

20b2 is perpendicular to the optical axis X. Note that if the wave source F is a point wave source, the incident surface 20a is formed by a rotational hyperboloid formed by rotating a hyperbola around an axis, and if the wave source F is a linear wave source perpendicular to the plane of the drawing, the incident surface 20a is is formed by a cylindrical hyperboloid created by vertically translating a hyperbola.

[Problems to be Solved by the Invention] Conventionally, the dielectric lens antenna IO shown in FIG. 2 has been formed by injection molding. However, when forming the zoned dielectric lens antenna 20 shown in FIG. 3 by injection molding, there is a large difference in the wall thickness of the dielectric lens antenna 20, so the difference in thermal expansion and contraction due to cooling causes sinks on the surface of the lens. It was impossible to form the desired shape due to the occurrence of cracks and the like.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a method for manufacturing a dielectric lens antenna that can easily form a zoned dielectric lens antenna by injection molding.

[Means for Solving the Problems 1] A method for manufacturing a dielectric lens antenna according to the present invention is a method for manufacturing a dielectric lens antenna zoned by forming a plurality of steps, the method comprising: using a first mold; A first part of the dielectric lens antenna is formed using an injection molding method.
a first step of molding the first part, and inserting the first part molded using the first mold into a second mold, and a part of the inserted first part; An injection molding space is formed by the inner surface of the second mold and the second part is formed by an injection molding method using the space to form a second part that is different from the first part and forms a part of the dielectric lens antenna. The method is characterized in that the dielectric lens antenna made of each of the parts is formed by repeating the second step a predetermined number of times.

[Operation] In the first step of the manufacturing method, a first part forming a part of the dielectric lens antenna is molded by injection molding using a first mold.

Next, in a second step, the first mold is placed in a second mold.
A first part molded using a mold is inserted, and an injection molding space is formed by a part of the inserted first part and the inner surface of the second mold, and the space is closed. A second portion, which is different from the first portion and forms a part of the dielectric lens antenna, is molded using the injection molding method. In this second step, since a part of the first part forms part of the injection molding space, a part of the first part is molded in close contact with the second part, A combination of the first part and the second part can be obtained.

Thereafter, by repeating the second step a predetermined number of times, it is possible to form the dielectric lens antenna in which the respective parts are combined.

As described above, each of the above parts has a simpler shape compared to a conventional zoned dielectric lens antenna, and by sequentially forming and combining the above parts, a zoned dielectric lens antenna with a complex shape can be created. Even a lens antenna can be easily formed by injection molding.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

First Embodiment FIG. 5 is a longitudinal sectional view of a zoned dielectric lens antenna according to the first embodiment of the present invention.

In FIG. 5, this dielectric lens antenna is arranged in a plane perpendicular to the optical axis of each zone and for each zoned area.
It consists of three parts 21, 22, and 23 divided by using the plane including ob1.20b2 as the dividing boundary plane. Here, each of the portions 21 and 22 has a concentric ring shape centered on the optical axis X, and the portion 23 has a convex lens shape centered on the optical axis X and one surface of which is flat.

FIGS. 1A, 1B, and 1C are longitudinal cross-sectional views showing the manufacturing process of the zoned dielectric lens antenna of the first embodiment. The manufacturing process will be explained.

First, as shown in FIG. 1(A), the convex part 40p formed in the central part of the lower mold 40 is fitted into the recess 41r formed in the central part of the upper mold 41, and the lower part of the mold 40 is lowered. After the upper mold 41 is fitted into the side mold 40, a resin injection port Gl is formed in the upper part of the upper mold 41.

A ring-shaped portion 21 is formed by injecting liquid resin from G2 and cooling it. After this, only the upper mold 41 is removed.

Next, as shown in FIG. 1(B), the upper mold 42 is fitted into the lower mold 40 on which the portion 21 is placed, and the portion 21
After forming the injection molding space formed by the upper surface and the mold 40.42, the resin injection port G3. A ring-shaped portion 22 is formed above the portion 21 by injecting liquid resin from G4 and cooling it.

