JPH0425203A - Dust-proof film for waveguide and its manufacture - Google Patents

Abstract

PURPOSE:To prevent generation of an insertion loss due to an adhesives by adhering the adhesives to an outer circumferential ridge area and providing a transmission area of an electromagnetic wave without any adhesion to an area surrounded by the outer circumferential ridge area. CONSTITUTION:An adhesives 12 is adhered to the entire face of one side of exfoliation paper 13b, exfoliation paper 13a is adhered on the adhesives 12 to form three-layer structure double-side tape 20. Then a cylindrical cutter blade 18 is prepared to cut the double-side tape 20 circularly. Then the lower side exfoliation paper 13a is exfoliated and removed, adhered to a sheet film 11 to form a sheet material 17 provided with a transmission area 15 for an electromagnetic wave. Thus, no adhesives is entirely adhered to an area of a dust-proof film 10 through which an electromagnetic wave is transmitted and the reflecting and transmitting quantity of the electromagnetic wave is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a dustproof film for a waveguide forming a primary radiator of a parabolic antenna, and a method for manufacturing the same.

[Conventional technology]

Recently, television broadcasting using satellites has become popular. In satellite broadcasting, as shown in FIG. 11, radio waves from a satellite are converged by a reflecting mirror of a parabolic antenna 1 installed outdoors, and received by a -order radiator 2. The received signal is then processed by a tuner installed indoors and displayed on a television receiver.

The primary radiator 2 of the parabolic antenna 1, as shown in FIG. LNB (L
ow No1se Block converter)5
It is formed by. LNB 5 is a type of waveguide. The primary radiator 2 shown in FIG. 12 includes a polarizer 6 inside a waveguide 4. The primary radiator 2 shown in FIG. The polarizer 6 is a device that identifies cross-polarized waves in wireless communication systems. In frequency bands above the microwave band, two orthogonal polarizations (vertical and horizontal polarization in linear polarization) are used simultaneously to increase communication capacity and avoid interference between wireless channels. . On the receiving side, the coil 7 of the polarizer 6 is operated to cause Faraday rotation in the received electromagnetic waves, thereby distinguishing vertically polarized waves and horizontally polarized waves of the cross-polarized waves.

Each component incorporated into such a second radiator 2 is manufactured, stored and managed individually, and assembled at each installation site. Therefore, waveguide 4 and LNB 5
Fine dust had entered the waveguide 4 and LNB 5 during storage in a warehouse after manufacture, during the distribution process, and during installation and use. When dust enters, the radio waves passing through the transmission path inside the pipe collide with the dust and are diffusely reflected, or are significantly attenuated or absorbed, which is a drawback of causing so-called intrusion loss.

Conventionally, in order to solve this drawback of insertion loss, as shown in FIG. A dustproof film 9 made of 9a was attached to prevent dust from entering the interior. Note that a release paper (not shown) is attached to the adhesive 8 side of the dustproof film 9 before use.

[Problem to be solved by the invention]

However, in the conventional dustproof film 9, the adhesive 8 is adhered to the entire surface of one side, and the dustproof film 9
The electromagnetic waves that penetrate into the waveguide 4 and the LNB 5 are reflected, attenuated, or absorbed by the adhesive 8, which is another disadvantage of causing insertion loss. there were. In other words, this type of satellite broadcast receiving equipment had a fatal drawback in that the gain of the waveguide decreased, which adversely affected the receiving ability of the parabolic antenna 1. This was also the case with other equipment other than satellite broadcasting that uses waveguides.

[Means to solve the problem]

The present invention has been made in view of the above-mentioned problems of the prior art, and is an object of the present invention to provide a dustproof film for waveguides that does not cause insertion loss, and a method for manufacturing the same.

Therefore, the technology of the dustproof film adopted by the present invention in order to solve the above problem is that an adhesive is attached to the outer peripheral area,
The area surrounded by the outer peripheral area is characterized in that an electromagnetic wave transmission area is provided that is completely free of deposits.

In addition, the method for manufacturing the dustproof film involves cutting a double-sided tape into a predetermined shape, peeling off the release paper on one side, and adhering it to a film made of synthetic resin such as polyimide, thereby cutting off the double-sided tape. By forming a sheet material with an electromagnetic wave transmitting region to which no adhesive or release paper is attached, and cutting the sheet material into a predetermined shape on the outer circumferential side of the electromagnetic wave transmitting region, the electromagnetic wave transmitting region is formed. An outer periphery area is formed on the outer periphery side to which a release paper is attached via an adhesive.