Here, since the temperature of the injected liquid resin is high, the upper surface of the portion 21 is melted and molded in close contact with the lower surface of the portion 22. Therefore, the combined ring-shaped part 2
1 and a portion 22 are formed. After this, only the upper mold 42 is removed.

Furthermore, as shown in FIG. 1(C), the combined part 02
After fitting the upper mold 43 into the lower mold 40 on which the parts 1 and 22 are placed, and forming an injection space formed by the upper surface of the portion 22 and the molds 40 and 43, the upper part of the upper mold 43 is Liquid resin is injected from the formed resin injection port G5 and then cooled to form a portion 23 above the combined portions 21 and 22. Here, since the temperature of the injected liquid resin is high, the upper surface of the portion 22 is melted and molded in close contact with the lower surface of the portion 23. Therefore, the combined part 2
A zoned dielectric lens antenna consisting of 1.22.23 is formed.

Here, as shown in FIG. 6, each divided portion 21a
, convex portions 21p1+ 21p on the boundary surfaces of 22a, respectively.
z, 22p+, 22px, while each part 22a
, 23a, the convex portion 21pl+ 211)2
．． 22p1.22+)2 recessed portions 22r that fit respectively
, , 22r, , 23r, , 23r may be formed and each portion 21, 22, 23 may be closely fitted. Thereby, it is possible to improve the adhesion of each of the above-mentioned interfaces.

Second Embodiment FIG. 7 is a longitudinal sectional view of a zoned dielectric lens antenna according to a second embodiment of the present invention.

In FIG. 7, this dielectric lens antenna has a surface 2 in the depth direction 2 of each zoned area and each step.
It consists of three parts 31, 32, and 33 divided by using a plane parallel to the optical axis X including 0c+ and 20c as a dividing boundary plane. Here, each of the portions 31 and 32 has a ring shape centered on the optical axis X, and the portion 33 has a substantially cylindrical shape centered on the optical axis X.

FIGS. 4A, 4B, and 4C are vertical cross-sectional views showing the manufacturing process of the dielectric lens antenna with a dielectric lens antenna according to the second embodiment. The manufacturing process of the lens antenna will be explained.

First, as shown in FIG. 4(A), the convex part 40p formed in the central part of the lower mold 40 is fitted into the recess 44r formed in the central part of the upper mold 44, and the lower part After fitting the upper mold 44 to the mold 40, liquid resin is injected from the resin injection ports G6 and G7 formed in the upper part of the upper mold 44, and then cooled to form the ring-shaped portion 31. do. After this,
Only the upper mold 44 is removed.

Next, as shown in FIG. 4(B), the portion 31 is placed I; the upper mold 45 is fitted into the lower mold 40, and the portion 3
1 and the mold 40.45, a resin injection port G8. A ring-shaped portion 32 is formed on the inner peripheral side of the portion 31 by injecting liquid resin from G9 and cooling it. Here, since the temperature of this injected liquid resin is high,
The inner circumferential surface of the portion 31 is melted and molded in close contact with the outer circumferential surface of the portion 32. Therefore, combined ring-shaped portions 31 and 32 are formed. After this, only the upper mold 45 is removed.

Furthermore, as shown in FIG. 4(C), the combined part 3
After fitting the upper mold 46 to the lower mold 40 on which the portion 1.32 is placed and forming an injection molding surface consisting of the inner peripheral surface of the portion 32 and the mold 40.46, the upper mold 46 is After injecting liquid resin from the resin injection port GlO formed at the top, it is cooled, and a portion 3 is formed on the inner peripheral side of the above-mentioned combined portions 31 and 32.
Mold 3. Here, since the temperature of the injected liquid resin is high, the inner circumferential surface of the portion 32 is melted and molded in close contact with the outer circumferential surface of the portion 33. Therefore, the zoned dielectric lens antenna is formed by the combined portions 31, 32, and 33.