[For production]

In the dustproof film of the present invention, no adhesive is attached to the area through which electromagnetic waves are transmitted, so that unlike conventional films, insertion loss due to the adhesive does not occur.

In addition, in the method of manufacturing a dustproof film, first, the release paper on one side of a double-sided tape cut into a predetermined shape is peeled off and adhered to the film, so that only the film exists in the area of the cut part. A sheet material is molded with a region that transmits electromagnetic waves. Then, by cutting the entire sheet material on the outer peripheral side of this transmission area,
An outer periphery area is formed on the outer periphery side of the electromagnetic wave transmission area to which a release paper is attached via an adhesive to form a dustproof film.

With this, it is possible to manufacture a dustproof film simply by cutting and cutting out the three-layered sheet material, compared to the case where adhesive and release paper are attached only to a part of the outer peripheral area. Its manufacture is extremely simple.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and method of the present invention will be explained below based on embodiments shown in the drawings. Note that the same reference numerals as in the conventional case represent the same members.

FIGS. 1 and 2 show a dustproof film IO according to an embodiment of the present invention. In this example, a film 11 manufactured by DuPont under the trade name Kapton, which is a polyimide resin film, is prepared, and a double-sided tape 20 manufactured by Sony Chemical Corporation called 74100 is attached to the outer periphery of the film 11. An outer peripheral edge region 14 is formed. Note that the double-sided tape 20 has two sides, as shown in FIG.
Release papers 13a and 13b are attached to both sides of the adhesive 12, and when it is attached to the film 11 as shown in FIG. ing. Further, the dustproof film 10 forms an electromagnetic wave transmission region 15, which is a region surrounded by the outer peripheral region 14, and is a region to which no adhesive 12 is attached.

In addition, as shown by the chain line in FIG. 2, a handling piece 16 is provided on a part of the outer periphery of the release paper 13a, and the handling piece 16 is gripped to prevent finger marks from adhering to the electromagnetic wave transmission area 15 during pasting. Therefore, it is also possible to remove the release paper 13a and position the entire dustproof film 10 in one step. This handling piece 16
can also be formed on the film 11 side.

The dustproof film 1o configured as described above is manufactured in the following manner. That is, first, as shown in FIG. 4, the adhesive 12 is applied to the entire surface of one side of the release paper 13b. Subsequently, as shown in FIG. 5, a release paper 13a is attached on top of this adhesive 12, and a sheet-like double-sided tape 2 with a three-layer structure is attached.
form 0. Then, as shown in FIG. 6, prepare a cylindrical cutting blade 18 and cut out the double-sided tape 20 in a circular shape (shape W3 in FIG. 7).Next, as shown in FIG. The release paper 13b on the side is peeled off and, as shown in FIG.
form. After that, as shown in FIG. 10, the sheet material 17 may be cut with a cutting blade 19 having a larger diameter than the cutting blade 18. As a result, the adhesive is applied to the outer circumferential side of the electromagnetic wave transmission area 15. It is possible to manufacture the dustproof film 10 by attaching the release paper 13a through the film 12.

For example, as shown in FIG. 3, the dustproof film 10 manufactured in this way is prepared by peeling off the release paper 13a and then removing the release paper 13a.
Opening 4a of waveguide 4 via adhesive 12 in outer peripheral area 14
It is used by being attached to the side end face. In this case, the electromagnetic wave transmitting region 15 to which no adhesive 12 is attached needs to be equal to or slightly larger than the opening 4a.

The reason for this is that when the size of the transmission area 15 is smaller than the opening 4a, the adhesive 12 is exposed to the inner surface of the waveguide 4 and is transmitted through the waveguide 4 as in the conventional case. This is because it causes insulator loss of electromagnetic waves.

Therefore, when attaching the dustproof film IO to the waveguide 4, if the release paper 13a is to be peeled off and removed, it is sufficient to hold the handling piece 16.
The dustproof film 10 can be positioned with respect to the waveguide 4. Therefore, by forming the handling piece 16, it is possible to perform the work of attaching the dustproof film 10 accurately, quickly, and easily. By the way, film 1
Another method of attaching 1 is to apply the adhesive 12 to the end face on the side of the opening 4a, and then attach the film 11 alone. However, in this case, adhesive 1
Conventionally, the adhesive 12 could not be used because of problems such as the coating thickness of the adhesive 2 becoming non-uniform and the adhesive 12 protruding into the electromagnetic wave transmission area 15, causing defects.

The following table shows the results of experiments conducted by the applicant to confirm the effects of the present invention. The sample used in the experiment was a waveguide 4 made of zinc alloy with an inner diameter of 21mm and an outer diameter of 25mm, and a conventional dustproof film 9 shown in FIG. 10 was attached to the end face on the opening 4a side. and a third comparative field in the waveguide 4.
A product of the present invention to which a dustproof film 10 of the present invention shown in the figure was attached was used. The film material used was Kapton film with a thickness of 25 μm manufactured by DuPont, and the adhesive used was T4100 manufactured by Sony Chemical Co., Ltd. in a thickness of 45 μl.

In the experiment, the amount of electromagnetic waves transmitted through each of the dustproof films 9 and 10 was subtracted from the amount of electromagnetic waves projected at 10.95 to 12.75 GllZ to determine the amount of reflection and the amount of absorption, which are reflection losses.

Table 1 As is clear from this table, the product of the present invention is 0.5 dB better in return loss than the conventional product, and the VS
0.05 better in WR. These numbers indicate performance that is one rank higher in the field of this type of satellite broadcasting equipment.

By the way, the present invention is not limited to the above-mentioned embodiments, and can be modified as appropriate. For example, the waveguide may include circular waveguides, rectangular waveguides, ridge waveguides, etc. However, the dustproof film of the present invention can be used for any of them. In that case, it goes without saying that the shape and size of the dustproof film are changed to correspond to those of the waveguide.

In addition to polyimide resin, resin materials such as Teflon can also be used as the dustproof film.

〔Effect of the invention〕

As explained above, in the dustproof film of the present invention,
Since no adhesive is attached to the area of the dustproof film through which electromagnetic waves are transmitted, it is possible to reduce the amount of reflection and absorption of electromagnetic waves. It is possible to significantly reduce the so-called reflection loss of electromagnetic waves, and it is possible to significantly improve the performance of satellite broadcasting equipment and the like.

Furthermore, according to the manufacturing method of the present invention, a dustproof film can be manufactured by simply cutting and cutting out a sheet material having a three-layer structure, and can be manufactured extremely accurately, quickly, and easily.

[Brief explanation of the drawing]

Figures 1 to 10 relate to one embodiment of the present invention, where Figure 1 is a longitudinal cross-sectional view of a dustproof film, Figure 2 is a plan view of the same, and Figure 3 is a diagram showing how a dustproof film is attached to a waveguide. 4 to 10 are vertical sectional views showing the manufacturing process of the dustproof film, FIG. 11 is a schematic side view of the parabolic antenna, and FIG. 12 is a portion of the primary radiator. A cross-sectional side view and FIG. 13 are vertical cross-sectional views showing a state in which a conventional dustproof film is attached to a waveguide. 4... Waveguide 10... Dustproof film 11
...Film 12...Adhesive 13a, 1
3b...Release paper 14...Outer peripheral area 15...Transparent area Patent applicant: Inax Co., Ltd. Attorney: Toshihiko Uchida

Claims (4)

[Claims] 1. 1. A dustproof film for a waveguide, characterized in that an adhesive is adhered to the outer peripheral edge area, and an area surrounded by the outer peripheral edge area is provided with an electromagnetic wave transmission area free of any deposits. 2. The dustproof film for a waveguide as claimed in claim 1, wherein a release paper is attached to the portion to which the adhesive is applied. 3. The dustproof film for a waveguide according to claim 1 or 2, wherein a removable handling piece is provided on a part of the outer periphery of the dustproof film or release paper. . 4. By cutting the double-sided tape into a predetermined shape, peeling off the release paper on one side, and adhering it to a film made of synthetic resin such as polyimide, adhesive and release paper are applied to the area where the double-sided tape was cut off. By forming a sheet material with an electromagnetic wave transmitting area to which no electromagnetic wave is attached, and cutting the sheet material into a predetermined shape on the outer circumferential side of the electromagnetic wave transmitting area, the adhesive can be attached to the outer circumferential side of the electromagnetic wave transmitting area. 1. A method for producing a dustproof film for a waveguide, comprising: forming an outer peripheral area to which a release paper is attached.