FIG. 8 is a longitudinal sectional view showing the structure of a zoned dielectric lens antenna which is a modification of the second embodiment of the present invention.

As shown in FIG. 8, the divided portion 31a.

Steps 31p, 32r, 32p, and 33r are formed on 32a and 33a, respectively, so that the boundary surface of each step is inclined at an angle smaller than 90 degrees with respect to the optical axis X.
Each portion 31a, 32a, 33a is arranged so that the step 31p fits into the step 32r and the step 32p fits into the step 33r.
They may be fitted closely together. As a result, each part 31
The bonding area of the interface between a, 32a, and 33a can be increased, thereby improving their adhesion.

As explained above, the dielectric lens antenna is divided into a plurality of zoned parts with a simple structure, and each divided part is sequentially formed by injection molding and formed in close contact with each other. Even in the case of a zoned dielectric lens antenna having a complicated shape, each of the above parts can be easily formed by injection molding.

In the above embodiments, a case has been described in which one surface of the dielectric lens antenna is a flat surface, but the present invention is not limited to this, and it may be a curved surface depending on the type of wave source and the type of beam. In this case, each boundary surface that divides the dielectric lens antenna is not parallel to the optical axis X. Here, in order to reduce the loss of propagating radio waves, it is preferable that each of the boundary surfaces is set in the direction in which the radio waves travel.

[Effects of the Invention] As detailed above, according to the present invention, the first part forming a part of the dielectric lens antenna is molded by the injection molding method using the first mold. a step of inserting a first part molded using the first mold into a second mold, and combining a part of the inserted first part with the second part;
a second step of forming an injection molding space formed by the inner surface of the mold and molding a second part using the injection molding method; The dielectric lens antenna made up of each of the above parts is formed by repeating the same number of times. Therefore, each of the divided parts has a simpler structure compared to the conventional zoned dielectric lens antenna, and does not have to be complicated. Even a zoned dielectric lens antenna having a similar shape has the advantage that it can be easily formed.

[Brief explanation of drawings]

Figures 1 (A), (B), and (C) are longitudinal cross-sectional views showing the manufacturing process of a zoned dielectric lens antenna according to the first embodiment of the present invention, and Figure 2 is a conventional dielectric lens antenna. Longitudinal cross-sectional view of antenna FIG. 3 is a vertical cross-sectional view of a conventional zoned dielectric lens antenna. FIGS. 4(A), (B), and (C) are vertical cross-sectional views showing the manufacturing process of a zoned dielectric lens antenna according to the second embodiment of the present invention; FIG. FIG. 6 is a longitudinal cross-sectional view showing the structure of a zoned dielectric lens antenna which is an embodiment of the present invention; FIG. 7 is a vertical cross-sectional view showing the structure of a zoned dielectric lens antenna according to a second embodiment of the present invention, and FIG. FIG. 2 is a vertical cross-sectional view showing the structure of a dielectric lens antenna. 21.22, 23, 31.32.33...Divided parts, 20cI, 20c1...Depth of step, Z-direction surface, 2ob
l, 20bi'...plane perpendicular to the optical axis of the step, 40 to 4
6...Mold. Figure 1 (A) Figure 1 (8) Figure 4 (A) Figure 4 + 8) Figure 4 (C) 1 1 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] (1) A method for manufacturing a zoned dielectric lens antenna by forming a plurality of steps, the method comprising: forming a part of the dielectric lens antenna by an injection molding method using a first mold; a first step of molding the part; and a first molded part using the first mold in a second mold.
is inserted, an injection molding space is formed by a part of the inserted first part and the inner surface of the second mold, and the first part is molded by injection molding using the space. and a second step of molding a second portion that is different from the above dielectric lens antenna and forms a part of the dielectric lens antenna. A method of manufacturing a dielectric lens antenna, characterized in that the dielectric lens antenna is formed by a portion.